An Ecological Study of Arthropod Populations on Apple In Northeastern Wisconsin: Insect Species Present1

Abstract

An ecological study of arthropod populations on apple was conducted in northeastern Wisconsin from 1959 through 1962. Two artificial environments were created in a 3 acre apple orchard by spraying 1 acre with DDT plus captan and a second with captan only at 2-week intervals throughout each growing season. The third 1-acre block was left unsprayed to serve as a natural environment. Populations were surveyed in each environmental block at weekly intervals throughout each growing season, using 6 survey techniques. Insect species discussed in this report were collected by the limb-jarring and spur survey methods. Determinations were made primarily by specialists in the Insect Identification and Parasite Introduction Branch of the United States Department of Agriculture. Fourteen orders, 158 families, 515 genera, anti 763 species of insects were identified from the material collected from the trees. The Hymenoptera was the largest order represented with 28 families, 154 genera, and 263 species. The largest family was the Eulophidae with 22 genera anti 55 species. The largest genus was Tetrasticus, with 10 species. A brief discussion of the possible ecological relationships of the major catagories, and a comparison of the results with other studies was made.