Control biologico del gusano cachon (Erinnyis ello)

A program of biological control of the cassava hornworm appears feasible. The following biological control agents have been found to reduce hornworm populations effectively: Trichogramma spp. (egg parasites), Apanteles spp. (larval parasites), Polistes spp. (larval predators) and Bacillus thuringiensis (pathogenic to larvae). Further studies are required to develop the program better and test it at a commercial level. (AS-CIAT

El piojo harinoso (Phenacoccus sp.) de la yuca; una de las plagas agricolas mas importantes en el mundo

Cassava mealybugs constitute one of the major production problems of cassava in Africa and the Americas. The species already identified that attack cassava in the Americas include Phenacoccus manihoti, P. herreni, P. gossypii, and P. grenadensis. Since its introduction into Africa, P. manihoti has caused considerable yield losses in some regions, especially Zaire. In the Americas, severe outbreaks of P. herreni have been reported in several areas of Brazil, Colombia, and the Guianas. These 2 species are similar taxonomically and in plant damage symptoms but differ biologically. The initial and most severe attack of both species occurs on the growing point of the cassava plant shoots. Plant reaction consists of a rosetting effect on the apical leaves which results in a cabbage-like appearance of the shoot. High mealybug populations, together with the stress caused by drought, cause defoliation, deformation of the shoots, shortening of internodes, and distortion of stems. The bionomics of both species differ in that P. herreni is bisexual and P. manihoti reproduces parthenogenetically. Biological studies on P. herreni show that the female passesthrough 3 instars before the adult stage. The complete life cycle from egg to adult lasts 49.5 days. Males pass through 4 instars before the adult stage, in which the adult male is winged. The whole cycle lasts 29.5 days. The cassava mealybug has numerous natural enemies. Biological control combined with resistance offers a healthy and economical control of the pest. Tables are included on the life cycle of P. herreni and P. gossypii on plants of cassava var. M Col 113 under lab. conditions, size and size increase of P. herreni on cassava under greenhouse conditions, hyperparasites of Phenacoccus spp. in Latin America, populations of natural enemies of the cassava mealybug in the field, and natural enemies of P. gossypii and P. herreni in Latin America and the Caribbean. (AS

Manejo de plagas en yuca

Aspects related to pest management in cassava are discussed: (1) favorable factors involved insect/plant/environment interactions; (2) characteristics of insect survival; (3) integrated, biological control and pest management. On the basis of research conducted by CIAT on Erinnyis ello, a management program is proposed which incorporates different techniques such as biological control [natural enemies of eggs (Trichogramma spp., Telenomus spp.), larvae (Polistes spp., Podisus sp., Apanteles sp., Drino sp., Belsovia sp. and Chetogena sp.) and pathogens (Bacillus spp. and the nuclear granulosis virus)], light traps and manual collection of larvae. The habits, order and family of parasites, predators and pathogens of E. ello are given in table form. (CIAT)Se discuten aspectos relacionados con el manejo de plagas en la yuca: 1) factores favorables involucrados en la interaccion insecto/planta/medio ambiente; 2) caracteristicas de supervivencia de los insectos; 3) control integrado, biologico y manejo de plagas. Con base en las investigaciones realizadas por el CIAT sobre Erinnyis ello, se propone un programa de manejo que incorpora diferentes tecnicas como: control biologico (enemigos naturales de huevos (Trichogramma spp., Telenomus sp.), de larvas (Polistes spp., Podisus sp., Apanteles sp., Drino sp., Belsovia sp., y Chetogena sp.) y patogenos (Bacillus spp. y el virus de la granulosis nuclear), trampas de luz y recoleccion manual de larvas. Se presentan en forma de cuadro los habitos, ordenes y familias de los parasitos, predatores y patogenos de E. ello. (CIAT