Pupal metamorphosis of the moth Cyana coccinea (Moore 1878) (Lepidoptera: Erebidae)
2019
Hawes, Timothy C.
The pupae of Cyana coccinea are described in relation to the principal developmental stages of metamorphosis (ecdysis, pupa, pharate pupa and eclosion). Species identification of the pupae can be made by the presence of striation patterns on the wing buds (lateral view). Striations show individual variability but conform to a recognisable template. Both fresh exuviae and exuviae kept for over three years could be readily identified on the basis of retained markings. Males and females show slight sexual dimorphism and can also be discriminated by colour and wing pattern in the pharate stage. The ejection of the larval skin out of the cage-cocoon that is characteristic of the genus is achieved by a telescopic extension of the abdomen as it pushes the skin out of the cage with peristaltic contractions. Extension is 60% of the body length of the contracted pupae. After the removal of the larval exuviae, the lower abdominal segments undergo a series of smaller movements to enable the hooks of the cremaster to find purchase on the guy lines of the suspensory silk hammock. Eclosion is preceded by a glistening of the cuticle that indicates a release of cocoonase a few hours before emergence.
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