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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Invasive Insect Biocontrol & Behavior Laboratory » Research » Research Project #427308

Research Project: Investigation of the Symbiotic Polydnavirus Role in Speciation of Braconid Wasps and Caterpillar Host Modification

Location: Invasive Insect Biocontrol & Behavior Laboratory

Project Number: 8042-22000-291-04-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Aug 7, 2014
End Date: Sep 30, 2018

Objective:
To define molecular genetic factors of a symbiotic parasitoid polydnavirus that allow the parasitoid to modify insect hosts and adapt to new hosts; these could be exploited for biological control and could represent novel genetic targets for molecular biopesticides based on RNA interference.

Approach:
The Cooperator will evaluate the influence and role in speciation on different caterpillar pest hosts of a parasitoid wasp polydnavirus and in different ecological situations, and the interactions and changes that occur in the polydnavirus when on different hosts that contribute to their effectiveness and potential use in biocontrol. The project will test the following hypotheses as related to Lepidopteran insect hosts (Ceratomia catalpa, Manduca sexta (model system), and other lepidopteran insect pests parasitized by parasitoid wasp Cotesia congregata: (1) Barriers to reproduction between different host/food complex sources of the parasitoid C. congregata will vary with respect to host divergence; (2) Parasitoid polydnavirus genes are altered in the process of parasitoid adaptations to new host species or host food-plants; and (3) Inviability of certain Cotesia parasitoid F2 generation parasitoid hybrids is due to a non-functional interaction of polydnaviral production machinery genes. ARS will develop high throughput transcriptomes of genes encoded by a parasitoid polydnavirus and evaluate their differential expression on each of three different caterpillar agricultural pests. Potential gene targets for RNAi will be identified in the caterpillar pests that may be exploited for their biological control.