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Delphastus pusillus is a specialized whitefly predator in the lady beetle family. The adult beetles can fly, while larvae are slow moving and travel from plant to plant on leaves. Adults are tiny, 1/15th in. long, dark brown to black in color, and hemispherical in shape. Females have reddish-yellow heads, which are lighter than males. Larvae are elongated, cream colored, covered with short fine hairs, and have conspicuous legs. Plants with trichomes (hairs) may deter feeding and egg laying of Delphastus. Native to the Eastern United States.
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Delphastus is used to control whiteflies in tropical plantings and in commercial greenhouses. Delphastus avoids feeding on parasitized whiteflies and is therefore compatible with Encarsia and Eretmocerus, two whitefly parasitoids. Delphastus adults are strong flyers and will migrate to high density whitefly populations, while parasitoids do best at lower densities of whiteflies. The adults prefer feeding on whitefly eggs and nymphs. Delphastus do not survive in the absence of prey, therefore should be released only after whiteflies are detected. Works best in temperatures between 65F and 90F with rH over 75%. Release in early morning or evening.
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Development from egg to adult takes 3 weeks at 80F. Female adults then live for about 50 days and lay approximately 3-4 eggs/day.
Eggs are clear ovals, laid on the end in clusters on the underside of leaves. Females lay 2-6 eggs per day, and can lay over 300 eggs in their 65-day life time. Females must eat 100-150 whitefly eggs per day to initiate and sustain egg laying. Larvae feed for 7-10 days. Older larvae migrate down the plant to pupate in plant stalks or dried up leaves. Pupae are often found clustered along leaf veins on the undersides of leaves. Adults emerge from pupae in 6 days and are pale in color but eventually turn black. Both larvae and adults are active predators and can consume over 300 eggs or 100 nymphs of silverleaf whitefly per day.
A single beetle can consume as many as 10,000 whitefly eggs or 700 larvae during its lifetime. If food is scarce, they will also feed on other small arthropods, such as spider mites and aphids, and will cannibalize their own species.
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0.5-1.0 predators per sq. ft. Once the beetles warm up they become active immediately. Release as soon as possible upon receipt. If necessary store for 1-2 days at 50-61F. Longer storage will reduce egg laying.
