Population Density of Piercing-Sucking Pests and their Associated Natural Enemies on Pepper, Capsicum annuum L. Plants under Greenhouse Condition at Ismailia Governorate, Egypt

 
This study was conducted on pepper plants, Capsicum annuum L under greenhouse condition,in the farm of El Qassaseen Horticulture Research Station, Ismailia Governorate during the two successive winter seasons of 2013/2014 and 2014/2015 to survey the main piercing-sucking pests and associated natural enemies, also determine the population density and occurrence percentage for main species of pests and associated natural enemies. The obtained results showed that, the homopterous insects were the dominant piercing – sucking pests recorded 85.87 % (at the 1^st season) followed by order Acarina family Tetranychidae (the two spotted spider mite, Tetranychus urtica Koch.) recorded 14.32 % (at the 2^nd season), but the order Thysanoptera, family Thrpidae (Onion thrips, Thrips tabaci Lind.) was occurred by lowest occurrence percentage 2.82 % of the total numbers of surveyed pests recorded at the 2^nd season. While the Aphididae was the dominant homopterous family presented with 80.96 % (at the 1^st season) of the total surveyed pests with three aphid species (green peach aphid, Myzus persicae (Sulz.), potato aphids, Macrosiphum euphorbiae (Thomas) and cotton aphids, Aphis gossypii Glov.), the Cicadellidae recorded lowest percentage of 0.99 % at the1^st season. The M. persicae found colonized plants terminals with high percentage of 72.80 % than on leaves by 27.20%; in contrast with M. euphorbiae which recorded 83.85% on leaves and 16.14% on terminals, while A. gossypii found on flowers only. The highest peak (as grand mean of the three aphid species) of 165.67 individuals /plant was recorded at 11^st March during the 1^st season. The highest parasitizem percentage on aphid species of 85.00 % was recorded at 22^nd June during the 2^nd season. The highest peaks for whitefly, Bemisia tabaci (Genn.) of 12.00 individuals / leaf were recorded at 8^th February and 16^th June during the 2^nd season. The leafhoppers, Empoasca spp. gave two weak peaks throughout the short activity period during the two study seasons. In the same trend, the population of T. tabaci recorded relatively high peak of 7.00 individuals/ leaf at 22^nd April during the 1^st season. Also, the T. urtica recorded the relatively high peak of 30.33 individuals/ inch² at 22^nd April during the 1^st season. The highest peak of the general mean of insect predators (Coccinella spp. and Syrphus spp.) and that of grand mean of insect plus mite predators were recorded at 25^th March with 22.00 individuals/plant and 25.67 individuals/plant throughout the 1^st season for the two means, respectively . The peaks of predators were congruent in time with high activity period of pests that may be play main role in suppress piercing-sucking pests. The statistical analysis results showed that, the highest effect as explained variance, EV % = 67.92 and 59.94 % were recorded for the effect of each of parasitoid and total insect predators on aphids species during the 1^st season. So, it could be recommended to use each of parasitoids and predators to control piercing-sucking pests in greenhouses