The insect complex of sown pastures in the North Island

Abstract

Techniques developed for the rapid sweep-sampling of pastures are described. One hundred and thirteen sampling stations based on the various pasture types which occur in the North Island were investigated during the summer of 1957. Roadsides adjacent to sampling areas have been studied to determine their possibilities as reservoirs of insects. A general analysis of the insect complex encountered has been made. It is shown that the order of 20 species and 80 specimens per 8 square yards is a common level of occurrence in paddocks and roadsides. Maxima in paddocks of 44 species (excluding Collembola) and 1,300 specimens (excluding Collembola and Thysanoptera) were taken. A population of 2,700 was recorded in the Collembola for one paddock sample. Collembola, Thysanoptera, and Diptera are shown to be present in greatest numbers. Considerable numbers of Hemiptera and Hymenoptera are also present, however, the remaining orders being represented by relatively few individuals. The greatest number of species taken (excluding Collembola) was in the Hymenoptera being followed by the Diptera, Hemiptera, Coleoptera, Lepidoptera, Thysanoptera, Psocoptera, and Neuroptera in that order. Many species are shown to be of widespread occurrence. The majority of the species taken are represented by relatively few individuals. The importance of the species, however, is not necessarily related to its abundance.