On the control of the cotton aphid, Aphis gossypii Glov. (Hemiptera: Aphididae), on cucumber in greenhouses

The objective of this study was to apply a biological control program on cucumber crop under greenhouse conditions, using biological control agents compared with insecticides to control the cotton aphid, Aphis gossypii Glover. The treatments were conducted at Dokki, Giza, Egypt, through two cucumber summer plantations in 2015 and 2016. Inspection was made once a week to determine the population density of A. gossypii, one of the major pests on cucumber. Aphid infestation occurred from week 6 to week 12 in 2015 and from week 4 to week 11 in 2016. Adults of the aphid parasitoid Aphidius colemani Viereck and larvae of the predatory coccinellid, Coccinella septempunctata L., were released in the biological greenhouse in weeks 8, 9, and 10 in season 2015 and 7, 8, and 9 in season 2016. In the insecticide greenhouse, the recommended insecticide program was used. The cost of control in the biological control greenhouses was more than that in the insecticide one, but the yield was much higher, recording 63.88% increase in 2015 and 64.91% in 2016.