Annales de la Société Entomologique de France (2007) 43, 139-144
Auguste Ndoutoume-Ndong and Danielle Rojas-Rousse (2007)
Y a-t-il élimination d´Eupelmus orientalis Crawford par Eupelmus vuilleti Crawford (Hymenoptera : Eupelmidae) des systèmes de stockage du niébé (Vigna unguiculata Walp) ?
[Is there elimination of Eupelmus orientalis Crawford by Eupelmus vuilleti Crawford (Hymenoptera: Eupelmidae) out of the niebe (Vigna unguiculata Walp) stocks?]
Annales de la Société Entomologique de France 43 (2), 139-144
Abstract: Cowpea is a food leguminous plant cultivated in tropical Africa for its seeds rich in proteins. The main problem for its production is the conservation of the harvests. In the fields as in the stocks, the seeds are destroyed by pests (bruchids). These bruchids are always associated with several entomophagous species of Hymenoptera. Four entomophagous species were listed: an egg parasitoid (Uscana lariophaga Stephan), and three solitary larval and pupal ectoparasitoids (Dinarmus basalis Rondoni, Pteromalidae; Eupelmus vuilleti Crawford and E. orientalis Crawford, Eupelmidae). The survey of the populations shows that at the beginning of storage, E. orientalis is the most abundant specie (72 %) whereas E. vuilleti and D. basalis respectively represent 12 % and 16 % of the Hymenoptera. During storage, the E. orientalis population decreases gradually and it disappears completely in less than two months after the beginning of storage. E. vuilleti population becomes gradually more important than D. basalis population which regress until less than 10 % of the emerging parasitoids. E vuilleti adopts ovicidal and larvicidal behaviour against D. basalis. This behaviour explains its population regression inside granaries. If the aggressive behaviour of this Eupelmidae is a constant, that could also explain the disappearance of E. orientalis. However if this species is maintained in stocks, it would be an effective control agent of bruchids according to their parasitic capacities. This study shows that the ovicidal and larvicidal behaviour of E. vuilleti is not expressed against E. orientalis. When all the available potential hosts are already parasitized by E. orientalis, the females of E. vuilleti do not lay eggs. The disappearance of E. orientalis could not thus be explained by the presence of E. vuilleti.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
(original language: French)
Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
population dynamics/epizootiology
environment/habitat manipulation
Pest and/or beneficial records:
| Beneficial | Pest/Disease/Weed | Crop/Product | Country | Quarant.
|
|---|---|---|---|---|
| Uscana lariophaga (parasitoid) | ||||
| Dinarmus basalis (parasitoid) | ||||
| Eupelmus vuilleti (parasitoid) | ||||
| Eupelmus orientalis (parasitoid) |
