Management of the major piercing sucking pests infesting cucumber under plastic house conditions

Abstract

Evaluation of botanical insecticides namely Nimbecidine at 0.03% azadirachtin and Bio-Catch (Lecanicillium lecanii spores at 1 × 109) for the control of aphids “Myzus persicae (Sulz.)” and the two-spotted spider mite “Tetranychus urticae Koch” was carried out under plastic house conditions. Their activities against aphids and mites were compared with the recommended pesticide “Aphox” in two plastic houses. The adverse effects of the different control agents used were evaluated on the parasitoids present. The results obtained show that spraying cucumber with Nimbecidine followed by Bio-Catch in alternation for four successive sprays achieved good results in decreasing the number of aphids and mites drastically in comparison with the control plants treated with water. Also, both products can be considered as safe biocontrol agents to the parasitoid present in the plastic house as the calculated adverse effect against mummified aphids varied between 18% (harmless) by using Nimbecidine and 26% (slightly harmful) on using Bio-Catch after 7 days from treatment in the last spray. On using chemical insecticide like Aphox for control of aphids, a highly significant reduction in the percentage of living aphids M. persicae was observed while the population of T. urticae is not affected significantly. Also, Aphox can be considered as slightly harmful pesticide for the parasitoid Aphidius colemani present in plastic house for the 1st spray. But repeated application with Aphox for aphids control can be considered harmful where the adverse effect against mummified aphids ranged between 84% and 95% after 7 days from treatment.