August 2002. This is a contination of the Summary under Moth & Butterflies concerning Hippontion velox. It is the second moth which was responsible for the complete defoliation of Maninita Island, Tonga in May and June, 2002, after the island had completely recovered its foliage following Cyclone Waka on January 1st.
Maninita Island is dominated by Pisonia grandis and there was hardly a leaf left on the island thanks to the ‘Pisonia moth’ (Hippontion velox). The second most common tree is Neisosperma oppositifolia which was not affected, the third is Guettarda speciosa which was completely defoliated by this moth.
There was a difference of opinion on the identification of the moth. Was it Agrius convolvuli, the sweet potato hawkmoth as some thought or A cingulata Fabricius, 1775 (Sphingidae)? The latter is known to have a New World distribution, i.e., Canada to Argentina, Galapagos and Sandwich Is., as well as the Caribbean. The species is close to A convolvuli L., a well known pest distributed over the entire Old World.
Making matters even more complicated was the view of some members that the caterpillar illustrated here is Cephanodes armatus Rothschild and Jordan, a hummingbird hawkmoth with clear wings. It is known to feed on Guettarda and is known from Tonga. It was asked whether there could have been some confusion with the larvae collected on a creeper growing on Guettarda, such as morning glory (Ipomoea) or Convolvulus. However, it was said that the caterpillar was definitely feeding on the Guettarda; this was observed many times. Also, a hummingbird moth was observed on the island.
The baseline survey undertaken on Maninita Island can be downloaded at www.pacificbirds.com; go to Trip Reports Tab. In June, the rats were taken off the island (hopefully) and a follow up `baseline’ survey will be undertaken in a couple of years time, all being well.