Physiological effects of entomopathogenic nematodes Steinernema carpocapsae and Heterorhabditis bacteriophora on the adult grasshopper Heteracris littoralis (Acrididae: Orthoptera)

Abstract

A current study was carried out to evaluate one of the important biological control methods in the management of grasshoppers, Heteracris littoralis (Rambur) (Acrididae: Orthoptera) which infesting many different plants through artificial infestation by two entomopathogenic nematodes (EPN); Steinernema carpocapsae (Weiser) (Rhabditida: Steinernematidae) and Heterorhabditis bacteriophora (HP88) (Rhabditida: Heterorhabditidae) in the physiological laboratory, and noticing its physiological effects on the physiological characteristics of grass hopper H. littoralis adults. Whereas current laboratory experiment was carried out through four doses of two tested entomopathogenic nematodes species; S. carpocapsae and H. bacteriophora; 200, 300, 400, and 500 IJs/100 ml.H2O at 25°C and 60% humidity for 72 hrs. Results obtained indicated that as general effectiveness of H. bacteriophora was higher than the other S. carpocapsae on the physiological characteristics of the successive grasshopper H. littoralis. Also, the higher doses of both of the EPNs were more effective on these physiological characteristics than the lower doses. Physiological characteristics of grasshopper H. littoralis were examined stimulated in the most internal substances secreted by that insect; Total proteins, carbohydrates, total lipids, and important enzymes (Chitinase, lipase, phosphatase, kinase, alpha esterase, beta esterase, oxidation enzymes and digestive enzymes).