Notes on some Coccinellidae (Col.) from Islands in the Indian Ocean

Abstract

This species is found on most of the islands of the Seychelles archipelago including the sand cays of the Amirantes group. It is said to have been introduced about sixty years ago to prey on the Coccid pest Icerya seychellarum, which is reported to have been the most serious pest of coconuts in the Colony at that time. The Icerya is the only prey of R. chermesina, and the latter has evidently kept the former in check on coconut but is unable to prevent occasional damage being done to fruit and other trees. The plants most frequently damaged by Icerya are:—Jak fruit, bread fruit, banana, avocado, citrus and forest tree seedlings, notably Eucalyptus, Albizzia and Casuarina. On certain islands where Rodolia is not present Icerya still occasionally damages coconut. Vedalia cardinalis, the famous predator of Icerya purchasi, also feeds on Icerya seychellarum in captivity, but, to date, liberations have failed to establish this species in Seychelles. Hence R. chermesina remains the most effective known predator of I. seychellarum under Seychelles conditions. No parasites are known from R. chermesina in Seychelles, but the black ant, Technomyrmex albipes, which constantly attends Icerya in large numbers, drives away the Coccinellid.