Foliar application of entomopathogenic nematodes for controlling Spodoptera littoralis and Agrotis ipsilon (Lepidoptera: Noctuidae) on corn plants

The cotton leaf worm Spodoptera littoralis and the black cut worm, Agrotis ipsilon (Lepidoptera: Noctuidae) are common destructive pests of many economic vegetable and field crops including corn (Zea mays). They attack the corn seedlings causing damage of the inner whorl leaves and cutting the plant stems above the soil surface. Both insects hide in soil from sun rays and drought or for pupation. Chemical control is used, but with low efficiency. Application of entomopathogenic nematodes (EPNs) for above ground pests is a breakthrough in the field of the bio-pesticides. This work was designed to evaluate the effect of several additives or adjuvants on the performance of two Egyptian isolates of EPNs namely, Heterorhabditis bacteriophora BA1 and Steinernema carpocapsae BA2 in laboratory, semi-field and corn field bioassays against larvae of S. littorallis and A. ipsilon infesting corn plants. Tested adjuvants had no adverse effects against nematode survival or infectivity. Some adjuvants significantly improved the performance of the tested nematodes in both semi-field and field experiments. Combinations of more than one adjuvant were more efficient than single adjuvants. Adding formulation adjuvants to sprayed nematode suspension on corn plants was more effective in case of S. littoralis infesting whorl corn leaves than in case of A. ipsilon attacking bases of corn stems.

Keywords:

Steinernema , Heterorhabditis , Adjuvants