maculata females must touch or taste DHBA to stimulate oviposition. We tested the hypothesis that 2,4-dihydroxybenzoic acid (DHBA), an inexpensive degradation product of morin (a flavonol bioflavonoid), stimulates oviposition by the ladybird beetle Coleomegilla maculata (DeGeer). The discovery of inexpensive, readily available bioflavonoids, and their degradation products that boost the reproductive potential of mass-reared predators is the overarching goal of this research. Future research should determine if quercetin stimulates oviposition in other ladybird beetle species. This study provides evidence that quercetin can be utilized as an oviposition stimulant by C. Females “rested” on the tissue in the presence or absence of quercetin. In one of two experiments, they produced more egg clutches, regardless of oviposition site, when the quercetin and tissue were in close juxtaposition. When given a choice, females oviposited in the dish with quercetin over a tissue paper substrate. We conducted bioassays in solitary cages (housing one female) and communal cages (housing 10 females) to estimate daily oviposition site preferences, egg production in response to quercetin in the presence or absence of a tissue paper substrate, and female “resting” positions.įemales preferentially oviposited within 1⁻2 cm of quercetin powder, held in a tiny dish, at the base of cages. We tested the hypothesis that quercetin (a bioflavonoid) stimulates oviposition by the ladybird beetle Coleomegillamaculata in the presence of conspecifics and a tissue substrate. The discovery of natural products to improve the reproductive performance of mass-reared predators is an important aim for successful augmentative biological control. Techniques for successful rearing of these two coccinellids and future research regarding adaptations to fur- ther optimize their rearing methods are discussed. Over 80% of egg clutches were deposited by beetles on rumpled paper towels versus other surfaces within cages, and incidence of cannibalism of egg clutches was greatly reduced on rumpled paper towels. Adults were housed in cages stocked with live pea aphids, supplemental food, and rumpled paper towels as oviposition substrate. Newly emerged adults were collected within containers about 2 d after eclosion. Upon pupation, individuals were collectively trans- ferred to fresh cups and placed in a different container for the duration of pupation. Third and fourth instars were also fed pea aphids, but reared individually in small cups to preclude cannibalism. Neonate larvae were fed live bird cherry-oat aphids (Rhopalosiphum padi (L.)) for 3 to 4 d, and second instars were trans- ferred to different cages and fed live pea aphids (Acyrthosiphon pisum (Harris)). Eggs were collected every 1 to 2 d and placed in holding containers, and individual clutches were transferred to cages with prey when their eggs began to hatch. The two coccinellid species were each reared separately, and different life stages were handled independently. All rearing of lady beetles was conducted in the laboratory at or near room temperatures and 16:8 L:D photoperiod. An ex situ system for continuously rearing these two beetles is described here to aid conservation efforts and facilitate studies aimed at determining factors in their decline and possible recovery. Coccinella novemnotata L., the ninespotted lady beetle, and Coccinella transversoguttata richardsoni Brown, the transverse lady beetle, are predatory species whose abundance has declined significantly over the last few decades in North America.
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