Delphastus catalinae (Horn)
(Formerly known as Delphastus pusillus (LeConte))
Common name: Whitefly predator, sweet potato whitefly predator.
Geographic distribution: This beetle, of American origin, is now distributed in most parts of the world through commerce.
Morphology: Adult beetles are small, body hemispherical, about 1.4 mm in length, shiny dark brown to black. Head brown and legs reddish. The larvae are elongate, green-yellow, with many setae.
Life history: The larvae and adults are predators of whiteflies. A complete life cycle takes 21–25 days. The eggs are laid in clusters of prey eggs on the underside of leaves. The females produce 2–6 eggs/day, and can lay over 300 eggs during their 2 months lifetime. They pupate on lower leaves or in various protected locations. Optimal condition are between 18°C-30°C, and lower temperatures delay development; the threshold of development was calculated to be at 10°C. Whitefly honeydew can sustain the predator during periods of low prey populations. The beetles are strong fliers that search for and can locate plants with large whitefly colonies. The larvae and adult beetles avoid feeding on parasitized whitefly nymphs.
Economic importance: Delphastus catalinae is an efficient predator of whiteflies and is sold by various insect-rearing companies (e.g., by Koppert as “Delphibug” for whitefly control). Due to their avoidance of parasitized whiteflies these predators can be applied against the pests together.
Effect of pesticides: Pyrethrin and insecticidal soap reduced D. catalinae numbers for 1-3 days, but had no effect after 5 days. Applications of the Entomopathogenic fungus _ Lecanicillium lecanii_ R. Zare & W. Gams against the whitefly Trialeurodes vaporariorum resulted in reduced consumption of the infected whitefly prey.
Guershon, M. and Gerling, D. 2006. Effects of plant and prey characteristics on the predatory behavior of Delphastus catalinae. Entomologia Experimentalis et Applicata 121: 15-21.
Hoelmer, K.A. and Pickett, C.H. 2003. Geographic origin and taxonomic history of Delphastus spp. (Coleoptera: Coccinellidae) in commercial culture. Biocontrol Science and Technology 13: 529-535.
Kutuk, H. and Yigit, A. 2007. Life table of Delphastus catalinae (Horn) (Coleoptera: Coccinellidae) on cotton whitefly, Bemisia tabaci (Genn.) (Homoptera: Aleyrodidae) as prey. Journal of Plant Diseases and Protection 114: 20-25.
Legaspi, J.C., Legaspi, B.C. Jr., Simmons, A.M. and Soumare, M. 2008. Life table analysis for immatures and female adults of the predatory beetle, Delphastus catalinae, feeding on whiteflies under three constant temperatures. Journal of Insect Science 8: 7.
Pérez, R., Garcia-Gonzalez, J. and and Cotes, A.M. 2008. Efecto de un bioplaguicida sobre la actividad depredadora de Delphastus pusillus (Coleoptera: Coccinellidae). Revista Colombiana de Entomología 34: 176-181.
Razze, J.M., Liburd, O.E., Nuessly, G.S. and Samuel-Foo, M. 2016. . Evaluation of bioinsecticides for management of Bemisia tabaci (Hemiptera: Aleyrodidae) and the effect on the whitefly predator Delphastus catalinae (Coleoptera: Coccinellidae) in organic squash. Journal of Economic Entomology 109: 1766-1771.
Simmons, A.M., Legaspi, J.C. and Legaspi, B.C. Jr. 2012. Adult survival of Delphastus catalinae (Coleoptera: Coccinellidae), a predator of whiteflies (Hemiptera: Aleyrodidae), on diets of whiteflies, honeydew, and honey. Environmental Entomology 41: 669-75.