Abstract

The present study was carried out throughout two successive growing seasons (2018/2019 and 2019/2020) at Mansoura district, Dakhlia Governorate, Egypt, to study the performance of some tomato cultivars to infestation by the cotton aphid, Aphis gossypii (Glov.) (Hemiptera: Aphididae) and their spatial distribution patterns. The obtained results showed that insect population of A. gossypii occurred on all different tomato cultivars all the season round. These varieties varied significantly in their susceptibility to population density of A. gossypii. Hybrid T4 84 tomato cultivar was the highest population density and was rated as highly susceptible (H.S.) to infestation by the total population density of A. gossypii, followed by Hybrid T4 70 and Fiona cultivars were appeared as susceptible (S), while, Maram and Rawan cultivars were observed to be relatively resistant (RR). But, Beto 86 cultivar had the lowest population density and was rated as relative resistant (MR) of pest over the entire season. These pieces of information can be useful for establishing IPM strategies against this pest. Data were analysed using twenty two distribution indices. All distribution indices indicated significant aggregation behaviour during each growing season in all the tested tomato cultivars. This study may be add some information to be used in integrated pest management programs for controlling the aphid on tomato plants