Taxonomy | Geometridae | Geometrinae | Hemithea

More trouble.

The genus Hemithea is not straightforward.

In Hong Kong there are three species known and at least one other possible.
Known:
H. tritonaria
H. insularia
H. marina
Suspected:
H. krakonaria

problem is that on external morphology only H. marina is identifiable in the field. The other three belong to the H. neptunaria group.

H. marina
note the terminal fascia is only slightly darker green than the ground colour, not black as per the neptunaria complex, in which tritonaria is described from Hong Kong, the other key species being neptunaria, posidonaria, insularia and krakenaria - see Moths of Borneo 9).
Species in the neptunaria group are best determined by dissection as the genital morphology is distinct. Larval morphology may also be diagnostic, though as yet only H. insularia & tritonaria have been reared in Hong Kong.

Other similar genera.....

Jodis, Maxates and Chlorissa.

Jodis & Maxates species have no abdominal blotch
Chlorissa aquamarina has no terminal fascia and a paler, jade green, more translucent apprearance.

Here's a visual comparison:

H. tritonaria OR H. insularia (black wing margin)	H. marina (dark green / concolorous wing margins)
Jodis nanda (no abdominal blotch, no terminal fascia)	Maxates microdonta group (no abdominal blotch, dark green / concolorous wing margins)	Chlorissa aquamarina (no terminal fascia, pale jade, strong discal dots)

Posted on November 15, 2023 03:48 PM by hkmoths