ARS | Publication request: LABORATORY REARING PROCEDURES FOR TWO LEPIDOPTERAN WEED BIOCONTROL AGENTS

Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 19, 2005
Publication Date: March 1, 2006
Citation: Raina, A.K., Gelman, D., Huber, D., Spencer, N.R. 2006. Laboratory rearing procedures for two lepidopteran weed biocontrol agents. Florida Entomologist 89:9-96.

Interpretive Summary: Exotic knapweeds are very destructive invasive species that have established in range lands of several Midwestern states. Use of biological control agents such as larvae of moths against these weeds is feasible if the insects could be mass produced. Therefore there was a need to develop artificial rearing procedures for these biocontrol agents. We developed rearing techniques using artificial diets for two exotic species of moths. Preliminary results indicated that both species were able to complete their development on these diets. The information would become the basis for further improvement of the rearing techniques so as to produce large number of these beneficial insects for biological control of weeds.

Technical Abstract: Laboratory rearing methods for Pterolonche inspersa (Lepidoptera: Pterolonchidae) and Agapeta zoegana (Lepidoptera: Tortricidae) were developed. These species have been introduced into North America for the control of the exotic knapweeds, Centaurea spp. We used known diets for the pink bollworm Pectinophora gossypiella (same superfamily as P. inspersa) and Eastern spruce budworm Choristoneura fumiferana (same family as A. zoegana) and added 2% knapweed root powder to these. Of the 3 rearing containers tested, 30ml clear plastic cups with paper lids provided the best results. Root powder was required to induce larval feeding. After 45-50 days, we obtained 4th and 5th instar larvae for both P. inspersa and A. zoegana, apparently either averting or shortening the diapause in some cases. Remaining larvae were refrigerated for normal diapause development. Resulting moths produced a small F2 generation. Suggestions for further improvement of the rearing methodology are discussed.