Seasonal Dynamics of Aphids and Their Associated Spiders on Two Field Crops at Qalubyia Governorate, Egypt

Abstract

Infestation of the broad bean and maize crop with Aphis craccivora and Rhopalosiphum maidis, respectively at Qaha research station, Qalubyia started in January and May (or June) during two years of study. The monthly collected number and percent abundance of each and total life stage (s) of A. craccivora and R. maidis gradually increased to reach peaks in March (or March and February) and August then decreased in the last month of the season of the broad bean and maize, respectively. Immatures were the most prevalent life stages followed by unwinged and winged adult females. Generally, the total collected number of each life stage of A. craccivora and R. maidis was higher in 2018 than in 2017.A total of 26 spider species belonging to 20 genera and 10 families of order Araneae were associated with the two aphids, A. craccivora and R. maidis, on the broad bean and maize at the site of study in 2017 and 2018. About 50% of the collected species were common spiders associated with each of the two aphid species on its host crop. Generally, the total spiders of the collected families on the broad bean and maize crops started appearing with relatively small numbers in January and May, gradually increased in parallel with those of the associated aphid species to reach peaks in March and August, then the numbers of both were decreased at the end of the crop season in April and September, respectively during each year of the study.