Effects of different feeding density on development of German cockroach reproduction capacity

ObjectiveTo find out the reproduction condition of German cockroach at different feeding density.MethodsTo set up five different densities and three different sex ratios.Repeat three times.To observe mating,fecundity,hatching, the weight of the first age larva and sex condition at different feeding density.ResultsThe fecundity was maximum at a low density(in the experiment German cockroach was 20 and 40).As the increase of density,the fecundity decrease,female had an important role in hatching athigh density.As the increase of density,the weight of the first age larva became decreasing-tendency and the offspring number of one female decreases,nevertheless,when the density increased to a certain degree,the offspring number had little difference.The relationship between weight and feeding density met the Logistic equation:W=K/1+e^a+rρ(W:stands for weight of larva, ρ:feeding density K:environmental capacity).The sex ratio of offspring had little difference with the sex ratio and density of parent.ConclusionUnder the limited resource of foods and space,as the variety of density,the reproduction capacity of German cockroach has certain adjust capacity.Decreasing habitathas an important role in the control of German cockroach.