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COMPARATIVE OPTIMAL TIMES OF APPLICATION OF BENZOYLPHENYL UREAS TO WESTERN SPRUCE BUDWORM, CHORISTONEURA OCCIDENTALIS FREEMAN (LEPIDOPTERA: TORTRICIDAE)
Published online by Cambridge University Press: 31 May 2012
Abstract
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.
Résumé
On a testé quatre urée-benzoylphényles (BPU) contre les quatre stades larvaires défoliateurs de la tordeuse occidentale de l’épinette, Choristoneura occidentalis Freeman, provenant d’une colonie non diapausante. Les BPU testés étaient le chlorfluazuron, le penfluron, le triflumuron, et le XRD-473 (N-(((3,5-dichloro-4(1,1,2,2-tetrafluoroéthoxy)phényl-amino)carbonyl)-2,6-difluorobenzymide). Des résultats antérieurs indiquaient que les BPU étaient généralement plus actifs contre les jeunes chenilles, mais les larves du dernier stade se sont avérées les plus sensibles parmi les quatre stades. Des tracés de contour de l’efficacité estimée durant le développement d’une population expérimentale de laboratoire de la tordeuse ont montré que le moment optimal de traitement (LC90 la plus faible) pour le XRD-473 était environ 16 jours après l’éclosion du premier lot de larves, mais que le moment optimal serait plutôt entre 40 et 50 jours après le début de l’éclosion pour les autres composés. Cependant, l’âge chronologique des insectes dans une population naturelle étant difficile à estimer dû aux fluctuations des facteurs climatiques et notamment la température, on discute du besoin d’estimer le moment optimal d’application en fonction de l’âge physiologique de la population en développement.
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- Copyright © Entomological Society of Canada 1989
References
Hudes, E.S., and Shoemaker, C.A.. 1988. Inferential method for modeling insect phenology and its application to the spruce budworm (Lepidoptera: Tortricidae). Environ. Ent. 17: 97–108.Google Scholar
Gillette, N.L., Robertson, J.L., and Lyon, R.L.. 1978. Bioassays of TH6038 and difluron applied to western spruce budworm and Douglas-fir tussock moth. J. econ. Ent. 71: 319–322Google Scholar
Granett, J., and Retnakaran, A., 1977. Stadial susceptiblility of eastern spruce budworm (Choristoneura fumiferana) (Lepidoptera: Tortricidae) to the insect growth regulator Dimilin. Can. Ent. 109: 893–894.CrossRefGoogle Scholar
Retnakaran, A., and Wright, J.E.. 1987. Control of insect pests with benzoylphenyl ureas. pp. 205–282in Wright, J.E., and Retnakaran, A. (Eds.), Chitin and Benzoylphenyl Ureas. Dr. W. Junk, Dordrecht, The Netherlands.CrossRefGoogle Scholar
Robertson, J.L. 1979. Rearing the western spruce budworm. USDA Misc. Publ. Canada/United States Spruce Budworms program. 18 pp.Google Scholar
Robertson, J.L., and Haverty, M.I.. 1982. Estimation of rates and times of application for selected insect growth regulator formulations to western spruce budworm. J. Georgia ent. Soc. 17: 297–307.Google Scholar
Robertson, J.L., Lyon, R.L., Andrews, T.L., Moellman, E.E., and Page, M.. 1979. Moellman spray chamber: versatile research tool for laboratory bioassays. USDA For. Serv. Res. Note PSW–335.Google Scholar
Robertson, J.L., and Preisler, H.K.. 1986. XRD-473 (an experimental benzoylphenylurea): rates and optimal time of application to western spruce budworm. J. ent. Sci. 21: 16–20.Google Scholar
Robertson, J.L., Richmond, C.E., and Preisler, H.K.. 1985. Lethal and sublethal effects of avermectin B1 on the western spruce budworm (Lepidoptera: Tortricidae). J. econ. Ent. 78: 1129–1132.Google Scholar
Robertson, J.L., Smith, K.C., Savin, N.E., and Lavigne, R.J.. 1984. Effects of dose selection and sample size on the precision of lethal dose estimates in dose-mortality regression. J. econ. Ent. 77: 833–837.CrossRefGoogle Scholar
Russell, R.M., Robertson, J.L., and Savin, N.E.. 1977. POLO: a new computer program for probit analysis. Bull. ent. Soc. Am. 23: 209–213.Google Scholar
Summers, C.G. 1988. Cultivar and temperature influence on development, survival, and fecundity of four successive generations of Acyrthosiphon kondoi (Homoptera: Aphididae). J. econ. Ent. 81: 515–521.Google Scholar