Submitted to: Proceedings, IOBC
Publication Type: Abstract Only
Publication Acceptance Date: October 15, 2007
Publication Date: N/A
Technical Abstract: Conditions encountered by insect predators during rearing and shipment are likely to affect their behaviors and efficacy following release. Their age, developmental stage, reproductive status, nutritional and hunger states, sex ratio, etc. will all affect their performance in greenhouse or field. We have been studying the nutritional requirements of Orius insidiosus for peak rates of oviposition. By isolating key nutrients from eggs of one species of prey (E. kuehniella) commonly used for commercial rearing, we hoped to increase reproductive rates while reducing input costs through artificial diet development. Specific proteins isolated from E. kuehniella eggs produced high oviposition rates at low concentrations. These proteins could be enzymatically hydrolyzed without loss of activity. Chromatographic separation of the products of hydrolysis resulted in loss of activity, which could be restored by combined some of the chromatographic fractions. The oviposition assay treated the response of females to nutrients as a “black box”, since our analysis concerned only the final product, the number of eggs laid per 24-hr period. When we altered our methods to enable study of the molecular events between ingestion and oviposition, we found that we could starve females on water or 5% sucrose solution for at least three days prior to feeding them on prey eggs. This allowed predictable timing for feeding, as verified by dissection. The short-term (3-hr period) feeding rate on western flower thrips, Frankliniella occidentalis, was increased by 3- to 4-fold when starved for overnight shipment and assayed 48 hr after starvation began. Thus, starvation during shipment in place of feeding on prey will achieve the highest short-term feeding rate upon receipt and release.