Potter Spray Tower Bioassay of Selected Citrus Pests to Petroleum Spray Oil

Abstract

A Potter spray tower was used to determine the relative susceptibility of selected stages of various citrus pests and green peach aphid to petroleum spray oils. the order of decreasing susceptibility, expressed as μg oil/cm2 required to give 95% mortality, was first‐instar Saissetia oleae (Olivier) 41, first‐instar Ceroplastes sinensis Del Guercio 46, adult Myzus persicae (Sulzer) 50, first‐instar Aonidiella aurantii (Maskell) 55, first‐instar C. destructor Newstead 59, first‐instar C. rubens Maskell 59, adult Panonychus citri (McGregor) 71, adult Heliothrips haemorrhoidalis (Bouché) 74, first‐instar Pseudococcus calceolariae (Maskell) 135, adult Tetranychus urticae Koch 166, adult Toxoptera citricida (Kirkaldy) 241, prepupal H. haemorrhoidalis 351, and adult P. calceolariae 1075. the validity of the technique and the relevance of the results to practical field application are discussed in terms of a phytotoxicity threshold of 150 μg oil/cm2. Copyright © 1995, Wiley Blackwell. All rights reserved