Landcare Research - Manaaki Whenua

Landcare-Research -Manaaki Whenua

FNZ 54 - Hierodoris (Insecta: Lepidoptera: Gelechioidea: Oecophoridae) - Popular summary

Hoare, RJB 2005. Hierodoris (Insecta: Lepidoptera: Gelechoidea: Oeco­phoridae), and overview of Oecophoridae. Fauna of New Zealand 54, 100 pages.
( ISSN 0111-5383 (print), ; no. 54. ISBN 0-478-09378-0 (print) ). Published 24 Dec 2005

Oecophorid moths

Oecophoridae are an unusual family of small moths that occur throughout the world. Whilst most moth caterpillars feed on the living leaves of plants, the caterpillars of Oecophoridae usually feed on the dead leaves in the leaf-litter on the forest floor, or in dead wood. More than 4000 species of Oecophoridae are known worldwide, but most of these (over 3000) occur only in Australia, where many species have adapted to feed on the abundant resource of dead eucalyptus leaves. Adult oecophorid moths are often very dull in colour, their various shades of brown helping to conceal them from birds (and entomologists) as they rest amongst dead vegetation or on tree-trunks by day. However, even these brown species are often attractively speckled or patterned, whilst other species, especially those that mimic lichen, are extremely beautiful. It is difficult to tell oecophorids apart from other small moths, but most New Zealand species have rather broad wings, a wingspan of between 10 and 35 mm, and the labial palpi (mouthparts that lie either side of the tongue or proboscis) are curved up and back over the front of the head.

New Zealand has a diverse and interesting fauna of Oecophoridae, containing well over 200 species. This compares with only 86 species in the whole of the former U.S.S.R., an area about 80 times as great as New Zealand. Probably the abundance of leaf-litter and dead wood in New Zealand’s ancient evergreen forests over millions of years has aided in the evolution of such a large number of oecophorid species. Most New Zealand Oecophoridae have not been studied in detail since the 1920s, and only two new species have been scientifically described in the last 50 years. However, we know of many other unnamed species in collections, and 8 of these are described in this book.

The genus Hierodoris probably belongs to an ancient lineage, and only occurs in New Zealand. The 18 species are very varied in size and coloration, and some are very attractive, with metallic shining scales on their wings. Their caterpillars are also varied in their habits: some feed inside the twigs of trees or shrubs, for example tutu (Coriaria) or beech (Nothofagus); others on seedheads or leaf-tomentum of plants in the daisy family (Celmisia and Pachystegia); one has gregarious larvae that bunch together the twigs of conifers, manuka, kanuka, or tauhinu with silk, and feed on the dying leaves inside the spinning. There are several species whose life-history we do not know, and five species that are known from very few specimens, and may possibly be threatened.

One rare and particularly interesting species of Hierodoris, H. stella, imitates a bug. The antennae are thickened with scales and look like the bug’s antennae, and the wing-tips are bent downwards in the manner of the bug’s wings. The bug is thought to be distasteful to birds, so probably the moth has evolved its mimicry to avoid being eaten.