Efficiency of Entomopathogenic Nematode and One Insect Growth Regulator, as a Biocontrol of Diamond Back Moth (Plutella xylostella L.), and Their Toxicity to Participate Predators at Cabbage Fields

Diamond back Moth (DBM), Plutella xylostella L. is one of the economically important insect pests that destroy cabbage crops in most countries of the world. The target of the present study was to examine the potency of gamma radiated nematodes, normal nematode Steinernema carpocapsae BA2, and insect growth regulator, Match 5%EC as alternative control methods for P. xylostella larvae compared with conventional insecticides (radiant and radiant mixture with match), as well as to examine their safety on P. xylostella predators inhibiting cabbage plants. This experiment was carried out at El-Riad District, Kafr El-Sheikh Province in 2020 and 2021 seasons. The results revealed that plants treated with irradiated nematode in rate of 120 IJ's +2 Gy / ml hosted the fewest number of P. xylostella larvae compared to the untreated plants with a significant reduction of 98.05% and 98.81% during 2020 and 2021, season. Further, 2 Gy irradiated S. carpocapsae BA2 was more potency in reducing numbers of insect larvae than normal nematodes and other treatments. Gamma irradiated nematodes at rate of 120 IJ's +2 Gy / ml seems to be the most auspiciously agents against P. xylostella. While insect growth regulator Match 5% gave overall average of 76.52 and 76.42% mortality in the two seasons, respectively. The 2 Gy irradiated S. carpocapsae BA2 and normal nematode were safe on P. xylostella predators on cabbage plants, whereas chemical insecticides reduced numbers of predators