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NUMBER OF INSTARS OF THE PITCH PINE TIP MOTH, RHYACIONIA RIGIDANA (LEPIDOPTERA: TORTRICIDAE, OLETHREUTINAE)

Published online by Cambridge University Press:  31 May 2012

Paul M. Gargiullo
Affiliation:
Department of Entomology, University of Georgia, Athens 30602
C. W. Berisford
Affiliation:
Department of Entomology, University of Georgia, Athens 30602

Abstract

Head capsule widths were measured on 962 larvae of Rhyacionia rigidana (Fernald). Five instars were detected using multimodal analysis, and normal distributions of head widths for each instar are given. Regression using an exponential growth model was used to generate mean head widths according to Dyar's rule. These widths did not differ significantly from observed widths.

Résumé

La largeur de la capsule céphalique a été mesurée pour 962 larves de Rhyacionia rigidana (Fernald). Cinq stades ont été déterminés d'après la technique de l'analyse des modes multiples, et des distributions normales des largeurs de la capsule sont fournies pour chaque stade. On a utilisé la régression basée sur un modèle de croissance exponentielle afin de générer les largeurs moyennes suivant la loi de Dyar. Ces largeurs de capsule ne sont pas significativement différentes de celles observées.

Type
Articles
Copyright
Copyright © Entomological Society of Canada 1982

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References

Berisford, C. W. 1974. Comparisons of adult emergence periods and generations of the pine tip moths, Rhyacionia frustrana and R. rigidana. Ann. ent. Soc. Am. 67(4): 666668.CrossRefGoogle Scholar
Dickerson, W. A. and Kearby, W. H.. 1972. The identification and distribution of the tip moths of the genus Rhyacionia (Lepidoptera: Olethreutidae) in Missouri. J. Kans. ent. Soc. 45(4): 542551.Google Scholar
Dyar, H. G. 1890. The number of molts of lepidopterous larvae. Psyche, Camb. 5: 420422.CrossRefGoogle Scholar
Forbes, W. T. M. 1953. Note on multimodal curves. Ann. ent. Soc. Am. 46: 221224.CrossRefGoogle Scholar
Gargiullo, P. M., Berisford, C. W., and Pienaar, L. V.. Two-stage cluster sampling for pine tip moths. Environ. Ent. (in press).Google Scholar
Miller, W. E. and Neiswander, R. B.. 1959. The pitch pine tip moth and its occurrence in Ohio. Ohio agric. Exp. Stn (Wooster, Ohio) Res. Bull. 840. 23 pp.Google Scholar
Powell, J. A. and Miller, W. E.. 1978. Nearctic pine tip moths of the genus Rhyacionia: biosystematic review. U.S. Dep. Agric. Handbk 514. 51 pp.Google Scholar
Schmidt, F. H., Campbell, R. K., and Trotter, S. J. Jr., 1977. Errors in determining instar numbers through head capsule measurements of a lepidopteran — a laboratory study and critique. Ann. ent. Soc. Am. 70(5): 750756.CrossRefGoogle Scholar