ADAPTATION OF RODOLIA-CARDINALIS (MULSANT) (COL, COCCIOELLIDAE) TO ICERYA-AEGYPTIACA (DOUGLAS) (HOM, MARGRODIDAE) AS COMPARED WITH ICERYA-PURCHASI MASK

The Coccinellid beetle, Rodolia cardinalis (Mulsant), was introduced i nto Egypt in 1902 to control Icerya purchasi Mask. Developmental stage s of R. cardinalis have been found to be associated with populations o f Icerya aegyptiaca (Douglas) on Ficus nitida trees in the Mansoura di strict of Egypt. The present work throws more light on the adaptation of this predator when feeding on Icerya aegyptiaca as compared with fe eding on I. purchasi. Choice of prey type was found to have a marked e ffect on egg coloration but appears to have no effect on hatching succ ess or incubation period. The development of R. cardinalis larvae when reared in culture on I. aegyptiaca was significantly faster than that fed on I. purchasi. The fecundity of R. cardinalis females was not af fected by the prey type consumed as adults, and although the longevity of males and females was shorter in association with I. purchasi, thi s difference was not significant. The results indicate that R. cardina lis is well adapted to I. aegyptiaca in Egypt.