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Determination of the Number of Instars of the Silkworm Anaphe venata Butler (Lepidoptera: Notodontidae)

  • M. O. Ashiru
Research Article

Abstract

The number of instars in the silkworm Anaphe venata was determined using three methods namely: (1) direct observation of cast exuviae by larvae reared through the entire larval stage, (2) use of frequency distributions of head capsule lengths and widths taken from larvae representative of the entire larval stage of the species and (3) morphological observations and examinations of larval segments and anal plates. Seven instars were observed for A. venata. The most reliable method was the direct observation of cast exuviae by larvae reared through the entire larval stage. It is further suggested that either the method of histograms of head capsules or examination of larval segments and anal plates be used to supplement this method for better reliability.

Key Words

Anaphe venata silkworm instar numbers 

Mots Cléfs

Anaphe venata ver à soie nombre d’instar 

Résumé

Le nombre d’instars dans le ver à soie Anaphe venata était déterminé en utilisant trois méthodes-notamment (1) L’observation directe de jet (exuvise) par les larves qui sont élévées entierement a travers l’étape larvaire. (2) L’emploi des distributions de fréquence de longeur et de largeur de capsule de tête pris des représentatives des larves dans toute l’étape larvaire des espèces et (3) les observations et inspections morphologiques des segments larvaires et des plaques anales.

Sept instars étaient observés pour A. venata. La methode le plus sûr était l’observation directe de jet exuvise par les larves élévées à travers l’étape larvaire toute entière.

Il est proposé que la méthod d’histogram de capsule de tête ni l’inspections morphologiques des segments larvaires et des plaques anal peut être utilisée pour complètes cette méthode-pour mieux solidité.

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Copyright information

© ICIPE 1988

Authors and Affiliations

  • M. O. Ashiru
    • 1
  1. 1.Forestry Research Institute of NigeriaEntomology SectionIbadanNigeria

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