Lutte biologique contre la cochenille du manioc (Phenacoccus manihoti) avec le parasitoïde exotique, Epidinocarsis lopezi

Dans IDL-1152

Impact of the exotic parasitoid Epidinocarsis lopezi on cassava mealybug (Phenacoccus manihoti) populations

Published online: 01 Dec 1987Epidinocarsis lopezi an exotic parasitoid to Africa, was first released to control the cassava mealybug (CM), Phenacoccus manihoti, at IITA (Ibadan) in November 1981, and a year later at Abeokuta, both in southwestern Nigeria. Population dynamics study of CM and its natural enemies was conducted for 4 years. CM population peaks usually occurred during the second half of the dry season (January-April). E. lopezi was the only natural enemy that was found during the whole year and in high densities. Parasitization rates of E. lopezi alternated with CM densities, thus suggesting a regulatory effect on CM populations by this parasitoid. CM populations were drastically reduced in release fields when compared with control fields. Subsequently CM populations have been maintained below injury levels for 4 years. E. lopezi is considered an efficient parasitoid of the CM

Food web of insects associated with the cassava mealybug, Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae), and its introduced parasitoid, Epidinocarsis lopezi (De Santis) (Hymenoptera: Encyrtidae), in Africa

Published online: 01 July 2009About 130 species of parasitoids and predators are reported, most of them for the first time, to be associated directly or indirectly with the cassava pest Phenacoccus manihoti Matile-Ferrero and its parasitoid, Epidinocarsis lopezi (De Santis), newly introduced into Africa as a biological control agent. About 20 species are common. The species are grouped in 11 guilds, which include the indigenous hyperparasitoids, which originally attacked parasitoids of other mealybugs, the predators with which E. lopezi competes for the same food source and their antagonists

Introduction and dispersal of Epidinocarsis lopezi (Hym., Encyrtidae), an exotic parasitoid of the cassava mealybug, Phenacoccus manihoti (Hom., Pseudococcidae), in Africa

Published online: 27 Jun 2003In 1981 the South American parasitoid Epidinocarsis lopezi (DeSantis) was imported into Nigeria for control of the cassava mealybug, Phenacoccus manihoti Mat.-Ferr. It was multiplied in an insectary at the International Institute of Tropical Agriculture (IITA), Ibadan, and first released in 1981/82. Within 3 years it dispersed over 200 000 km2 in southwestern Nigeria, occupying between 70 and 98% of all fields. By December 1985, a total of over 50 releases in 34 regions had been made in 12 African countries. E. lopezi was already established in 28 regions, and in some cases E. lopezi spread across international borders. It now occupies 650 000 km2 in 13 countries: 420 000 km2 in West Africa, 210 000 km2 in Central Africa and several small disjunct territories, covering a range of ecological zones (Sudan Savannah, Guinea Savannah, Equatorial Rainforest, Highlands)

Economics of biological control of cassava mealybug in Africa

Pest populations of the cassava mealybug Phenacoccus manihoti Mat.-Ferr. (Homoptera: Pseudococcidae) were reduced successfully by the biological control agent Apoanagyrus (Epidinocarsis) lopezi De Santis (Hymenoptera: Encyrtidae) throughout most of sub-Saharan Africa. The economics of the project were evaluated based on data from field trials, socio-economic surveys, published results, and financial information provided by the International Institute of Tropical Agriculture (IITA) and the national programmes. Costs and benefits for the biological control of P. manihoti were calculated over 40 years (1974-2013) for 27 African countries, for four different scenarios, taking into account that impact by A. lopezi and speed of the impact differ between ecological zones. A reasonable calculation considering compounded interest resulted in a benefit cost ratio of about 200 when cassava was costed at world market prices, and of about 370-740 when inter-African prices were considered.© 2001 Elsevier Science B.V. All rights reserved

Economics of biological control of cassava mealybug in Africa

Pest populations of the cassava mealybug Phenacoccus manihoti Mat.-Ferr. (Homoptera: Pseudococcidae) were reduced successfully by the biological control agent Apoanagyrus (Epidinocarsis) lopezi De Santis (Hymenoptera: Encyrtidae) throughout most of sub-Saharan Africa. The economics of the project were evaluated based on data from field trials, socio-economic surveys, published results, and financial information provided by the International Institute of Tropical Agriculture (IITA) and the national programmes. Costs and benefits for the biological control of P. manihoti were calculated over 40 years (1974-2013) for 27 African countries, for four different scenarios, taking into account that impact by A. lopezi and speed of the impact differ between ecological zones. A reasonable calculation considering compounded interest resulted in a benefit cost ratio of about 200 when cassava was costed at world market prices, and of about 370-740 when inter-African prices were considered.© 2001 Elsevier Science B.V. All rights reserved

Biological control of the cassava mealybug, Phenacoccus manihoti, by the exotic parasitoid Epidinocarsis lopezi in Africa [and Discussion]

Since its accidental introduction into Africa, the cassava mealybug (CM) has spread to about 25 countries. The specific parasitoid Epidinocarsis lopezi, introduced from South America, its area of origin, into Nigeria in 1981, has since been released in more than 50 sites. By the end of 1986 it was established in 16 countries and more than 750 000 km$^2$. In southwestern Nigeria, CM populations declined after two initial releases, and have since remained low. During the same period, populations of indigenous predators of CM, mainly coccinellids, have declined, as have indigenous hyper-parasitoids on E. lopezi, because of scarcer hosts. Results from laboratory bionomic studies were incorporated into a simulation model. The model, field studies on population dynamics, and experiments excluding E. lopezi by physical or chemical means demonstrate its efficiency, despite its low reproductive potential