pnut pnut Peanut Science 0095-3679 0095-3679 American Peanut Research and Education Society 10.3146/i0095-3679-5-2-7 Articles Effect of Pesticide Interactions on the Twospotted Spider Mite on Peanuts1,2 W. V. Campbell 3 Professor of Entomology, North Carolina State University, Raleigh, 27650

1Paper Number 5575 of the Journal Series of the North Carolina Agricultural Experiment Station, Raleigh, North Carolina 27650.

2The use of trade names in this publication does not imply endorsement of the products named or criticisms of similar ones not mentioned.

 7 1978 5 2 83 86 16 8 1978 American Peanut Research and Education Society 1978 American Peanut Research and Education Society Abstract

Pesticides commonly applied to the foliage of peanuts in North Carolina were evaluated under field conditions for their effect on the twospotted spider mite Tetranychus urticae Koch. Most fungicides caused a higher mite increase than insecticides on NC 2 peanuts. When fungicides and insecticides were tank mixed or applied on alternate weeks, mite outbreaks occurred. These outbreaks were followed by severe injury to the foliage and finally defoliation and yield reductions.

Among the fungicides applied only Du-Ter and Copper Count failed to cause significant mite damage even when combined with an insecticide. Since mites failed to develop on untreated peanuts following six or more mite releases during the season, it was apparent that pesticides predispose peanuts to spider mite buildup and damage.

 Key Words Twospotted spider mite; , Tetranychus urticae Koch; , Peanuts; , Ground nuts; , Arachis; , Pesticide interactions