April 2011. The caterpillar of this moth from Cook Islands eats holes through the buds of Terminalia catappa, and keeps the remains threaded on its body as protection and camouflage. It also uses them as a cocoon.

The moth belongs to the family Gracillariidae. There are 35 hits for Gracillariidae + Terminalia in the BMNH’s Caterpillar Hostplants database, [http://www.nhm.ac.uk/jdsml/research-curation/research/projects/hostplants, mostly species from the genus Acrocercops, which have the general shape and pattern of the moth from Cook Is.

Later, and with more interrogation of http://www.gracillariidae.net using a search on Acrocercops + Terminalia + Australasian Region there are two hits – A. diffluella (http://www.gracillariidae.net/species/show/822) and A. ochroptila (http://www.gracillariidae.net/species/show/928) with only diffluella likely for the Cook Islands, as it’s known from New Guinea and the Solomon Is. No illustrations were available. It was suggested that contact was made with Willy de Prins (www.gracillariidae.net/species/contact) for a more specific confirmation