. Beneficial insects and mites. Mites; Pests; Insects. Figure 3. The convergent lady beetle, Hippodamia convergens. A) Larva. B) Pupa. C) Adult. mountain ranges. These California beetles are har- vested from their overwintering sites, stored at cool temperatures to maintain their dormant state, and shipped to customers in the spring and summer for release in gardens or crops. A common problem that limits the usefulness of convergent lady beetles is that they fly away soon after being released. In California, when converg- ent lady beetles emerge from their overwintering sites in the foothills,
. Beneficial insects and mites. Mites; Pests; Insects. Figure 3. The convergent lady beetle, Hippodamia convergens. A) Larva. B) Pupa. C) Adult. mountain ranges. These California beetles are har- vested from their overwintering sites, stored at cool temperatures to maintain their dormant state, and shipped to customers in the spring and summer for release in gardens or crops. A common problem that limits the usefulness of convergent lady beetles is that they fly away soon after being released. In California, when converg- ent lady beetles emerge from their overwintering sites in the foothills, they disperse, seeking feeding and reproduction sites where aphids or some other suitable prey are abundant. Convergent lady bee- tles harvested in California and released in Midwest gardens retain this natural tendency to disperse, making them poorly suited for small-scale releases. Field-scale or community-wide releases of converg- ent lady beetles for control of heavy aphid out- breaks are likely to be more useful than backyard garden releases for control of minor pest problems. Convergent lady beetles provide long-term, ade- quate aphid control in a release area only if they reproduce. Several factors influence reproduction. Adult female beetles harvested from overwintering sites cannot produce eggs until they have fed on prey. In addition, they lay their eggs only where prey are abundant enough to sustain the resulting larvae. Because adults are able to fly, they tend to disperse in search of more abundant prey when aphid populations fall below a critical threshold. If they disperse without laying eggs, the aphids that are left behind may build up to damaging levels. If the lady beetles lay eggs before dispersing, the resulting larvae continue to control aphids when the adults are gone. Larvae provide better aphid con- trol than adults because they cannot fly away when aphid populations are low. Despite problems with dispersal, the convergent lady beetle is widely adverti
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Keywords: ., bookauthorillinoisnaturalhi, bookcentury1900, booksubjectinsects
