Mohammed E. M. A. Hegab*(1) Ahmad A. T. Zaki(1) Ali A.A. El-Sayed(1) and Adel A. Amer(1)
(1). Plant Protection Research Institute, Agriculture Research Center, Dokki, Giza, Egypt.
(*Corresponding author: Dr. Mohammed E. M. A. Hegab. E-Mail: firstname.lastname@example.org).
Received: 15/03/2020 Accepted: 12/05/2020
Field experiments were conducted at ALZagazig Al-Sharkia Governorate during 2017 cotton season to tested some chemical insecticides on the larvae of Pectinophora gossypiella cotton bolls. Three insecticides of Chlorpyrifos+Chlorfluazeron then Lambda-Cypermethrin and then Chlorpyrifos) on P. gossypiella, certain sucking pests, (Aphis gossypii, Bemecia tabaci, Empoasca spp., Nezara veridula and Tetranychus spp.) and their associated predators, (Coccinella spp., Chrysoperla spp., Peaderus alferii, Scymnus spp., Orius spp. and true spiders). The resultes showed that 1st spray was moderately effective on P. gossypiella larvae and recorded 67.33 % reduction after 2nd week while, the highest reduction was 85.71% after 2nd week of 2nd spray. The seasonal mean of reduction was 73.89% after the three sprays. In case of studying the effect of pesticides used to control pink bollworm and its effect on sucking piercing pests. Also, data revealed that the 1st spray was the preferable spray on Tetranychus. spp. and Aphid gossypii attained (100 and 87.79 %), respectively. while in the case of the 2nd spray the effect were noticed on A. gossypii, Tetranychus. spp. and Empoasca spp., which attained (100, 53.40 and 56.20 % ). While the 3rd spray recorded the high mean of reduction percentages on N. veredula and A. gossypii attained (92.15 and 84.16 %). The seasonal mean of reduction percentages after the three sprays can be arranged as follows: (90.65, 79.82, 71.52, 58.56 and 36.49 %) of A. gossypii, N. veredula ,Tetranychus. spp., B. tabaci and Empoasca spp., respectively. On the other hand, the effect of the tested compounds on Chrysoperla spp. were 53.72, 8.23 and 9.39 % reduction recorded after the three sprays, respectively. The obtained results cleared that the tested predators affected on all sucking pests population numbers and recorded the lowest seasonal mean 23.78 % which recorded on Chrysoperla spp. On the other side there was found a relationship ranged between positive & negative and insignificant between Coccinella spp. and the sucking pests, and the relationship was positive and significant with Empoasca spp. In the case of the Chrysoperla spp., the relationship was, and significant with Empoasca spp., N. veridula and Tetranychus spp. numbers. Whereas in the case of Scymnus spp., the relationship was positive or negative and significant in the case of B. tabaci, N. veridula and truespider mites. At the same time, the relationship between Orius spp. beetles and sucking piercing pests ranged between positive & negative, significant and insignificant, and that relationship was significant and negative true spiders and insignificant & positive with other insect piercing insects. Generally, multiple regressions between the sucking pests and predators were 65.19, 72.24, 55.75, 71.45 and 41.56 for (Coccinella spp., Chrysoperla spp., Peaderus alferii, Scymnus spp., Orius spp. and true spiders), respectively. It could be concluded that the treatment of pink bollo worm using the following pesticide program (Chlorperifos + Chlorfloiseron and then Lambadacyhalothrin alone and then Chlorperifos alone) led to a significant reduction in the number of pink bolloworm, pests associated with this effect were low on insect predators associated with perforating sucking insects in cotton fields..
Key words: Pectinophora gossypiella, Insecticides, Sucking pests, Predators.
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