Arthropods in a Scab, Venturis Inaequalis(Cke.) Wint., (Ascomycetes:Mycosphaerellacea), and European Red Mite, Panonychus Ulmi(Koch), (Acari:Tetranychidae), Resistant Apple Orchard in Indiana

Abstract

Three years of sampling an apple orchard with seven apple scab, Venturia inaequalis(Cke.) Wint., resistant selections, five of which were also resistant to European red mite, Panonychus ulmi(Koch), growing on three different rootstocks (EMVII, MM106, and MM111), showed a faunal composition consisting of nine orders from which 26 families were identified. Two specimens, a homopteran and a lepidopteran, were identified only to order. Seventy-four specimens were identified to genus only, and 59 to species. Three groups (aphids, leaf-hoppers, and ladybird beetles) and nine species of arthopods were found most frequently. Of these the ladybird beetles (grouped together), the green lacewing, Chrysopa carnea(Stephens), and the smooth yellow mite, Zetzellia mali(Ewing), were reported to be beneficial by other investigators. Significant differences (P < 0.05) in the incidence of aphids and codling moth were found between rootstocks and between selections. Similar differences in incidence were found between rootstocks for ladybird beetles and between selections for Z. mali. These data suggest that the spectrum of arthropods found on selections developed through breeding efforts may require a less complicated pesticide protocol for management when compared with that required for cultivated apple cultivars. The protocol may depend on the trait/s for resistance that each selection carries.