USE OF TEMPERATURE ACCUMULATIONS AND SEQUENTIAL SAMPLING IN PREDICTING DAMAGING POPULATIONS OF BLISSUS-LEUCOPTERUS-HIRTUS HEMIPTERA, LYGAEIDAE

The initiation of post-diapause development in Blissus leucopterus hirtus was marked by oogenesis in overwintered females. Its temperature threshold was established as 7°C. Sequential sampling and chemical applications were timed from a knowledge of day degrees accumulated above this threshold to the peak in numbers of 3rd-instar nymphs. The sequential sampling scheme was developed to identify injurious infestations of B. I. hirtus and to recommend or advise against chemical treatment. It was based on the size of the population of 3rd-instar nymphs, sampled at their peak, in relation to 2 critical densities. This stage of the insect conforms to a negative binomial distribution with a common it of 0.401. The system proved effective, both in timing and accuracy of prediction, when put into practice on 33 lawns in Guelph, Ontario. © 1979 Entomological Society of America.