caa a22 4500 38803551X CHVBK 20180307125003.0 cr unu---uuuuu 161130e199808 xx s 000 0 eng 10.1017/S000748530004222X doi S000748530004222X pii (NATIONALLICENCE)cambridge-10.1017/S000748530004222X Effect of early season insecticide use on predators and outbreaks of spider mites (Acari: Tetranychidae) in cotton [Elektronische Daten] The Australian cotton industry relies almost exclusively on synthetic insecticides for control of early season pests. These insecticides often disrupt predatory insect activity in the field. Potential predators of the twospotted spider mite, Tetranychus urticae Koch, in cotton, identified in field and confirmed in laboratory experiments, included a theridiid spider, a phytoseiid mite, a lacewing larva, predatory thrips, several Coccinellidae and several Hemiptera. These predators were mostly generalists, having previously been reported as predators of aphids or caterpillars of Helicoverpa spp. The effect of insecticides on T. urticae and its predators was evaluated in three field experiments. Cotton was artificially infested with T. urticae then sprayed five times at seven to ten day intervals with either dimethoate (140 g ai/ha), thiodicarb (750 g ai/ha and 187.5 g ai/ha), endosulfan (735 g ai/ha and 367.5 g ai/ha), methomyl (169 g ai/ha) or amitraz (400 g ai/ha). Tetranychus urticae populations reached higher densities in dimethoate, thiodicarb and methomyl treated cotton than in untreated cotton. Population densities of T. urticae in cotton treated with low rates of endosulfan or thiodicarb were similar to controls, while those in cotton treated with amitraz were lower. All insecticides caused significant reductions in at least one predator group. Significant negative relationships were found between early season abundance of predators and the mid-season abundance of T. urticae and positive relationships between predators and the lag-period for T. urticae outbreaks to develop. Predation is implicated as a key factor influencing the early season survival of T. urticae. The implications for developing integrated pest management strategies in cotton are discussed. Copyright © Cambridge University Press 1998 Wilson L.J. CSIRO Division of Plant Industry, Cotton Research Unit, Locked Bag 59, Narrabri, New South Wales, Australia, 2390 Bauer L.R. CSIRO Division of Plant Industry, Cotton Research Unit, Locked Bag 59, Narrabri, New South Wales, Australia, 2390 Lally D.A. CSIRO Division of Plant Industry, Cotton Research Unit, Locked Bag 59, Narrabri, New South Wales, Australia, 2390 Bulletin of Entomological Research Cambridge University Press 88/4(1998-08), 477-488 0007-4853 88:4<477 1998 88 BER https://doi.org/10.1017/S000748530004222X text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S000748530004222X text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Wilson L.J. CSIRO Division of Plant Industry, Cotton Research Unit, Locked Bag 59, Narrabri, New South Wales, Australia, 2390 NATIONALLICENCE 700 1- Bauer L.R. CSIRO Division of Plant Industry, Cotton Research Unit, Locked Bag 59, Narrabri, New South Wales, Australia, 2390 NATIONALLICENCE 700 1- Lally D.A. CSIRO Division of Plant Industry, Cotton Research Unit, Locked Bag 59, Narrabri, New South Wales, Australia, 2390 NATIONALLICENCE 773 0- Bulletin of Entomological Research Cambridge University Press 88/4(1998-08), 477-488 0007-4853 88:4<477 1998 88 BER CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge