caa a22 4500 38636091X CHVBK 20180307111914.0 cr unu---uuuuu 161130e198901 xx s 000 0 eng 10.4039/Ent12175-1 doi S0008347X00028510 pii (NATIONALLICENCE)cambridge-10.4039/Ent12175-1 COMPARATIVE OPTIMAL TIMES OF APPLICATION OF BENZOYLPHENYL UREAS TO WESTERN SPRUCE BUDWORM, CHORISTONEURA OCCIDENTALIS FREEMAN (LEPIDOPTERA: TORTRICIDAE) [Elektronische Daten] Four benzoylphenyl ureas (BPU'S) were tested on the four feeding larval instars of western spruce budworm, Choristoneura occidentalis Freeman, from a nondiapausing laboratory colony. BPU's compared were chlorfluazuron, penfluron, triflumuron, and XRD-473 (N-(((3,5-dichloro-4-(1,1,2,2-tetrafluoroethoxy)phenyl-amino)carbonyl)-2, 6-difluorobenzymide). Although previous evidence suggested that BPU'S were generally most active on younger instars, last-instar western spruce budworm larvae were most susceptible to three of the four tested. Contour plots of estimated effectiveness during development of a western spruce budworm laboratory population indicated that the optimal time of application (lowest LC90) for XRD-473 would be ca. 16 days after the first group of larvae hatched, but the optimal time for the other three BPU's would be between 40 and 50 days after hatch began. However, chronological age of insects in natural populations is difficult to estimate because of the influence of factors such as climatic conditions (e.g. temperature) and other ecological factors. The need to estimate optimal timing for application of BPU's and other chemicals in terms of physiological time during population development is discussed. Copyright © Entomological Society of Canada 1989 Robertson Jacqueline L. Pacific Southwest Forest and Range Experiment Station, Forest Service, U.S. Department of Agriculture, Berkeley, California, USA 94701-0245 Worner Susan P. Entomology Department, Lincoln College, Canterbury, New Zealand Preisler Haiganoush K. Pacific Southwest Forest and Range Experiment Station, Forest Service, U.S. Department of Agriculture, Berkeley, California, USA 94701-0245 The Canadian Entomologist Cambridge University Press 121/1(1989-01), 75-79 0008-347X 121:1<75 1989 121 TCE https://doi.org/10.4039/Ent12175-1 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.4039/Ent12175-1 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Robertson Jacqueline L. Pacific Southwest Forest and Range Experiment Station, Forest Service, U.S. Department of Agriculture, Berkeley, California, USA 94701-0245 NATIONALLICENCE 700 1- Worner Susan P. Entomology Department, Lincoln College, Canterbury, New Zealand NATIONALLICENCE 700 1- Preisler Haiganoush K. Pacific Southwest Forest and Range Experiment Station, Forest Service, U.S. Department of Agriculture, Berkeley, California, USA 94701-0245 NATIONALLICENCE 773 0- The Canadian Entomologist Cambridge University Press 121/1(1989-01), 75-79 0008-347X 121:1<75 1989 121 TCE CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge