Melanization of eggs and larvae of the parasitoid, Epidinocarsis lopezi (Hymenoptera: Encyrtidae), by the cassava mealybug, Phenacoccus manihoti (Homoptera:Pseudococcidae)

The encyrtid wasp Epidinocarsis lopezi (De Santis) has been introduced into Africa as a biological control agent against the cassava mealybug Phenacoccus manihoti Matile-Ferrero. This host has a defense reaction against the immature parasitoid that involves encapsulation and melanization. Under labo...

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Autores principales: Sullivan, D.J., Neuenschwander, Peter
Formato: Journal Article
Lenguaje:Inglés
Publicado: Cambridge University Press 1988
Materias:
Acceso en línea:https://hdl.handle.net/10568/108745
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author Sullivan, D.J.
Neuenschwander, Peter
author_browse Neuenschwander, Peter
Sullivan, D.J.
author_facet Sullivan, D.J.
Neuenschwander, Peter
author_sort Sullivan, D.J.
collection Repository of Agricultural Research Outputs (CGSpace)
description The encyrtid wasp Epidinocarsis lopezi (De Santis) has been introduced into Africa as a biological control agent against the cassava mealybug Phenacoccus manihoti Matile-Ferrero. This host has a defense reaction against the immature parasitoid that involves encapsulation and melanization. Under laboratory conditions, 37.5% of once-stung cassava mealybugs had been parasitized, as indicated by eggs and larvae of the parasitoid in dissected hosts. Of these parasitized cassava mealybugs, 89.6% contained melanized particles (egg, partially melanized larva, internal host tissues, exoskeleton wound scars). Some of the parasitoid larvae were only partially melanized, and either freed themselves from the melanized capsule or else shed it at the next molt. By the 3rd day of their development only 12.5% were completely melanized. In cassava mealybugs with melanized host tissue but no living parasitoid, the survival of the host was not affected by the melanization. The mealybug itself sometimes shed black particles at the next molt and these were found attached to the cast skins. When superparasitized in the laboratory, 68.6% of twice-stung cassava mealybugs contained parasitoids. Mummies collected from a field experiment showed that melanization rates of mummies increased with increasing parasitization rates. Thus, melanization in the cassava mealybug was commonly triggered when E. lopezi oviposited, but this defense reaction was mostly ineffective, permitting the introduced parasitoid to be a successful biological control agent in Africa against the cassava mealybug, a major pest on this important food crop.
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spelling CGSpace1087452024-05-01T08:15:54Z Melanization of eggs and larvae of the parasitoid, Epidinocarsis lopezi (Hymenoptera: Encyrtidae), by the cassava mealybug, Phenacoccus manihoti (Homoptera:Pseudococcidae) Sullivan, D.J. Neuenschwander, Peter cassava parasitoids phenacoccus manihoti epidinocarsis lopezi biological control molecular biology physiology The encyrtid wasp Epidinocarsis lopezi (De Santis) has been introduced into Africa as a biological control agent against the cassava mealybug Phenacoccus manihoti Matile-Ferrero. This host has a defense reaction against the immature parasitoid that involves encapsulation and melanization. Under laboratory conditions, 37.5% of once-stung cassava mealybugs had been parasitized, as indicated by eggs and larvae of the parasitoid in dissected hosts. Of these parasitized cassava mealybugs, 89.6% contained melanized particles (egg, partially melanized larva, internal host tissues, exoskeleton wound scars). Some of the parasitoid larvae were only partially melanized, and either freed themselves from the melanized capsule or else shed it at the next molt. By the 3rd day of their development only 12.5% were completely melanized. In cassava mealybugs with melanized host tissue but no living parasitoid, the survival of the host was not affected by the melanization. The mealybug itself sometimes shed black particles at the next molt and these were found attached to the cast skins. When superparasitized in the laboratory, 68.6% of twice-stung cassava mealybugs contained parasitoids. Mummies collected from a field experiment showed that melanization rates of mummies increased with increasing parasitization rates. Thus, melanization in the cassava mealybug was commonly triggered when E. lopezi oviposited, but this defense reaction was mostly ineffective, permitting the introduced parasitoid to be a successful biological control agent in Africa against the cassava mealybug, a major pest on this important food crop. 1988-01 2020-07-13T14:39:14Z 2020-07-13T14:39:14Z Journal Article https://hdl.handle.net/10568/108745 en Limited Access Cambridge University Press Sullivan, D.J. & Neuenschwander, P. (1988). Melanization of eggs and larvae of the parasitoid, Epidinocarsis lopezi (De Santis)(Hymenoptera: Encyrtidae), by the cassava mealybug, Phenacoccus manihoti Matile-Ferrero (Homoptera: Pseudococcidae). The Canadian Entomologist, 120(1), 63-71.
spellingShingle cassava
parasitoids
phenacoccus manihoti
epidinocarsis lopezi
biological control
molecular biology
physiology
Sullivan, D.J.
Neuenschwander, Peter
Melanization of eggs and larvae of the parasitoid, Epidinocarsis lopezi (Hymenoptera: Encyrtidae), by the cassava mealybug, Phenacoccus manihoti (Homoptera:Pseudococcidae)
title Melanization of eggs and larvae of the parasitoid, Epidinocarsis lopezi (Hymenoptera: Encyrtidae), by the cassava mealybug, Phenacoccus manihoti (Homoptera:Pseudococcidae)
title_full Melanization of eggs and larvae of the parasitoid, Epidinocarsis lopezi (Hymenoptera: Encyrtidae), by the cassava mealybug, Phenacoccus manihoti (Homoptera:Pseudococcidae)
title_fullStr Melanization of eggs and larvae of the parasitoid, Epidinocarsis lopezi (Hymenoptera: Encyrtidae), by the cassava mealybug, Phenacoccus manihoti (Homoptera:Pseudococcidae)
title_full_unstemmed Melanization of eggs and larvae of the parasitoid, Epidinocarsis lopezi (Hymenoptera: Encyrtidae), by the cassava mealybug, Phenacoccus manihoti (Homoptera:Pseudococcidae)
title_short Melanization of eggs and larvae of the parasitoid, Epidinocarsis lopezi (Hymenoptera: Encyrtidae), by the cassava mealybug, Phenacoccus manihoti (Homoptera:Pseudococcidae)
title_sort melanization of eggs and larvae of the parasitoid epidinocarsis lopezi hymenoptera encyrtidae by the cassava mealybug phenacoccus manihoti homoptera pseudococcidae
topic cassava
parasitoids
phenacoccus manihoti
epidinocarsis lopezi
biological control
molecular biology
physiology
url https://hdl.handle.net/10568/108745
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