Oviposition and Isolation of Viable Eggs from Orius insidiosus in a Parafilm and Water Substrate: Comparison with Green Beans and Use in Enzyme-Linked Immunosorbent Assay

Abstract Plant parts are commonly used as oviposition substrates for mass rearing of Orius spp., but this system does not permit the isolation of clean intact eggs for use as standards in a yolk protein enzyme-linked immunosorbent assay (ELISA). An oviposition substrate was devised for O. insidiosus by forming water-filled domes from Parafilm-M. Eggs were deposited through the Parafilm skin into water where they remained viable for at least 24 h. Eggs were extracted from the domes and collected onto black filter paper and then used to prepare lyophilized yolk protein as a quantitative standard in ELISA tests. In no-choice tests, O. insidiosus females oviposited 5.86 eggs per female per d into ‘Blue Lake’ green beans, Phaseolus vulgaris L., and 3.06 eggs into water-filled domes. Hatch rates did not significantly differ, although optimal moisture was critical. In a choice test, O. insidiosus females preferred beans to domes (4.02 versus 0.03 eggs per female per 18 h). Females preferred to oviposit into the walls of the major groove of green beans and often oviposited around the lower perimeter of water-filled domes. Lyophilized protein from eggs collected in water-filled domes was successfully and replicably used in the yolk protein ELISA after compensating for reduced immunological activity with a correction factor. Parafilm-covered water-filled domes are therefore useful for collection of eggs for use in the yolk protein ELISA and for other applications that require viable eggs. These domes also may lead to discovery of the phytochemical and physical factors that are responsible for choice of a host plant and its parts for oviposition.