الفهرس 
Whitefly, Bemisia tabaci (Genn.)Only 14 pages are availabe for public view
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Abstract
All field experiments were carried out at the experimental farm of br Shandaweel Agricultural Research Station at Sohag Governorate, during two br successive growing cotton seasons of 2010 and 2011 to survey arthropods, br monitor population fluctuations of certain insects, as well as, their associated br natural enemies. br Biological control of cotton bollworms infesting cotton plants using br Trichogramma evanesces and three predators i.e, Coccinella undecimpunctata, br Coccinella septempunctata and -#99;-#104;-#114;ysoperla carnea were evaluated, also its br effects on cotton yield was determined. Effect of the three previous predators br release on Aphis gossypii population was studied. To study the larval duration, br predation efficiency and handling time of Coccinella undecimpunctata, br Coccinella septempunctata and -#99;-#104;-#114;ysoperla carnea on Aphis gossypii, three br laboratory experiments were conducted in Insectary of Plant Protection br Department, Shandaweel Agricultural Research Station, Sohag Governorate. br The obtained results could be summarized as main points as follows: br 5.1. Survey of certain arthropods associated with cotton cultivation at br Sohag Region, upper Egypt: br Arthropods collected -#102;-#114;-#111;-#109; the cotton plants revealed the occurrence of 24 br species related to 19 families, belonging to 10 orders. Phytophagous species br were represented by 7 important economic insects, (29.16%) and 6 insect br species as non-pest (25%). 2 species (8.33%) were classified as pollinators and br visitors. Natural enemies, parasites and predators were represented by 9 species br (37.5%). br 5.2. Population fluctuations of certain cotton pests and their natural br enemies:- br A. Pests of cotton plants: br 5.2.1. The cotton aphid, Aphis gossypii (Glover.): br The cotton aphid, A. gossypii population showed 3 peaks during the two br successive seasons. Peaks were detected on May 4th, July 27th and August 24th br during 2010 season, and on May 11th , August 3rd and August 24th during 2011 br season. The mean population density over the two cotton seasons showed that br the A. gossypii was detected throughout April. The densities were moderate br during April, May, June and September and high during July and August. br However, the highest aphid population density was obtained during August 24th br for both of the two growing seasons. br 5.2.2. The green leafhopper, Empoasca spp.: br The green leafhopper, Empoasca spp. exhibited three and four peaks in br 2010 and 2011 seasons, respectively. The peaks of 2010 were detected on May br 18th, July 13th and August 10th. As for 2011 season, the peaks were recorded on br May 25th, July 20th, August 3rd and August 31st. Over the two seasons, it could br be concluded that population densities of Empoasca spp. were found in low br numbers during April and June and in high numbers during May, July, August br and September. br 5.2.3. The cotton thrips, Thrips tabaci Lindeman: br Population of T. tabaci exhibited two peaks of activity throughout the br two seasons, 11th and June 15th during 2010 season and on May 18th and June br 15th during 2011 season. The results clearly indicated that the population br densities of T. tabaci were high during May and June, moderate during April br and July and rare in August and September.