Populations of aphids, whiteflies and associated predators and parasites on different vegetables cultivated in plastic greenhouses

Abstract

During 1996 and 1997, populations of aphids and whiteflies and their parasites were studied in plastic greenhouses under a chemical control program and in those free of pesticides. In the greenhouses free of pesticides, the parasite A. colemani destroyed 14.7 % of the aphids. B. tabaci had no effect on the cucumbers during the spring cultivation. However, it attacked the autumn cultivation. The parasite E. mundus killed 30 % of these nymphs. The parasite A. colemani parasitized up to 10 % of aphids on tomato plants in greenhouses free of chemical pesticides. The parasite E. mundus killed 15.7 % of whitefly nymphs. In greenhouses under a chemical pesticides program, aphids and whiteflies were found on the plants at the end of the plantation season, after the pesticide spraying had stopped. Although the pest population was low, the parasite A. colemani parasitized 8 % of the aphid population. Whiteflies were not found on tomato plants in greenhouses under extensive pesticides use.

Effect of Planting Dates on Infestation with Certain Pests and Yield of Cucumber Plants During Fall Plantation in Giza Governorate.

“…In other investigation, Abd El-Gawad (2008) indicated that were significant differences between the different planting dates on the infestation by B. tabaci during nili season 2005/2006. While, Ali (1993, El-Khayat et al (1994), Zaki et al (2002) and Esmail (2013). They mentioned that the infestation by B. tabaci occurred on autumn cucumber in September then increased to reach the high level of population in October and November, then declined towards the end of cucumber growing season.…”

Effect of Planting Dates on Major Insect Pests and Yield of Watermelon Seeds (Citrullus lanatus.) in Kafr El - Sheikh Governorate

“…In other investigation, Abd El-Gawad (2008) indicated that were significant differences between the different planting dates on the infestation by B. tabaci during nili season 2005/2006. While, Ali (1993), El-Khayat et al (1994), Zaki et al (2002) and Esmail (2013). They mentioned that the infestation by B. tabaci occurred on autumn cucumber in September the increased to reach the high level of population in October and November, then declined towards the end of cucumber growing season.…”

Susceptibility of Three Cucumber Varieties to Whitefly, Bemisia tabaci Infestation and Impact of Intercropping of Aromatic Plant Against Bemisia tabaci Under Greenhouse

“…These findings are consistent with prior results (Abd El-Gawad 2008), which demonstrated that the B. tabaci infestation during the 2005-2006 Nile season varied significantly depending on the planting date. According to these studies, Ali (1993)., El-Khayat et al (1994), Zaki et al (2002)., and Esmail (2013) found that B. tabaci infestations started in fall cucumbers in September, grew to a high population in October and November, and then started to drop as the cucumber growing season came to a close. Additionally, previous studies by Seham et al 1997;Emam et al 2006;and Shaalan, 2016 came to the conclusion that, like in the current study, the various planting dates throughout the year had an impact on the establishment of a variety of pests, including B. tabaci.…”