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Insect - plant interactions and induced plant defence
A selection of abstracts is included below to illustrate tritrophic interactions between plants, herbivores and parasitoids.
The recent Novartis Foundation symposium on 'Insect–plant interactions and induced plant defence' shed new light on some of the intriguing and sophisticated mechanisms that plants use to defend themselves from the constant threat of insect attack.
When a herbivore such as a caterpillar begins to feed on a leaf, the plant responds by releasing a complex blend of as many of 100 volatile chemicals, known as semiochemicals (literally, 'sign chemicals'). These chemicals act as an airborne SOS signal, revealing the presence of the herbivore to its natural enemies, either predators or parasitoids, which then come to the plant's assistance.
At first glance, this 'tritrophic' interaction appears simple and elegant, but the many twists and turns to the story discussed at the meeting reveal a complex set of interrelationships among the three parties that are only now being unraveled by researchers.
First, the blend of chemicals released by the plant can vary subtly with the species of herbivore damaging the plant, and differs from the mixture released upon purely mechanical damage. This is important, because in order for the signal to be effective in recruiting the natural enemies of the herbivore, false alarms must be avoided. How do plants distinguish between mechanical and feeding damage? The answer lies in the presence of herbivore oral secretions, which contain a group of compounds called elicitors. If a plant surface is damaged mechanically, and an elicitor such as volicitin is applied, this will induce the same volatile response as caterpillar feeding. The presence of particular elicitors in herbivore spit is also thought to lie behind the subtle changes in volatile profile that allow highly specific natural enemies to locate their prey accurately. Interestingly, the herbivore-induced volatiles are not just released by the parts of the plant under attack, but also by undamaged leaves.
The basis of this fascinating phenomenon is the exquisitely sensitive molecular recognition of semiochemicals by the insect predators. Indeed, one of the problems faced by researchers in this field is the fact that the insects' sensitivity to the semiochemicals is substantially greater than that of detection techniques employed by scientists. Over the last decade, as the sensitivity of detection equipment has increased, so has the list of components in volatile blend. One of the puzzles troubling researchers is why, of the 100 or so volatile chemicals currently known to be released by the plant, just a handful are used by the natural enemies to locate their hosts. It is also remarkable that of the 30 000 isoprenoids made by plants, quite a restricted common group seems to be used by a large number of taxonomically unrelated species in these interactions. Work is underway to identify the biologically relevant signals, and some success has already been achieved with synthetic odour blends that have proved attractive to predators and parasitoids.
Future challenges abound. The hope is that by understanding these systems, will we be able to make a shift in pest management practices from an approach based on pesticides to one that promotes effective biological control of insect pests of agricultural crops.
Jamie Goode (Editor, Novartis Foundation)
[Insect–plant interactions and induced plant defence (including the published papers and all the discussions from this symposium) is published in June 1999 by John Wiley & Sons, Chichester.]
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African Cereal Stem Borers: Natural Enemies and Control. Edited by A Polaszek, CAB BIOSCIENCE UK Centre, c/o Entomology Department, Natural History Museum, London, SW7 5BD, UK.
TI: Identification of semiochemicals released during aphid feeding that attract parasitoid Aphidius ervi.
AU: Du YongJun\ Poppy, G. M.\ Powell, W.\ Pickett, J. A.\ Wadhams, L. J.\ Woodcock, C. M.
JN: Journal of Chemical Ecology
YR: 1998
VL: 24
NO: 8
PP: 1355-1368
LA: En
MS: 47 ref.
AA: Entomology and Nematology Department, IACR-Rothamsted, Harpenden, Herts AL5 2JQ, UK.
AB: Herbivore-induced release of plant volatiles mediating the foraging behaviour of the aphid parasitoid Aphidius ervi was investigated using Acyrthosiphon pisum, feeding on broad bean, Vicia faba [faba beans]. Behavioural responses were studied using an olfactometer
and a wind tunnel. Volatiles obtained by air entrainment of aphid-infested plants were more attractive to A. ervi than those from uninfested plants, in both behavioural bioassays. Gas chromatography-electroantennograms (GC-EAG) of both extracts showed a number of peaks associated with responses by A. ervi, but with some differences between extracts. Compounds giving these peaks were tentatively identified by gas chromatography-mass spectrometry (GC-MS) and confirmed by comparison with authentic samples on GC,
using two columns of different polarity. The activity of pure compounds was further investigated by EAG and wind tunnel assays. Results showed that of the compounds tested, 6-methyl-5-hepten-2-one was the most attractive for A. ervi females, with linalool, (Z)-3-hexen-1-yl acetate, (E)-ß-ocimene, (Z)-3-hexen-1-ol, and (E)-ß-farnesene all eliciting significantly more oriented flight behaviour than a solvent
control. Foraging experience significantly increased parasitoid responses to these compounds, with the exception of (E)-ß-farnesene. Time-course GC analysis showed that feeding of A. pisum on V. faba induced or increased the release of several compounds. Release of two of these compounds (6-methyl-5-hepten-2-one and geranic acid) was not induced by the nonhost black bean aphid, Aphis fabae. During the analysis period,
production of (E)-ß-ocimene remained constant, but 6-methyl-5-hepten-2-one, linalool, geranic acid, and (E)-ß-farnesene appeared during the first day after A. pisum infestation and increased in concentration with increasing time of aphid feeding.
DE: Homoptera\Aphididae\Hymenoptera\Braconidae\semiochemicals\Acyrthosiphon
pisum\Aphidius ervi\Vicia faba\Aphidius\parasitoids\Aphis\animal behaviour\linalool\Vicia\volatile compounds\hosts\insect
attractants\6-methyl-5-hepten-2-one\(Z)-3-hexen-1-yl acetate\(E)-beta-ocimene\(Z)-3-hexen-1-ol\(E)-beta-farnesene\geranic acid\Aphis fabae\faba beans
AN: 0E08611625
TI: Defensive role of Allium sulfur volatiles against the insects.
FT: Composes soufres des Allium et lutte contre les insectes.
CT: Colloque internationale 'Les substances naturelles secretes chez les vegetaux: roles ecologique, physiologique et applique', Paris, France, 11-13 janvier 1995.
AU: Thibout, E.\ Auger, J.
JN: Acta Botanica Gallica
YR: 1997
VL: 144
NO: 4
PP: 419-426
LA: Fr
LS: en
MS: 31 ref.
AA: IRBI, URA CNRS 1298, Faculte des Sciences, Parc Grandmont, F-37200 Tours, France.
AB: Sulfur volatiles emitted by Allium plants attract the insects which develop in contact with these plants. However, the sulfur volatiles can be perceived by other organisms living in the vicinity or far from this biocenosis and can have negative effects on them. Several
works have shown that Allium or extracts are active against many insects. The present knowledge on odour emission of Allium was summarized to investigate the active compounds. Two kinds of action were shown: the first is behavioural (repellency and antifeedancy), and the second physiological (effects on development and insecticidal effects). Many insect species are affected (predators, parasitoids, haematophages, specialist and generalist phytophages, folivores and seminovores). The properties of the sulfur volatiles can be used to control insect populations in an environmentally friendly manner.
DE: behaviour\toxicity\sulfur\insects\Allium\volatile compounds\effects\extracts\parasitoids\predators\properties\botanica l insecticides\insect pests\repellents\antifeedants\semiochemicals\conferences
AN: 0E08610567
TI: The effect of complete versus incomplete information on odour discrimination in a parasitic wasp.
AU: Vet, L. E. M.\ Jong, A. G. de\ Franchi, E.\ Papaj, D. R.
JN: Animal Behaviour
YR: 1998
VL: 55
NO: 5
PP: 1271-1279
LA: En
MS: 27 ref.
AA: Department of Entomology, Wageningen Agricultural University, PO Box 8031, NL-6700, EH Wageningen, Netherlands.
AB: Laboratory studies were conducted to determine the function of learning in the eucoilid parasitoid Leptopilina heterotoma by examining the discrimination of odour stimuli used in foraging for a host. To optimize the rate of host encounters, parasitoids are expected to assess the extent to which variation in host substrate odours is reliably associated with the variation in the presence of hosts, i.e., substrate profitability. It was hypothesized that foraging decisions were based on the completeness of information available about differences in substrate profitability. The results showed that discrimination and non-discrimination of odour stimuli were dynamic behavioural decisions related to the degree of substrate variation and to the parasitoids 'informational' state. In wind tunnel studies, females learned to discriminate between odours from substrates that were qualitatively different (apple, pear or yeast with different C&(6) compounds added). Parasitoids did not discriminate when differences were small (e.g. between odours from 2 apple varieties or between yeast patches with different concentrations of ethyl acetate), unless unrewarding experiences indicated the absence of a host. The authors suggest that non-discrimination between odour stimuli is a functional decision by L. heterotoma.
DE: host-seeking behaviour\parasitoids\natural enemies\Leptopilina heterotoma\odours\apples\pears\Malus\Pyrus\yeasts\biological control agents\plant extracts\attractants\chemical ecology\semiochemicals
AN: 0E08609349\7E01902708
TI: Herbivore-infested plants selectively attract parasitoids.
AU: Moraes, C. M. de\ Lewis, W. J.\ Pare, P. W.\ Alborn, H. T.\ Tumlinson, J. H.
JN: Nature (London)
YR: 1998
VL: 393
NO: 6685
PP: 570-573
LA: En
MS: 19 ref.
AA: Department of Entomology, University of Georgia, Coastal Plain Experiment Station, PO Box 748, Tifton, Georgia 31793, USA.
AB: In response to insect herbivory, plants synthesize and emit blends of volatile compounds from their damaged and undamaged tissues which act as important host-location cues for parasitoids. Chemical and behavioural assays were used to show that these plant emissions can transmit herbivore-specific information that is detectable by parasitoids. Tobacco, cotton and maize plants each produced distinct volatile blends in response to damage by two closely related pest species, Heliothis virescens and Helicoverpa zea. The specialist braconid parasitoid Cardiochiles nigriceps exploits these differences to distinguish infestation by its host, Heliothis virescens, from that by Helicoverpa zea. The production by phylogenetically diverse plant species and the exploitation by parasitoids of highly specific chemical signals, keyed to individual herbivore species, indicated that the interaction between plants and natural enemies of the herbivores that attack them is more sophisticated than previously realized.
DE: insect pests\plant pests\natural enemies\beneficial insects\parasitoids\hosts\chemical ecology\tobacco\maize\cotton\Nicotiana\Zea mays\Gossypium hirsutum\semiochemicals\Heliothis virescens\Helicoverpa zea\Cardiochiles nigriceps\interactions\host-seeking behaviour
AN: 7E01902013\0E08609334\6P01402920
TI: Strategies involved in the location of hosts by the parasitoid Aphidius ervi Haliday (Hymenoptera: Braconidae: Aphidiinae).
AU: Powell, W.\ Pennacchio, F.\ Poppy, G. M.\ Tremblay, E.
JN: Biological Control
YR: 1998
VL: 11
NO: 2
PP: 104-112
LA: En
MS: 43 ref.
AA: Entomology and Nematology Department, IACR-Rothamsted, Harpenden, UK.
AB: The use of semiochemical and physical cues by Aphidius ervi to locate and recognize its main host, Acyrthosiphon pisum, is discussed under the following headings: long-range cues; short-range and contact cues; and learning. A parasitoid manipulation strategy, based on female responses to synthetic aphid sex pheromones, is also discussed.
DE: Aphidius ervi\Acyrthosiphon pisum\hosts\parasitoids\behaviour\host-seeking behaviour\Aphididae\semiochemicals\sex pheromones
AN: 0E08608256
TI: Specificity of systemically released cotton volatiles as attractants for specialist and generalist parasitic wasps.
AU: Rose, U. S. R.\ Lewis, W. J.\ Tumlinson, J. H.
JN: Journal of Chemical Ecology
YR: 1998
VL: 24
NO: 2
PP: 303-319
LA: En
MS: 35 ref.
AA: Center for Medical, Agricultural and Veterinary Entomology, Agricultural Research Service, U.S. Department of Agriculture, Gainesville, Florida 32608, USA.
AB: Cotton plants under herbivore attack release volatile semiochemicals that attract natural enemies of the herbivores to the damaged plant. The volatiles released in response to herbivory are not only released from the damaged leaves but from the entire cotton plant. Cotton plants that released myrcene, (Z)-3-hexenyl acetate, (E)-ß-ocimene, linalool, (E)-4,8-dimethyl-1,3,7-nonatriene, (E)-ß-farnesene, and (E, E)-4,8,12-trimethyl-1,3,7, 11-tridecatetraene systemically from undamaged leaves of larvae damaged plants were attractive to the generalist parasitoid Cotesia marginiventris and the specialist parasitoid Microplitis croceipes. Plants from which the larvae damaged leaves were removed and that released those compounds systemically were significantly preferred over undamaged control plants in two-choice experiments in a flight tunnel. Artificially damaged cotton plants that released green leafy volatiles and constitutive terpenoids were less attractive for M. croceipes and C. marginiventris. Only C. marginiventris preferred artificially damaged plants over undamaged control plants, whereas M. croceipes showed no preference. The apparent lack of specificity of systemically released compounds in response to different herbivores feeding on the lower leaves is discussed.
DE: Vespidae\Gossypium hirsutum\cotton\parasitoids\Microplitis croceipes\Cotesia marginiventris\cotton\attractants\Gossypium\volatile compounds\larvae\Lepidoptera\Cotesia\feeding\herbivores\linalool\Mic roplitis\myrcene\responses\semiochemicals\terpenoids\plant extracts
AN: 0E08606501\7E01902318
TI: Field response of southern pine beetle parasitoids to some natural attractants.
AU: Sullivan, B. T.\ Berisford, C. W.\ Dalusky, M. J.
JN: Journal of Chemical Ecology
YR: 1997
VL: 23
NO: 3
PP: 837-856
LA: En
MS: 37 ref.
AA: Department of Entomology, University of Georgia, Athens, Georgia 30602, USA.
AB: Studies were performed to isolate and identify semiochemicals that mediate location of host-infested trees by parasitoids of Dendroctonus frontalis. Bark or bolts removed from pines (Pinus) infested with beetle attracted significant numbers of the hymenopterous parasitoids Spathius pallidus and Roptrocerus xylophagorum to sticky traps placed in an active beetle infestation. Traps baited with the water distillate of D. frontalis brood-infested bark also attracted both species of parasitoids. In contrast, a synthetic bait composed of 18 compounds identified from the headspace volatiles of attractive bark failed to trap parasitoids. The oxygenated and hydrocarbon components of the bark distillate were partitioned by silica gel liquid chromatography, and the resulting two fractions were tested in the field in the USA. Parasitoid attraction was greatest when both fractions were released from traps simultaneously. The hydrocarbon fraction, which failed to attract parasitoids, enhanced the weak attractiveness of the oxygenated fraction. Hence, it appears that no single compound is responsible for mediating D. frontalis parasitoid host-tree location and that both oxygenated and hydrocarbon semiochemicals are involved in this process.
DE: Dendroctonus frontalis\Roptrocerus xylophagorum\terpenoids\fractionation\terpenoids\parasitoids\attract ants\hosts\insect pests\plant pests\forest pests\Spathius pallidus\natural enemies\semiochemicals\Pinus
GL: USA
AN: 0E08606075\7E01902357
TI: Chemically-mediated attraction of three parasitoid species to mealybug-infested cassava leaves.
AU: Bertschy, C.\ Turlings, T. C. J.\ Bellotti, A. C.\ Dorn, S.
JN: Florida Entomologist
YR: 1997
VL: 80
NO: 3
PP: 383-395
LA: En
MS: 38 ref.
AA: Institute of Plant Sciences, Applied Entomology, ETH (Swiss Federal Institute of Technology), CH-8092 Zurich, Switzerland.
AB: It was investigated whether cassava plants that are infested by Phenacoccus herreni emit attractants for the encyrtid parasitoids Aenasius vexans, Apoanagyrus diversicornis and Acerophagus coccois. Bioassays with a Y-tube olfactometer showed for all three species that female wasps were most responsive and selective when they were 1.5-2.5 days old. Females of these age groups were used to test their ability to distinguish between the odour of plants with and without P. herreni. The wasps were offered choices between infested cassava leaves vs. healthy ones, infested leaves vs. clean air, and healthy leaves vs. clean air. A. vexans and A. diversicornis were strongly attracted to infested leaves and preferred these to healthy ones. In contrast, A. coccois was significantly attracted to either healthy or infested leaves, and did not distinguish between the two. The results suggest that A. coccois, which has the broadest known host range of the three, may be responsive only to general plant odours, while A. vexans and A. diversicornis respond more specifically to odours associated with mealybug infestation.
DE: semiochemicals\cassava\Manihot esculenta\Phenacoccus herreni\Aenasius vexans\Apoanagyrus diversicornis\Acerophagus coccois\parasitoids\natural enemies\insect pests\plant pests\attractants
AN: 0E08602582\7E01900121
TI: Aphid parasitoid responses to semiochemicals - genetic, conditioned or learnt?
AU: Poppy, G. M.\ Powell, W.\ Pennacchio, F.
JN: Entomophaga
YR: 1997
VL: 42
NO: 1/2
PP: 193-199
LA: En
LS: fr
MS: 25 ref.
AA: Dept Entomology/Nematology, IACR Rothamsted, Harpenden, Herts, UK.
AB: Parasitoid foraging behaviour is known to be influenced by interactions of genetic, physiological, environmental and experiential factors. Although the role of genetics, learning and conditioning in determining responses to foraging cues has been studied in lepidopteran parasitoids, aphid parasitoids have been less intensively researched. Using the tritrophic system, Vicia faba - Acyrthosiphon pisum - Aphidius ervi, evidence for the role of genetics and learning in parasitoid foraging is presented, and the difficulty of differentiating between genetic responses and those conditioned during parasitoid development is discussed. A. ervi responds to aphid sex pheromones both in the field and in the laboratory. Since laboratory reared individuals have never experienced sexual aphids, the response must be genetic as it cannot have been conditioned during development. An example of a response conditioned during development is the variable response of A. rhopalosiphi to different wheat cultivars depending upon host feeding. Aphid parasitoids are also adept at learning as shown by their responses to plant-derived cues which are learnt as Conditioned Stimuli (CS). Host products such as honeydew, as well as the host itself, can act as the Unconditioned Stimulus (US) in the learning process. A. ervi offers a good model for investigating the role of these factors in parasitoid foraging behaviour. The value of such research for biological control programmes involving aphid parasitoids is discussed.
DE: semiochemicals\foraging\animal behaviour\insect pests\plant pests\Vicia faba\plant extracts\faba beans\Aphidius ervi\Acyrthosiphon pisum\Aphis
fabae\interactions\Aphididae\behaviour\parasitoids\behaviour\effects \learning
AN: 0E08601112\7E01900103
TI: Responses of female Aphelinus asychis (Hymenoptera: Aphelinidae) and Aphidius matricariae (Hymenoptera: Aphidiidae) to host and plant-host odors.
AU: Farias, A. M. I. de\ Hopper, K. R.
JN: Environmental Entomology
YR: 1997
VL: 26
NO: 4
PP: 989-994
LA: En
MS: 23 ref.
AA: European Biological Control Laboratory, USDA-ARS, BP 4168 Parc Scientifique Agropolis II, 34092 Montpellier Cedex 5, France.
AB: Field surveys showed previously that mummies of Diuraphis noxia parasitized by Aphelinus asychis were 3-fold more abundant than those parasitized by Aphidius matricariae in a region where these species are endemic. A series of olfactometer experiments was carried out to test whether this difference in parasitoid abundance might arise from differences in attraction to host or host-plant odours. A 4-way olfactometer was used to measure choices among 4 odour sources (filtered air, barley (Hordeum vulgare), D. noxia, and D. noxia plus barley) and the time spent in these 4 odour fields. Field-collected and laboratory-reared A. asychis females did not move preferentially towards D. noxia or D. noxia-barley odours compared with filtered air or barley odours. This lack of preference was not affected by experience in which parasitoid females were allowed to oviposit in D. noxia on barley before being tested. However, after such experience, A. asychis females spent more time in the D. noxia-barley odour field than in the other odour fields. In contrast, naive A. matricariae females chose D. noxia-barley odours over other odours, and experienced A. matricariae females chose odours from D. noxia alone, as well as odours from barley plus D. noxia, over filtered air and barley odours. A. matricariae females spent more time in the D. noxia odour field than in the other odour fields, whether or not they were experienced with the plant-host complex. These results suggest that greater attraction to D. noxia cannot explain the greater abundance of A. asychis found on this host in the field.
DE: insect pests\plant pests\natural enemies\hordeum vulgare\Diuraphis noxia\barley\parasitoids\Aphelinus asychis\Aphidius matricariae\hosts\Hymenoptera\semiochemicals\effects\Hordeum\Hordeum \biological control
AN: 0E08601230\6T01500638\7E01900058
TI: Semiochemical-mediated location of host habitat by Apanteles carpatus (Say) (Hymenoptera: Braconidae), a parasitoid of clothes moth larvae.
AU: Takacs, S.\ Gries, G.\ Gries, R.
JN: Journal of Chemical Ecology
YR: 1997
VL: 23
NO: 2
PP: 459-472
LA: En
MS: 33 ref.
AA: Centre for Pest Management, Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada.
AB: In Y-tube olfactometer bioassays, adults of the braconid Apanteles carpatus were attracted to beaver or rabbit pelts infested with larvae of the tineid Tinea pellionella. Porapak Q-captured volatiles from a T. pellionella-infested beaver pelt were also very attractive, whereas isolated larvae or larval faeces of T. pellionella were not. Coupled gas chromatographic-electroantennographic detection (GC-EAD) analysis of the Porapak Q volatile extract revealed two compounds that elicited responses by A. carpatus antennae. Coupled GC-mass spectrometry (MS) in electron impact and chemical ionization modes of these compounds indicated, and GC-MS and GC-EAD of authentic standards confirmed, that they were nonanal and geranylacetone. While each compound singly did not attract A. carpatus, a 1:1 blend of both compounds was as attractive as the volatile extract. Because these compounds are host habitat-derived, A. carpatus must be a habitat rather than host specialist, responding to kairomonal indicators of localized and specific habitats such as animal hair or feather. The tritrophic interaction between A. carpatus, its tineid hosts and their animal-derived habitats is similar to the well-studied relationship between parasitoids of insect herbivores and their host plant habitats.
DE: insect pests\natural enemies\beneficial insects\biological control agents\analytical methods\antennae\sense organs\electroantennograms\gas chromatography\mass spectrometry\nonanal\geranylacetone\semiochemicals\Apanteles\Tinea pellionella\parasitoids\Apanteles carpatus\hosts\behaviour\host-seeking behaviour\kairomones\attractants
AN: 0E08600321\7E01900332
TI: Response of the melon fly parasitoid Psyttalia fletcheri (Hymenoptera: Braconidae) to host-habitat stimuli.
AU: Messing, R. H.\ Klungness, L. M.\ Jang, E. B.\ Nishijima, K. A.
JN: Journal of Insect Behavior
YR: 1996
VL: 9
NO: 6
PP: 933-945
LA: En
MS: 12 ref.
AA: University of Hawaii, Department of Entomology, Kauai Research Station, Kapaa, Hawaii 96746, USA.
AB: Cohorts of mass-reared adult females of Psyttalia fletcheri [Opius fletcheri], a parasitoid of Bactrocera cucurbitae, were exposed to host plant stimuli in a laminar airflow wind tunnel to analyse the cues used in host-habitat finding. Parasitoids hovered twice as frequently around plastic zucchini models emitting fresh cucumber odour as around models emitting clean air. The odour of decaying pumpkin was even more attractive, resulting in a <more than>10-fold increase in hovering, a 50-fold increase in landing, and a 150-fold increase in host-searching and probing behaviours compared to clean air. Fresh cucumber leaf odours were not attractive to the parasitoids, but decomposing leaves elicited a strong increase in hovering, landing, and searching behaviours. Plastic leaves which visually simulated cucurbit foliage did not in themselves significantly alter orientation behaviours, but the combination of leaf visual stimuli plus decaying leaf odours caused strong increases in hovering, landing and searching. Fresh pumpkin odour and the odour of yeast-inoculated pumpkin were not as attractive to parasitoids as decaying leaf odours. Yeast isolated from decaying pumpkin and cultured on various sterile media were not substantially more attractive than clean air.
DE: natural enemies\beneficial insects\biological control agents\Cucumis sativus\Cucurbita\semiochemicals\Opius\Opius fletcheri\behaviour\host-seeking behaviour\Bactrocera cucurbitae\parasitoids\hosts\cucumbers\pumpkins\odours\effects\plant extracts
AN: 0E08508306
TI: Movement and response to semiochemicals by parasitoids of Plathypena scabra (Lepidoptera: Noctuidae).
AU: Baur, M. E.\ Yeargan, K. V.
JN: Journal of the Kansas Entomological Society
YR: 1996
VL: 69
NO: 2
PP: 122-132
LA: En
MS: 28 ref.
AA: Department of Entomology, University of Kentucky, Lexington, KY 40546, USA.
AB: On legumes, Plathypena scabra [Hypena scabra] is parasitized by Cotesia marginiventris, Diolcogaster facetosa and Aleiodes nolophanae; these primary parasitoids are hyperparasitized by Mesochorus discitergus. D. facetosa and A. nolophanae are host-specialists and C. marginiventris and M. discitergus are host-generalists. In a first experiment, the hypothesis was tested that the specialists are more vagile than the generalists by placing trap plots consisting of either the native tick-trefoil (Desmodium paniculatum) or soyabean (Glycine max) between and within legume fields. D. facetosa parasitism of H. scabra placed in trap plots outside legume fields was high, while parasitism by C. marginiventris was low in those plots. This result suggested higher vagility of the host-specialist compared with the host-generalist. In addition, tick-trefoil and soyabean plots were equally apparent to both parasitoid species. In a second experiment, the hypothesis was tested that generalist parasitoids respond to a broader range of volatiles than specialist parasitoids. The flight response of the 4 parasitoid species to volatiles was measured in a flight tunnel in no-choice assays. The 2 test odours used were green leaf volatiles released from soyabeans damaged mechanically, and the plant-host complex that included soyabeans fed upon by H. scabra larvae and larvae plus associated kairomones. All 4 parasitoid species initiated upwind flight to green leaf volatiles, but the host-specialist, A. nolophanae, responded more strongly to the plant-host complex than to green leaf volatiles. Some upwind flights in the absence of volatile release were observed, but they were too few to explain the response of the parasitoids to green leaf volatiles or the plant-host complex.
DE: semiochemicals\insect pests\plant pests\Glycine max\flight\natural enemies\hyperparasitoids\soyabeans\Desmodium paniculatum\Hypena scabra\food plants\parasitoids\Cotesia marginiventris\Diolcogaster facetosa\Aleiodes nolophanae\hosts\Hymenoptera\parasitoids\Mesochorus discitergus\behaviour\movement\parasitoids\parasitoids\parasitoids\p arasitoids\parasitoids
AN: 0E08503276\7N02000677\7E01800832
TI: Semiochemicals in host and mate finding behavior of Macrocentrus grandii Goidanich (Hymenoptera; Braconidae).
CT: Symposium: Insect behavioural ecology - '95.
AU: Jones, R. L.
JN: Florida Entomologist
YR: 1996
VL: 79
NO: 2
PP: 104-108
LA: En
LS: es
MS: 11 ref.
AA: Office of the Dean for Research, University of Florida, IFAS, Gainesville, FL 32611, USA.
AB: Naive females of Macrocentrus grandii, a parasitoid of Ostrinia nubilalis (ECB) were attracted to some, but not all, host plant species of the latter; attraction being exceptionally strong for Zea mays, progressively weaker for potato, snapbean [Phaseolus vulgaris] and pepper [Capsicum], neutral for sunflower, with soyabean being slightly repellent. Also, extracts of volatiles from soyabean were repellent. The percent of females that responded to a given ECB host plant increased progressively with age of females to a maximum at 8 days. When various plant species were damaged by feeding activity of ECB, they became highly attractive to M. grandii females, and, subsequently, these experienced females were attracted to undamaged plants, even of plants species that were not attractive to naive females. Responsiveness of females to all plant species increased as a result of experience with ECB-damaged plant specimens of host species. Such experience with ECB-damaged potato increased attraction of females to sunflower by 4-fold, while experience with ECB-damaged sunflower increased attraction to potato by 2-fold. Loss of memory in females of experience with ECB-damaged plants progressed with time and was total by the ninth day. Memory was induced primarily by frass, but not because frass was derived from a particular plant species. Male M. grandii were not attracted to any host plant. Female M. grandii emit a series of 9, 13 dienes of odd-numbered 27-41 carbon atom chains, and these, when oxidized by air, produced Z-4-tridencenal, the active volatile of the pheromone. The latter when emitted at 50 ng per hr proved to be a very effective lure. Further, we found that this aldehyde is synergized significantly by the lactone, (3S,5R,6S)-3, 5-dimethyl-6-(methylethyl)-3,4,5,6-tetrahydropyran-2-one. It is noteworthy that this lactone by itself is highly attractive when 1 to 500 ng are applied to the source. The lactone is produced by the mandibular gland of both males and females. Possibly the diene/aldehyde has arisen as an important intermediary evolutionary step, in a process wherein opportunistic males that recognize volatile chemicals unique to the female may have been selected. Natural selection then would favour females that produce more and more of the attractant precursor - a process that could lead eventually to selection for specialized cells and a pheromone gland.
DE: insect attractants\Macrocentrus\animal behaviour\semiochemicals\Solanum tuberosum\Zea mays\conferences\Insect behavioural ecology\Macrocentrus grandii\hosts\Ostrinia nubilalis\parasitoids\potatoes\maize\Phaseolus vulgaris\Capsicum\food plants\behaviour\mating behaviour\sex pheromones\pheromones\(3S,5R,6S)-3,5-Dimethyl-6-(methylethyl)-3,4,5, 6-tetrahydropyran-2-one\pheromones\behaviour\pheromones\pheromones
AN: 0E08502209\7E01800751
TI: The influence of the host plant of diamond-back moth (Plutella xylostella) on the plant preferences of its parasitoid Cotesia plutellae in Sri Lanka.
AU: Bogahawatte, C. N. L.\ Emden, H. F. van
JN: Physiological Entomology
YR: 1996
VL: 21
NO: 2
PP: 93-96
LA: En
MS: 28 ref.
AA: Department of Horticulture and Landscape, School of Plant Sciences, University of Reading, Whiteknights, Reading, Berks. RG6 6AS, UK.
AB: In Y-tube olfactometer tests, females of the braconid Cotesia plutellae, a major parasitoid of Plutella xylostella in southeast Asia, preferred the odour of the brassica-type (Blue Lake cabbage) on which they had developed. Such plants were even preferred to the odour of larvae-infested and damaged leaves of another brassica (Early Phenomenal cauliflower). However, within 1 brassica type, the odour of larvae-infested leaves was preferred to that of uninfested and undamaged leaves. Odours of both Blue Lake and Early Phenomenal were preferred to the control odour (water). However, following the transfer of the parasitoid from Blue Lake to another cabbage (Brunswick) for 1 generation, females no longer distinguished between Blue Lake and Early Phenomenal.
DE: insect pests\plant pests\Brassica\leafy vegetables\natural enemies\beneficial insects\biological control agents\olfactometers\odour emission\Sri Lanka\Cotesia plutellae\biology\behaviour\Plutella xylostella\hosts\parasitoids\cabbages\cauliflowers\odours\effects\se miochemicals\attractants
GL: Sri Lanka
AN: 0E08411719\7E01702906
TI: A caffeic acid ester mediates host recognition by a parasitic wasp.
AU: Hare, J. D.\ Millar, J. G.\ Luck, R. F.
JN: Naturwissenschaften
YR: 1993
VL: 80
NO: 2
PP: 92-94
LA: En
MS: 15 ref.
AA: Department of Entomology, University of California, Riverside, CA 92521, USA.
AB: It was shown in laboratory studies that O-caffeoyltyrosine (a previously unknown ester of caffeic acid and tyrosine) is a major component of the kairomone of the diaspidid Aonidiella aurantii and that the parasitoid Aphytis melinus responds quantitatively to its concn. The dose eliciting peak activity by the aphelinid corresponded with the amount observed in scale covers when Aonidiella aurantii was most suitable for parasitism by Aphytis melinus.
DE: insects\Hemiptera\Diaspididae\Hymenoptera\Aphelinidae\natural enemies\attractants\tyrosine\caffeic acid\semiochemicals\Aonidiella aurantii\Aphytis melinus\hosts\parasitoids\caffeoyltyrosine\kairomones\biology\behavi our
AN: 0E08307628\7E01602174
TI: Comparative headspace analysis of cabbage plants damaged by two species of Pieris caterpillars: consequences for in-flight host location by Cotesia parasitoids.
AU: Blaakmeer, A.\ Geervliet, J. B. F.\ Loon, J. J. A. van\ Posthumus, M. A.\ Beek, T. A. van\ Groot, A. de
JN: Entomologia Experimentalis et Applicata
YR: 1994
VL: 73
NO: 2
PP: 175-182
LA: En
MS: 39 ref.
AA: Department of Organic Chemistry, Phytochemical Section, Agricultural University, Dreijenplein 8, 6703 HB Wageningen, Netherlands.
AB: The headspace composition collected from intact Brassica oleracea var. gemmifera (Brussels sprouts) plants infested with either 1st-instar larvae of Pieris brassicae or P. rapae was determined using GC-MS. Twenty-one volatiles were identified in the headspace of intact plants. Twenty-two volatiles were identified in the headspace of plants infested by larvae of P. brassicae, 2 of which, (Z)-3-hexenyl butyrate and (Z)-3-hexenyl isovalerate, were not detected in the headspace of either intact plants or plants damaged by P. rapae. In the headspace of the latter, 21 compounds were identified, all of which were also produced by intact plants. No significant quantitative differences were found between the headspace composition of the plants damaged by either species. Major differences between intact and damaged plants in contribution to the headspace profile were revealed for hexyl acetate, (Z)-3-hexenyl acetate, myrcene, sabinene and 1,8-cineole. The larval endoparasitoid Cotesia glomerata was attracted by the volatiles emanating from Brussels sprouts damaged by 1st-instar larvae of P. brassicae. C. rubecula, a specialized larval endoparasitoid of P. rapae, was attracted by the volatiles released from the Brussels sprouts-P. rapae plant-host complex. This showed that Brussels sprouts kept under the conditions of headspace collection produced attractive volatiles for both parasitoids.
DE: insect pests\plant pests\Pieridae\Lepidoptera\leafy vegetables\natural enemies\Braconidae\Hymenoptera\biological control\biological control agents\Brassica oleracea var. gemmifera\allelochemicals\Pieris (lepidoptera)\Brussels sprouts\Pieris brassicae\Pieris rapae\pieris (lepidoptera)\Cotesia glomerata\Cotesia rubecula\biology\behaviour\hosts\parasitoids\odours\effects\Cotesia\ semiochemicals\attractants\Cotesia\pieris (lepidoptera)\Cotesia
AN: 0E08306582\7E01601604
TI: Influence of pre-emergence experience on response to host and host plant odours in the larval parasitoid Eupelmus vuilleti.
AU: Cortesero, A. M.\ Monge, J. P.
JN: Entomologia Experimentalis et Applicata
YR: 1994
VL: 72
NO: 3
PP: 281-288
LA: En
MS: 21 ref.
AA: Institut de Biocenotique Experimentale des Agrosystemes, U.R.A. C.N.R.S. 1298, Avenue Monge, Parc de Grandmont, 37200 Tours, France.
AB: The response of Eupelmus vuilleti to different host and plant species odours was investigated. This hymenopteran is a solitary ectoparasitoid of several species of bruchid developing inside Leguminosae seeds. The locomotor behaviour of females reared on larvae of Bruchidius atrolineatus developing in seeds of Vigna unguiculata [cowpeas] was analysed using a tubular olfactometer. Females showed a specific sensitivity to the semiochemicals emanating from the host and the seed species on which they had developed. Odours from seeds of cowpeas were attractive to the parasitoid and stimulated their locomotor activity. Odours from seeds of V. radiata had no effect on the locomotor behaviour. Odours from larvae of B. atrolineatus were attractive to the females whereas odours from Callosobruchus maculatus, another bruchid species, had no effect. By isolating the females from the seed and the host at different developmental stages, the specific sensitivity observed resulted from an early adult learning. This learning, which occurred before the emergence from the seed while the imago was in the larval chamber of its host, was dependent on contact with the seed and the host larval remains.
DE: insect pests\plant pests\Coleoptera\Bruchidae\natural enemies\beneficial insects\Eupelmidae\Hymenoptera\seeds\Vigna unguiculata\grain legumes\semiochemicals\olfactometers\animal behaviour\Fabaceae\movement\host-seeking behaviour\Vigna radiata\cowpeas\odours\effects\Eupelmus vuilleti\biology\behaviour\Bruchidius atrolineatus\hosts\parasitoids\behaviour
AN: 0E08304482\7E01601323
TI: Plant-natural enemy association in the tritrophic system Cotesia rubecula-Pieris rapae-Brassicaceae (Cruciferae): II. Preference of C. rubecula for landing and searching.
AU: Agelopoulos, N. G.\ Keller, M. A.
JN: Journal of Chemical Ecology
YR: 1994
VL: 20
NO: 7
PP: 1735-1748
LA: En
MS: 21 ref.
AA: Department of Crop Protection, Waite Campus, University of Adelaide, Glen Osmond, SA 5064, Australia.
AB: The responses of the parasitoid Cotesia rubecula to cabbages with different types of damage were recorded during a series of choice tests. To determine if flying C. rubecula could discriminate differences in the blend of volatiles emitted by cabbages damaged by different causes and how plant volatiles released from a distant source affected the searching behaviour of C. rubecula once searching on a plant, the braconids were presented with a choice of plants located one behind the other, separated by a distance of 15 cm. The sources of damage were cabbage damaged by the host Pieris rapae, by a nonhost lepidopteran, Plutella xylostella, by a nonhost, noninsect herbivore (the snail Helix aspersa), and by mechanical means. The results showed that the site of first landing and the time spent searching on the leaves was influenced by the type of damage inflicted on plants. Braconids preferred to land on cabbages damaged by host and nonhost species of Lepidoptera, to those damaged by snails and mechanical means. No preference was observed for first landing between cabbages damaged by the 2 species of Lepidoptera, or between cabbages damaged by snails and mechanical means. Cabbage damaged by Pieris rapae was searched most intensively, followed by cabbage damaged by Plutella xylostella, cabbage damaged by snails and cabbage damaged by mechanical means. C. rubecula differentiated between the volatile blends emitted by differently damaged cabbages, and was attracted to volatiles related to recent lepidopteran damage. Braconids searched longer on freshly damaged leaves than on leaves with older damage.
DE: insect pests\Pieridae\Plutellidae\Braconidae\Hymenoptera\biological control agents\natural enemies\leafy vegetables\Brassica\chemical ecology\snails\Helicidae\Mollusca\damage\plant pests\Cotesia rubecula\biology\behaviour\semiochemicals\attractants\cabbages\Helix aspersa\Pieris brassicae\Plutella xylostella\pests\Lepidoptera\extracts\plant extracts\Gastropoda\parasitoids\hosts
AN: 0E08211004\7E01600543
TI: Plant-natural enemy association in the tritrophic system, Cotesia rubecula-Pieris rapae - Brassicaceae (Cruciferae): I. sources of infochemicals.
AU: Agelopoulos, N. G.\ Keller, M. A.
JN: Journal of Chemical Ecology
YR: 1994
VL: 20
NO: 7
PP: 1725-1734
LA: En
MS: 28 ref.
AA: Department of Crop Protection, Waite Campus, University of Adelaide, Glen Osmond, SA 5064, Australia.
AB: The role of airborne infochemicals in host selection by the parasitoid Cotesia rubecula was examined in a wind tunnel. To elucidate the role of volatile chemicals in attracting C. rubecula to cabbage infested by the host (Pieris rapae), the potential sources of volatiles related to P. rapae infestation on cabbage were tested individually. The responses of females to nonhost plant species, bean (Phaseolus vulgaris) and geranium (Geranium molle), as well as to frass of a nonhost lepidopteran (Plutella xylostella), were also examined. C. rubecula was attracted to cabbage previously infested by Pieris rapae, and to frass and regurgitate of P. rapae. No attraction was observed to larvae of P. rapae alone. Females were also attracted to mechanically damaged cabbage, cabbage previously infested by Plutella xylostella and cabbage previously infested by snails (a nonhost, noninsect herbivore). Intact cabbage, Phaseolus vulgaris and G. molle elicited no attraction. A low frequency of attraction was observed to mechanically damaged P. vulgaris and G. molle. Attraction was also observed to frass of Plutella xylostella. Volatiles from cabbage related to damage, and volatiles from frass and regurgitate of the host seemed to play an important role in guiding C. rubecula to plants infested by its host.
DE: insect pests\Pieridae\Plutellidae\insect pests\leafy vegetables\Brassica\grain legumes\natural enemies\biological control agents\snails\Gastropoda\pests\chemical ecology\Cotesia rubecula\Phaseolus vulgaris\Geranium molle\cabbages\extracts\attractants\plant extracts\Plutella xylostella\Pieris brassicae\hosts\Lepidoptera\parasitoids\biology\behaviour\semiochemi cals
AN: 0E08210711\7E01600542
TI: Natural and synthetic oviposition stimulants for Catolaccus grandis (Burks) females.
AU: Guerra, A. A.\ Martinez, S.\ Rio, H. del
JN: Journal of Chemical Ecology
YR: 1994
VL: 20
NO: 7
PP: 1583-1594
LA: En
MS: 22 ref.
AA: USDA, ARS, BCPRU 2413 E. Highway 83 Weslaco, TX 78596, USA.
AB: Oviposition behaviour was elicited in the pteromalid parasitoid Catolaccus grandis, an ectoparasitoid of the Anthonomus grandis, by freshly cut cotton bolls or smears of extracts prepared with A. grandis-damaged or undamaged cotton-boll tissues. Oviposition behaviour was also elicited in females of C. grandis by smears made with n-pentane, n-hexane, n-heptane and isooctane. This is the first report of oviposition behaviour elicited for any parasitoid by these short-chain saturated hydrocarbons (alkanes), introducing a new concept on the chemical mediation of parasitoid behaviour during host selection. Oviposition behaviour was also elicited in females of C. grandis by volatiles emanating from an artificial diet devoid of insect components that was specifically developed for the in vitro rearing of ectoparasitoids. The possible use of a synergistic combination of n-hexane and diet to optimize the mechanized production of noncontaminated eggs is also discussed.
DE: Pteromalidae\Hymenoptera\biological control agents\natural enemies\oviposition\reproduction\fibre plants\insect pests\Coleoptera\Curculionidae\chemical ecology\synthetic diets\kairomones\semiochemicals\eggs\plant pests\odours\Catolaccus grandis\biology\behaviour\Anthonomus grandis\hosts\parasitoids\cotton\extracts\oviposition stimulants\plant extracts\alkanes\n-Pentane\n-Hexane\n-Heptane\isooctane\effects\diet s\diets\rearing techniques\diets
AN: 0E08211237\7E01600540
TI: Larval secretion and food odors affect orientation in female Plodia interpunctella.
AU: Phillips, T. W.\ Strand, M. R.
JN: Entomologia Experimentalis et Applicata
YR: 1994
VL: 71
NO: 3
PP: 185-192
LA: En
MS: 29 ref.
AA: USDA ARS Stored Product Insect Research Unit, University of Wisconsin, Madison, WI 53706, USA.
AB: Substrates contaminated by wandering 5th-instar larvae of Plodia interpunctella elicited oviposition by conspecific females, and larval rearing diet enhanced oviposition and also induced upwind flight. Two-choice oviposition assays determined that 4-day-old gravid females of P. interpunctella preferred to lay eggs on dishes containing cornmeal [maize meal]-based rearing diet compared with empty dishes. Pieces of cheesecloth contaminated by 5th-instar larvae elicited more oviposition than untreated cheesecloth or dishes with food. The combination of larval contamination and food was preferred over food only, or larval contamination only in both 2- and 4-choice experiments. The factor(s) in larval contamination responsible for eliciting oviposition in females was extracted in hexane, confirming that organic semiochemicals were responsible for the effects. The oviposition-eliciting activity of larval contamination was retained on cheesecloth for up to 30 days following exposure to larvae, suggesting the semiochemical component was stable and of low relative volatility. In 2-choice windtunnel bioassays, females of P. interpunctella initiated flight only when rearing food was present in one of the treatments, and they displayed the highest landing responses to a combination of larval contamination and food. Earlier work on P. interpunctella and related pyralid species has shown that larval contamination due to secretions from the mandibular glands acted as both a spacing pheromone for wandering larvae and as a kairomone for host-seeking parasitoid wasps. The present study suggested that the same or a similar secretion acts as an oviposition-eliciting pheromone for conspecific females.
DE: insect pests\Lepidoptera\Pyralidae\oviposition\pheromones\reproduction\flig ht\secretions\kairomones\parasitoids\natural enemies\glands\diets\eggs\Plodia interpunctella\biology\behaviour\semiochemicals\effects
AN: 0E08207781\7H00502253
TI: Semiochemically mediated foraging behavior in beneficial parasitic insect
AU: Tumlinson, J. H.\ Turlings, T. C. J.\ Lewis, W. J.
JN: Archives of Insect Biochemistry and Physiology
YR: 1993
VL: 22
NO: 3-4
PP: 385-391
LA: En
MS: 24 ref.
AA: Insect Attractants, Behavior, and Basic Biology Research Laboratory, ARS, USDA, Gainesville, FL, USA.
AB: Chemical cues enable female parasitoid wasps [Hymenoptera] to locate the eggs, larvae or other life stages of the insects in, or on which they place their eggs. These chemical signals, or semiochemicals, may be produced by the hosts and/or by the plants on which the hosts feed. The composition of the chemical signal often differs with different species of hosts or with different plants. New evidence suggests that the Hymenoptera exploit semiochemicals emitted by plants in response to insect herbivore feeding, and learn to respond to the different blends of chemicals that indicate the location of their hosts; they can be trained to respond to a specific odour blend. Thus, it may be possible to increase their effectiveness for biological control by conditioning them, prior to their release, to search for a target pest in a particular crop. This paper was presented at the United States-Israel BARD Workshop on New Targets for Insect Management in Crop Protection held on 5-10 October 1991 in Israel.
DE: Natural enemies\Beneficial insects\Parasitoids\Biological control\Insect pests\Eggs\Larvae\Hymenoptera\biology\behaviour\Semiochemicals\attra ctants\Conferences\United States-Israel BARD Workshop\New targets for insect management in crop protection
AN: 0E08206331\7E01502308
TI: Electroantennogram responses of the southern pine beetle parasitoid Coeloides pissodis (Ashmead) (Hym., Braconidae) to potential semiochemicals.
AU: Salom, S. M.\ Ascoli-Christensen, A.\ Birgersson, G.\ Payne, T. L.\ Berisford, C. W.
JN: Journal of Applied Entomology
YR: 1992
VL: 114
NO: 5
PP: 472-479
LA: En
MS: 27 ref.
AA: Virginia Polytechnic Institute & State University, Blacksburg, VA, USA.
AB: In studies using the electroantennogram (EAG) technique, bark beetle- and tree-produced semiochemicals were presented to Coeloides pissodis, a larval parasitoid of Dendroctonus frontalis. In a preliminary study, 20 test compounds and a standard mixture of oxygenated monoterpenes were presented individually as serial dilutions to the parasitoids. The largest dose-reponses were observed for endo-brevicomin, E,Z-chalcogran, ipsenol, pino-/isopinocamphone (1:2), and E-7-methyl-1,6-dioxaspiro(4,5) decane (MAD). These compounds, along with the known attractants frontalin and alpha-pinene, were tested in the primary EAG study using a larger sample size. The individual compounds did not elicit responses greater than the standard mixture of oxygenated monoterpenes. Overall, no significant differences were observed in EAGs between males and females. However, females exhibited a lower threshold of response than males to alpha-pinene and ipsenol, whereas males exhibited a lower threshold of response than females to MAD and pino-/isopinocamphone (1:2). At 1 µg/µl, E,Z-chalcogran and MAD elicited significantly greater EAGs relative to the standard, than the other test compounds. Differences among the compounds were less pronounced at 10 µg/µl. Most of the test compounds elicited similar responses and it is suggested that several of the compounds may be used together by C. pissodis in habitat and/or host community location.
DE: Semiochemicals\Insect pests\Scolytidae\Coleoptera\Forest pests\Braconidae\Hymenoptera\Beneficial insects\Natural enemies\Physiology\Dendroctonus frontalis\parasitoids\Coeloides pissodis\hosts\biology\behaviour\behaviour\attractants\parasites
AN: 0E08202121\0F05503664\7E01501457
TI: Turbulence, trees and semiochemicals: wind-tunnel orientation of the predator, Rhizophagus grandis, to its barkbeetle prey, Dendroctonus micans..
AU: Wyatt, T. D.\ Phillips, A. D. G.\ Gregoire, J. C.
JN: Physiological Entomology
YR: 1993
VL: 18
NO: 2
PP: 204-210
LA: En
MS: 23 ref.
AA: Cleppa Park Field Research Station, University of Wales, UK.
AB: Insects apparently responding to the visual stimulus offered by a tree or any other object may also be responding to the variety of physical effects caused by the obstruction, including turbulence, a reduction in wind velocity and eddies. The relative importance of prey odour associated with the bark beetle Dendroctonus micans, a prey-host-tree odour, a silhouette, and physical barrier to the wind in the orientation and landing behaviour of a predator, Rhizophagus grandis, were investigated. R. grandis responded very strongly to the frass of its prey when presented on a 'tree' but not to the same quantity of frass presented alone. Frass on black plastic uPVC pipes was significantly more attractive than frass on real host tree logs, suggesting that host-tree volatiles do not enhance the attractiveness of prey frass. R. grandis responded to 'transparent' Mylar 3-dimensional cylinders in the same way as they did to the black plastic pipes. R. grandis was also tested with frass and 2-dimensional stimuli offering a visual stimulus or physical barrier alone, or in combination. Frass with a 2-dimensional visual stimulus was no better than frass alone: few insects landed. Significantly more insects were attracted to the same 2-dimensional visual stimulus with a hidden upwind barrier producing turbulence, but a similar number were attracted to the frass in front of the hidden barrier alone. As many plants were similar in size to the logs used in these experiments, it is concluded that comparable effects might influence the behaviour of other phytophagous insects, their predators and parasitoids.
DE: Insect pests\Scolytidae\Coleoptera\Rhizophagidae\Coleoptera\Natural enemies\Beneficial insects\Predatory insects\Bark beetles\Forest pests\smell\Flight\Parasitoids\Vision\Senses\Rhizophagus grandis\biology\behaviour\Dendroctonus micans\predators\prey\Semiochemicals\attractants\Kairomones\kairomon es
AN: 0E08111604\0F05502245\7E01500322
TI: Adult experience modifies attraction of the leafminer parasitoid Opius dissitus (Hymenoptera: Braconidae) to volatile semiochemicals.
AU: Petitt, F. L.\ Turlings, T. C. J.\ Wolf, S. P.
JN: Journal of Insect Behavior
YR: 1992
VL: 5
NO: 5
PP: 623-634
LA: En
MS: 35 ref.
AA: The Land, EPCOT Center, P.O. Box 10<thin>000 Lake Buena Vista, FL 32830, USA.
AB: Oviposition-experienced females of Opius dissitus, a braconid parasitoid of Liriomyza sativae, preferentially landed on infested rather than uninfested lima bean (Phaseolus lunatus) plants in a flight tunnel assay. Both native and oviposition-experienced parasitoids responded strongly to odours of infested P. lunatus plants in a 4-arm olfactometer in comparison with odours of uninfested plants, suggesting that volatile semiochemicals were used in host location. Parasitoids with an oviposition experience on P. lunatus ('lima-experienced') spent significantly more time in the infested odour than naive individuals. However, aubergine-experienced braconids did not spend significantly more time in the infested odour field than naive braconids. When parasitoids reared on L. sativae in P. lunatus were given a choice between the odour of infested P. lunatus and the odour of infested aubergines or cotton, naive and P. lunatus-experienced braconids preferred infested P. lunatus odour. An oviposition experience on the other plant species resulted in a dramatic shift in preference. It was concluded that the experience effect was due, at least in part, to associative learning, as has been reported for other parasitoids. The parasitoids may perceive unconditioned stimuli during host contact and oviposition on an infested leaf, and may associate those stimuli with volatile semiochemicals emanating from the leaf or host. Subsequently, the volatiles associated with the presence of hosts are used in directing the search for hosts.
DE: Insect pests\ Diptera\ Agromyzidae\ Hymenoptera\ Braconidae\ Natural enemies\ Beneficial insects\ Grain legumes\ Fibre plants\ Fruit vegetables\ Oviposition\Liriomyza sativae\ parasitoids\Opius dissitus\hosts\biology\behaviour\ Aubergines\Cotton\Phaseolus lunatus\food plants\ Semiochemicals\attractants\parasitoids\semiochemicals\attractants AN: 0E08110865\7E01501430
TI: Reactions of adult female parasitoids, particularly Aphidius rhopalosiphi, to volatile chemical cues from the host plants of their aphid prey.
AU: Wickremasinghe, M. G. V.\ Emden, H. F. van
JN: Physiological Entomology
YR: 1992
VL: 17
NO: 3
PP: 297-304
LA: En
MS: 12 ref.
AA: Department of Horticulture, University of Reading, Reading, UK.
AB: In Y-tube olfactometer tests, Aphidius ervi, Prao sp., Aphelinus flavus, Lysiphlebus fabarum and Aphidius rhopalosiphi responded positively to the odour of the plant on which host aphid mummies containing them had been collected. The response to host plant odour was greater than the response to the odour of host aphids, their honeydew or a combination of the two. The strongest response was to a combination of plant and host aphids. A. rhopalosiphi showed a strong positive response to 3 wheat volatiles (cis-3-hexenyl acetate, cis-3-hexen-1-ol and trans-2-hexenal) as well as to indole-3-acetaldehyde (a breakdown product of tryptophan in honeydew of its host, Rhopalosiphum padi). In both olfactometer tests with odours and choice trials with whole plants, newly emerged A. rhopalosiphi distinguished and preferred the variety of wheat on which their development had occurred compared to other wheat varieties.
DE: Insect pests\ Aphididae\ Hemiptera\ Natural enemies\ Beneficial insects\ Cereals\ Honeydew\ Tryptophan\ Volatile compounds\ Braconidae\ Hymenoptera\ Aphelinidae\Aphidius ervi\biology\ behaviour\Praon\Aphelinus flavus\Lysiphlebus fabarum\Aphidius rhopalosiphi\(Z)-3-Hexenyl acetate\effects\(Z)-3-Hexen-1-ol\ (E)-2-Hexenal\Indole-3-acetaldehyde\Semiochemicals\Aphidius rhopalosiphi\plant extracts\Wheat\extracts\Rhopalosiphum padi\parasitoids\hosts\ Aphidius ervi\biology\behaviour\Praon\Aphelinus flavus\ Lysiphlebus fabarum\Aphidius rhopalosiphi\Semiochemicals\ effects\Aphidius rhopalosiphi\plant extracts\Wheat\extracts\ Rhopalosiphum padi\parasitoids\hosts\ Triticum\Aphididae\plant extracts
AN: 0E08104790\7E01401746\6T01004438
TI: Effect of host diet and preflight experience on the flight responses of Microplitis croceipes (Cresson).
AU: Eller, F. J.\ Tumlinson, J. H.\ Lewis, W. J.
JN: Physiological Entomology
YR: 1992
VL: 17
NO: 3
PP: 235-240
LA: En
MS: 37 ref.
AA: USDA, ARS, Insect Attractants Laboratory, Gainesville, FL, USA.
AB: Females of Microplitis croceipes [Glabromicroplitis croceipes] without previous exposure to host diet, feeding damage or faeces, and with no oviposition experience (i.e. inexperienced) exhibited flight tunnel responses towards extracts of faeces from several diet-host species combinations, excluding artificial diet. Inexperienced females exhibited the following order of preference to faeces from larvae of its host, Heliothis zea [Helicoverpa zea] fed selected diets: cotton wild geranium > cowpea > artificial diet, suggesting an adaptation to 'preferred' host plants. Females having a preflight experience with a plant-host complex (PHC) prior to testing exhibited a higher percentage of oriented flights in the wind tunnel than did inexperienced females. Oviposition per se had little effect on the flight response of females. The increased flight response after an experience was apparently due to a combination of sensitization and associative learning. In a choice situation, a single experience was insufficient to establish a preference for the PHC-experienced insects; however, repeated experience resulted in preferences, and the degree of preference tended to increase with the number of experiences.
DE: Insect pests\ Noctuidae\ Lepidoptera\ Hymenoptera\ Braconidae\ Natural enemies\ Beneficial insects\ Flight\ Synthetic diets\ Oviposition\ Reproduction\ Fibre plants\ Grain legumes\ Feeding\Glabromicroplitis croceipes\biology\ behaviour\Helicoverpa zea\parasitoids\hosts\Semiochemicals\ effects\Cotton\Cowpeas\Pelargonium\crops\diets\ Glabromicroplitis croceipes\biology\behaviour\Helicoverpa zea\ parasitoids\Glabromicroplitis croceipes\hosts\Semiochemicals\ effects
AN: 0E08104504\7E01401745
TI: The semiochemical complexes that mediate insect parasitoid foraging.
AU: Tumlinson, J. H.\ Turlings, T. C. J.\ Lewis, W. J.
JN: Agricultural Zoology Reviews
YR: 1992
VL: 5
PP: 221-252
LA: En
MS: 7 ref.
AA: Insect Attractants, Behavior and Basic Biology Research Laboratory, ARS, USDA, Gainesville, FL 32604, USA.
AB: In this review of the semiochemical-mediated interactions of parasitoids and their hosts, the functions of the long- and short-range kairomones produced by the host insects, of long-range attractants from plants or substrates and of parasitoid-produced semiochemicals are discussed. All of the long-range kairomones so far identified have been the sex pheromones of the hosts. Examples of where the application of sex pheromones increased parasitization are given. Short-range host-produced chemicals are shown to often act as arrestants and/or stimulate more intense searching behaviour. The attraction of parasitoids to the undamaged and damaged food plants of their hosts is illustrated. It is concluded that the learning behaviour of the parasitoids provides them with a flexibility necessary to select the potentially most profitable cues from among the many in a complex matrix. Thus, while foraging is regulated to a great extent by the physiological condition and genetic potential of the parasitoids, their ability to learn provides the plasticity essential for survival.
DE: Natural enemies\ Beneficial insects\ Attractants\ Sex pheromones\ Insect pests\ Learning\ Foraging\ Reproduction\ Parasitoids\biology\behaviour\Reviews\semiochemicals\ interactions\ Parasitoids\biology\behaviour\Reviews\semiochemicals\ interactions
AN: 0E08102161\7E01401147
TI: Ecology of infochemical use by natural enemies in a tritrophic context.
AU: Vet, L. E. M.\ Dicke, M.
JN: Annual Review of Entomology
YR: 1992
NO: No. 37
PP: 141-172
LA: En
MS: 200 ref.
AA: Department of Entomology, Wageningen Agricultural University, PO Box 8031, 6700 Wageningen, Netherlands.
AB: The use of chemical information from the first and second trophic levels of plant-herbivore-parasitoid/predator systems by natural enemies is reviewed from an evolutionary and ecological standpoint. The basic concept of the review is that information from the first and second trophic levels differs in availability and reliability and that this difference shapes the way in which infochemicals are used by a species. The use of stimuli from the second and first trophic level is discussed in the context of reliability versus detectability. It is suggested that natural enemies that attack feeding stages of herbivores can be expected to use well-detectable and reliable herbivore-induced synomones. When the release of these chemicals is limited, information from other stages may be used or easy-to-detect stimuli may be learnt. Nongenetic variation in response to infochemicals resulting from learning processes or variation in the physiological state and its affect on the reliability- detectability problem is discussed in the next section. Herbivore-produced kairomones generally evoke strong and congenitally fixed responses, while responses to plant volatiles are more plastic. Reliable host-derived stimuli serve as reinforcers in associative learning through which parasitoids acquire or enhance responses to less reliable but more detectable plant volatiles. Genetic and nongenetic variation in infochemical production by herbivores is outlined. The dietary specialization of natural enemies is correlated with the way in which they employ infochemicals to generate some testable general hypotheses. The status of, and prospects for, the application of infochemicals in pest management are evaluated.
DE: parasitoids\ predators\ natural enemies\ beneficial insects\ reviews\insects\semiochemicals
AN: 0E08003246