[The dependence of egg-laying activity on the number of Leptopsylla segnis (Siphonaptera: Leptopsyllidae) fleas on the host].

The egg-laying activity in the fleas Leptopsylla segnis Schonherr declined when their number on the host (white mouse) was risen from 2-5 to 20. However, if the number of the parasites on host exceeded 30 the egg output per female increased. It is supposed, there is an density-dependent regulation of egg-laying activity in L. segnis, which operates in certain diapason of flea abundance. It appears that mechanism of this regulation is suppressed by heavy infestation.