Monday, 18 November 2002 - 2:48 PM
0447

This presentation is part of : Student Competition Ten-Minute Papers, Subsection Ca2. Biological Control

Host suitability of various stored product insects for two strains of the parasitoid Anisopteromalus calandrae (Hymenoptera: Pteromalidae)

Mukti N Ghimire and Thomas W. Phillips. Oklahoma State University, Entomology and Plant Pathology, 127 Noble Research Center, Oklahoma State University, Stillwater, OK

Anisopteromalus calandrae (Howard) is a synovegenic solitary ectoparasitic wasp that attacks concealed larvae of stored product pests. Host suitability is a key factor to optimize biological control programs. We investigated host suitability for the development of two strains of A. calandrae, a laboratory strain reared on rice weevil and a field strain collected with the lesser grain borer using four different hosts: the cigarette beetle (CB) Lasioderma serricorne (F.), rice weevil (RW) Sitophilus oryzae (L.), lesser grain borer (LGB) Rhyzopertha dominica (F.), and Angoumois grain moth (AGM) Sitotroga cerealella (Oliv.). The study was conducted in a no-choice design in Petri dishes as arenas with 20 last instar larvae of each host species. Mated and conditioned female A. calandrae were introduced singly into arenas and allowed to sting and oviposit for 24 hours.

Parasitism by the LGB strain was greater than that for the RW strain across all hosts. No parasitism was found on AGM for either strain in this experiment. The highest parasitism was recorded on CB (79.88%) followed by RW (69.61%) and LGB (64.83%) by the LGB strain. In contrast, parasitism was highest on RW (72.39%) followed by CB (57.38%) and LGB (37.14%) by the RW strain. A female-biased sex ratio was observed for both strains of the wasp across the hosts except for a male-biased sex ratio produced on the LGB by the RW strain. This study indicates that conspecific parasitoids that are behaviorally and ecologically similar may differ in their ability to utilize the same hosts.



Species 1: Hymenoptera Pteromalidae Anisopteromalus calandrae
Species 2: Coleoptera Anobiidae Lasioderma serricorne (Cigarette beetle)
Species 3: Lepidoptera Gelechiidae Sitotroga cerealella (Angoumois grain moth)
Keywords: Biological control, Stored product pest

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