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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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