CABI - Biocontrol News and Information 19(3) September 1998 News

In this section we welcome all your experiences in working directly with the end-users of arthropod and microbial biocontrol agents or in educational activities on natural enemies aimed at students, farmers, extension staff or policymakers.

In order to become less dependent on expensive chemical inputs, maize farmers in the smallholder settlement El Palmar in the district of Pena, Yaracuy State, decided to get involved in production and promotion of biological control agents for control of the fall armyworm, Spodoptera frugiperda, one of the key caterpillar pests in maize. With technical support from the National Fund for Agricultural Research (FONAIAP), Mr Jesus Lima and Mr Luis Bello from the farmers' cooperative MECOIVEPAL set up a cottage-industry unit to mass rear the parasitic wasp Telenomus remus. Telenomus remus parasitizes the eggs of armyworms, with one wasp larva developing inside each host egg. The rearing and distribution is run as a farm family concern, involving women, teenagers and children.

To begin with, 200 recently hatched S. frugiperda are reared on leaves of the castor oil plant Ricinus communis, which eliminates the cannibalistic tendencies of the larvae and allows five or more to be reared together in each five-litre plastic jar. The leaves are kept turgid by inserting the leafstalks through a small hole in the jar and into a container of water. After five days the larvae are transferred to a wooden box partly filled with sand and fed with fresh castor oil leaves until pupation after 15-17 days. Pupae are collected by sieving the sand and these are placed in five-litre plastic jars for adult emergence. Once they have emerged, the moths are transferred using an aspirator into one-litre metal jars containing paper folded concertina-fashion for egglaying. Eggs for parasitization are placed in five-litre glass jars at an approximate ratio of 20 host eggs per wasp. After 24 hours parasitization exposure, any host larvae hatching from unparasitized eggs are removed daily for seven days. The remaining (presumed parasitized) host eggs are placed in 750-cc plastic containers with honey provided for the adult parasitoids, which begin to emerge on day ten. Each pot contains 1000-1500 wasps, and pots are distributed for field release at a rate of 4000-6000 individuals per hectare of planted maize.

Moth emergence units and larval rearing methods have been adapted from those developed by the commercial beneficials company ServBio C. A. (near Barquisimento) to enable production at ambient temperature and relative humidity. Up to 50,000 host eggs can be produced each day for parasitization or restocking host cultures. The newly emerged adult wasps are only suitable for field release for three days although they may be stored in a domestic refrigerator at 8-14°C for up to seven days.

The unit at El Palmar produced 350,000 wasps over a ten week period in 1997, at a cost of US$260. Each wasp is valued commercially at US$0.0022 (0.22 cents!), thus the economic value was US$794 and profitability was 67.3%. Production was sufficient to control fall armyworm by IPM methods over 87.5 ha at a cost of US$10.58/ha for wasp inputs. Current chemical control in the area costs US$17.58/ha per insecticide application, thus the programme enabled participating farmers to save a total of US$3266. It is crucial to plan and co-ordinate wasp production with the area and timing of maize sowing in the locality. Host production needs to be started one month before crop sowing to guarantee an adequate supply of wasps for field release in the first four weeks after germination.

In addition to meeting demand from farmers in the cooperative, the unit helped create employment and serves as a support centre for other organizations interested in non-chemical pest management.

The family members involved have trained other local residents, including students, housewives and farmers in both the technical aspects of the rearing methodology and the ecological and economic benefits of biological control. There are over 30 smallholder associations growing maize in Yaracuy State who could adopt the rearing system in the medium or long term. The El Palmar farmers have been sharing their experience and conviction of the benefits of biological control with other farmers and students in Venezuela and beyond. At a recent seminar on biological control in Peru, Mr Lima described how he had virtually eliminated insecticide use in his maize crop, thanks to the work of natural enemies, or as he prefers to call them, his "natural friends".

Contact: Blas Linares, FONAIAP, CIAEY, Km3 via Aeropuerto, Sector La Ermita, Apdo. 110, San Felipe, Edo. Yaracuy, Venezuela.
Email:
Fax: + 58 54 312265

Outstanding training methods and materials were identified as an important component in the success of IPM implementation and training programmes for Andean potatoes.

The MIPANDES (Integrated Pest Management for Andean Communities) Project began in 1993, executed by CARE-Peru, with technical support from CIP (Centro Internacional de la Papa/International Potato Center) and funding from USAID. Some 3500 smallholder families in four departments in Peru learned about key pest relationships and the benefits of adopting IPM practices. They were taught about the life cycles of the principal pests, Andean potato weevil (Premnotrypes vorax) and potato tuber moth (Phthorimaea operculella), their relationships with the potato plant, and how, when and where to find each developmental stage. Many had previously been unaware that the adult weevils they saw in their plots were related to the larvae found in the tubers.

The farmers were provided with a menu of IPM practices that could be used to reduce populations of the Andean potato weevil and potato tuber moth - together with education on safety aspects of pesticide use. The adoption of IPM procedures has been almost universal in community fields, and although adoption is somewhat less in individual plots, there is evidence that some measures are being spontaneously adopted in non-MIPANDES communities. The most commonly adopted practices include night collection of adult weevils, earthing up, harvesting tubers on canvas or plastic sheets, planting live fences, and the use of repellent plants and baculoviruses on stored potatoes.

In general, the farmer view was that IPM works. Almost 80% of 479 family units interviewed said that the IPM practices had reduce insect pest damage; some 30% recorded annual savings of US$40 or more associated with decreased pesticide costs (annual income amongst these farmers averages some US$470). IPM practices that have been tried and shown to be cost-effective by farmers have the best chance of being adopted permanently.

In the Bolivian altiplano, several NGOs are working with CIP in training and implementation of IPM for potato pests and diseases. The NGO PROSUKO is studying the use of the fungus Beauveria brongniartii for control of potato weevil (Premnotrypes spp.). In 115 farm families involved in the CIP Weevil-IPM programme the following IPM practices have been adopted: plastic covered field border trenches to trap adults (100%); removal of sources of infestation (90%); use of chickens as predators (80%); targeted insecticide application (70%); elimination of volunteer plants (60%); and manual collection of adults and larvae (50%). Competitions are organized for weevil collecting `marathons'.

The Guatemalan potato moth Tecia solanivora is a major pest in Boyaca Department, Colombia where CIP and its partner institutions are promoting the use of sex pheromones, manual collection and a baculovirus for its control. Potato farmers purchased 11,943 pheromone plugs and 981 kg of baculovirus in the second semester of 1997. Training activities include a puppet show about the moth as a novel method of raising awareness of IPM methods among Andean farming communities.

Contact: Fausto Cisneros, Centro Internacional de la Papa, Apartado 1558,
Lima 100, Peru.
Email:
Fax: + 51 1 436 6920