Biology and food spectrum of Seven- spotted ladybird, Coccinella septempunctata L. (Col.: Coccinellidae), in alfalfa fields of Badjgah area (Shiraz)

Seven- spotted ladybird (Coccinella septempunctata L.) is a common and widespread natural enemy in the agroecosystems that serves as an important biocontrol agent against harmful aphids on various crops. This research was conducted to study the biology and feeding diversity of C. septempunctata in alfalfa fields of Badjgah area, located at north of Shiraz. This was done during 2013-14 by sampling from the fields using a standard sweep net. Population changes were recorded weekly and midgut contents of adult beetles were also determined for each month. Based on the results, C. septempunctata had three generations per year in Badjgah area. Overwintering of Seven- spotted ladybird under the environmental conditions of Badjgah started at early November. Studies conducted on the food composition of adult ladybirds in this area revealed that aphids represented main proportion of the total diet in April and May. Decrease in number of aphids afterwards pushed the beetles to feed on Alternaria spores during June and July. In September, when their aestivation terminated, the beetles shifted to available pollens from different plants. Throughout the fall a balanced mixture of spores and pollens composed the metabolic needs and energy reserves for overwintering of the coccinellids.