Evaluation of certain entomopathogenic nematodes against the melon ladybird,Epilachna chrysomelina F. (Coleoptera: Coccinellidae)

Three native Egyptian nematode isolates; Heterorhabditis taysearae and Heterorhabditis sp. S1 (Heterorhabditidae) and Steinernema carpocapsae S2 (Steinernematidae) as well as H. bacteriophora Hp88 as an imported species, were used in the present work to evaluate their activities against larvae and adults of the melon ladybird, Epilachna chrysomelina. The target pest was found to be susceptible to all tested entomopathogenic nematodes under laboratory conditions of 30±5°C.

In the greenhouse, a single spray of nematode suspension (1000 infective juveniles per ml) of each of H. taysearae, H. bacteriophora Hp88 and Steinernema carpocapsae S2 on squash seedlings was enough to give a reasonable mortality of 4^th larval instar E. chrysomelina, reaching 65.2, 44.0 and 84.0%, respectively, one week after application. This gives evidence that the Egyptian nematode isolates could tolerate high temperature and could be recommended for application in the control programmes of E. chrysomelina larvae in cucurbit fields.