Field Control of Synanthedon myopaeformis Borkh and Zeuzera pyrina L. Using Entomopathogenic Nematodes, Insecticides and Microbial Agents

Abstract

Three field trials were carried out to evaluate the efficacy of two local strains of entomopathogenic nematode, Heterorhabditis bacteriophora ( Ar-4 and Ht strains) isolated from EL-Arish and Giza in Egypt and two commercially available nematode species, Steinernema carpocapsae (All strain) and H. bacteriophora (HP88 strain) for the control of fruit tree borers, Synanthedon myopaeformis and Zeuzera pyrina on apple trees. The entomopathogenic nematodes (EPNs) were used alone or combined with recommended dose of the microbial pesticide, Bacillus thuringiensis (Diple2X), and insecticides, diazinon and phenthoate. The obtained results showed that the combined EPNs with insecticides were more effective as injection technique than spray method. Mortality percentages of S. myopaeformis ranged between 47.61 to 88.88 % in the injection treatments while in the spraying one it ranged between 37.14 to 74.07 %. In comparison between the efficacy of native and imported entomopathogenic nematodes in controlling Z. pyrina using spray technique, percentage mortality resulted from the combination of native nematodes i.e. H.bacteriophora (Ht strain) and H. bacteriophora (Ar-4 strain) and insecticides either penthoate or diazinon reached 69.23; 64.00 and 22.72; 64.18%, respectively. Whereas, percentages mortality were 44.44; 50.00 and 52.94; 54.16% with S. carpocapsae (All strain) andH. bacteriophora (HP88 strain), respectively. The susceptibility of Z. pyrina to the nematode species differed greatly according to the nematode species used either alone or in combination with the recommended dose of B. thuringiensis. The entomopathogenic nematode H. bacteriophora (HP88 strain) was more virulent than S. carpocapsae (All strain) in controlling Z. pyrina with percentage mortality reached 77.5 and 62.1%, respectively