External egg morphology of the Hawaiian dancing moth, Dryadaula terpsichorella (Lepidoptera: Tineidae)

Abstract

The Hawaiian dancing moth, Dryadaula terpsichorella (Busck 1910) (Lepidoptera: Tineidae), has been recently introduced into the continental USA, in California and Florida. While the larva and pupa of a few species in the tineid subfamily Dryadaulinae have been described, the morphology of the egg has not been reported for any species in the subfamily. In this study, we report the egg morphology of D. terpsichorella. The egg is scale-like, which is unusual for Tineidae, and the chorion has reticulate sculpturing and numerous micropunctures over its surface. Five to eight obovate primary cells surround the micropylar area. The chorion of D. terpsichorella is similar to other tineid species in its reticulate pattern, but the shape of the egg is distinctively different. We postulate that the flattened shape may be related to the reduction of the ovipositor. While observations from other species are needed, we predict that the flat and singly deposited egg of D. terpsichorella may be shared with congeners in the subfamily. The flattened shape of the egg may be for attaching to the surface of plants effectively or preventing desiccation and predation.

Keywords:

• Tineidae
• Dryadaulinae
• Dryadaula terpsichorella
• upright egg
• scale-like egg
• reduced ovipositor

Acknowledgements

We thank Lou Somma and Paul Skelley (FDACS-DPI) for help with acquiring scanning electron microscope images. Patti Anderson and Marc Frank (FDACS-DPI), Sandy Koi (UF Entomology/Nematology), Andrei Sourakov (FLMNH), and two anonymous reviewers provided ideas and comments. In particular, Donald R. Davis (Smithsonian Institution) provided valuable comments on the variation in tineid egg morphology.