| Abstract: | The incidence of parasitism and disease in third-instar and adult Ceroplastes destructor Newstead and C. sinensis Del Guercio (Hemiptera: Coccidae) on citrus in Northland, New Zealand, was measured from 1991-1994. Both species were parasitized by female Euxanthellus philippiae Silvestri (Hymenoptera: Aphelinidae). Female E. philippiae were hyper-parasitized by males of their own species and by Coccidoctonus dubius Girault (Hymenoptera: Encyrtidae). Male E. philippiae were also tertiary parasitoids of C. dubius. E. philippiae was found in third-instar and adult C. sinensis , but was virtually restricted to third-instar C. destructor . Parasitoid phenology varied according to the instar and species of the host. Two fungal pathogens, Verticillium lecanii (Zimmermann) Viegas and Fusarium spp., were identified from both C. destructor and C. sinensis . Disease was a greater mortality factor than parasitism in C. destructor , whereas the opposite applied to those C. sinensis for which the cause of death could be identified. Disease levels were underestimated, particularly in C. destructor. Mortality from parasitism and disease did not act in a density-dependent manner. |
