Effect of Encarsia sp. nr. diaspidicola (Hymenoptera : Aphelinidae) parasitism on Cybocephalus sp. nr. nipponicus (Coleoptera : Cybocephalidae) egg laying choices

The beetle Cybocephalus sp. nr. nipponicus Endrody-Younga (Coleoptera: Cybo cephalidae) and the wasp Encarsia sp. nr. diaspidicola (Silvestri) (Hymenop tera: Aphelinidae) were introduced from Korea and China into the United Sta tes as part of a biological control project of euonymus scale Unaspis euony mi (Comstock). We report the ability of C. sp. nr. nipponicus to discrimina te between parasitized and unparasitized scales in choosing scales for ovip osition. Beetles avoided ovipositing in previously parasitized scales as so on as 2 days after parasitism. The effects of host age, density, and sex on parasitism levels by E. sp. nr. diaspidicola were also measured. (C) 1999 Academic Press.