Evaluation of the Effect of Entomopathogenic Nematodes Against Two Instars of The Cotton Leaf Worm, Spodoptera littoralis (Lepidoptera: Noctuidae) Under Laboratory Conditions

Spodoptera littoralis (Lepidoptera: Noctuidae) is one of the important insect pests in Egypt caused damage in cotton and other crops and vegetables. Many agents for controlling this insect pest exist, one of these agents is Entomopathogenic nematodes two families belong to EPNS use controlling that are Heterorhabditidae and steinermatides families, two species were tested Hetrohabditis indica and Steinernema sp under laboratory conditions to Determine their efficacy against the two instars of the cotton leafworm, the consternations of entomopathogenic nematodes were 1000 Ijs and 2000 Ijs for each one. Data indicate that on the 2nd instar high significance on the first, 3rd days 5th days and non-significance on the 7th in EPNs treatment, H. indica caused mortality of 85% for both concentrations on the contrary, Steinernema spp. caused 80% and 100% with concentrations 1000 IJs and 2000 IJs, respectively. On the other hand, the results on the 4th instar showed that mortality percentages were 90% caused by H. indica concentration 1000IJs 75% with concentration 2000 Ijs while Steinernema sp.