SUCCESSFUL PARASITOID CONTROL OF AONIDIELLA-ORIENTALIS (NEWSTEAD) (HEMIPTERA, DIASPIDIDAE) ON CARICA-PAPAYA L

The role of three parasitoids in controlling oriental scale, Aonidiell a orientalis, in papaya in coastal areas of central and northern Queen sland was assessed during 1989-1995. Comperiella lemniscata Compare an d Annecke (Hymenoptera: Encyrtidae) was introduced from Hainan Island in China and from the Torres Strait in northern Queensland, and reared and released in 1991 at the rate of 2000 per property. Within 12 mont hs, parasitisation mainly of the third-instal-scales rose to as high a s 80% and rejection of fruit for the market dropped from 20-30% to 1-2 %. Aphytis melinus DeBach (Hymenoptera: Aphelinidae) was augmentativel y released in papaya plantations in central and northern Queensland at a rate of 25 000 per ha. Parasitisation mainly of the third-instar sc ales was boosted by these releases from 0% to between 10 and 30%, but these levels persisted for only a few months lid the parasitoid had to be continually re-released. Encarsia citrina (Craw) (Hymenoptera: Aph elinidae) occurred naturally at parasitisation levels of up to 80% in mainly the second-instar scales and was important in the biological co ntrol of the scale.