Sirota, J. M. 1990. The temporal and spatial distribution and sex ratio of summer adults of the seven spotted ladybird beetle (Coccinella septempunctata L. Coleoptera: Coccinellidae) in alfalfa. Thesis, Michigan State University, East Lansing, Michigan, USA.
Yellow sticky traps and quadrat observations or hand collected samples were used to examine the temporal and spatial distribution, and sex ratio of Coccinella septempunctata L. (C7) summer adults. C7 was univoltine, with activity starting in March, eggs and larvae produced in May and early June, and summer adults emerging in mid-June. Emigration to hibernation sites most likely occurred during late July and August. None of the weather factors measured were consistently associated with C7 activity. C7 showed a clumped spatial distribution in traps which was probably due to the attractiveness of traps. A random distribution in quadrats was accepted because there is no biological reason for interaction between individuals during summer. Sex ratio of hand-collected beetles was 1:1. A slight change in sex ratio in traps occurred during late summer. Males were captured on traps more often at the end of July and early August, and more females were captured later.back to index