Effect of planting date on seasonal abundance of the Aphis craccivora koch and the associated predators in the new Valley-Egypt

The population density of A. craccivora on broad bean plants of the recommended sowing date fluctuated in scarcely numbers to attain the peak (17.50 and 3.00 individuals/plant) during the third week of November of 2012/2013 and 2013/2014 seasons, respectively. On the other hand, the highest numbers (0.27 and 0.06 individuals/plant) of the coccinellid beetles included the larvae and adults of C. undecimpunctata and C. septempunctata were recorded during the second week of December and the third week of November of the two successive seasons, respectively. There was an insignificant positive and / or negative simple correlation (r) between the number of the pest and the population density of the coccinellid beetles.
The plants cultivated in the early planting date (first of October) harbored the highest number of the pest with an average of (22.72 individuals/plant).  Meanwhile, the plants of the late planting date (end of October) harbored the lowest number of the pest with an average of (2.55 individuals/plant).
Broad bean plants of the early and recommended sowing date which harbored the high levels of infestation with A. craccivora recorded the highyields (gm)/plant. Meanwhile the plants of the late planting date which harbored the minimum number of the pest recorded the lowest yield (gm)/plant during 2012/2013 and 2013/2014 seasons.