Biology of Cybocephalus sp. nr. nipponicus (Coleoptera: Cybocephalidae), a natural enemy of euonymus scale (Homoptera: Diaspididae)

Cybocephalus sp. nr. nipponicus Endrody-Younga was introduced into the United States as pare of a biological control project against euonymus scale, Unaspis euonymi (Comstock). knowledge of the biology of cybocephalid species is very limited. At 22 degrees C, C. sp. nr. nipponicus had a generation time of approximate to 7 wk from egg to newly emerged adult, and adults lived for 11-14 wk. Cybocephalus sp. nr. nipponicus is able to pupate both in the soil and under scale covers. The total number of eggs laid per female averaged 288.6 +/- 236.5 eggs. Variation in total life time fecundity (19-589) depended on female lifespan. Beetles lay eggs under scale covers; larvae penetrate under scale covers to eat scales, consuming an average per lifetime of 19.5 +/- 11.4 scales. Younger scales are consumed by larvae in larger numbers. Predation rates by adult C. sp. nr. nipponicus beetles were affected by both the number and age of scales in local patches. Both the number and percentage of scales attacked by adult beetles increased with increasing scale age. Adult beetles consumed 4.5 times more euonymus scales than San Jose scales, Quadraspidiotus perniciosus (Comstock), with high consumption rates of 2-stage male euonymus scales.