Natural history and identification of litter‐feeding lepidoptera larvae (insecta) in beech forests, orongorongo valley, new zealand, with especial reference to the diet of mice (Mus musculus)

Abstract

New Zealand, in common with Australia and New Caledonia, has 12–19% of its Lepidoptera associated with litter. Elsewhere in the world, reported litter‐feeding is characteristic of less than 5% of the relevant lepidopteran fauna. Studies in the Orongorongo Valley, New Zealand, have shown a coincidence of high numbers of the introduced house mouse (Mus musculus L.), litter‐feeding Lepidoptera, and heavy beech‐seed production. Stomachs from trapped mice commonly contain caterpillar fragments, many of which belong to species feeding on litter. In Orongorongo Valley Nothofagus forest, litter‐dwelling larvae of over 20 moth species attain a body length greater than 10 mm, and hence are attractive to mice. Aspects of their biology are discussed in relation to their availability to mice. The genera most often encountered are Tingena, Gymnobathra (Oecophoridae), Dumbletonius (Hepialidae), Mallobathra, Grypotheca (Psychidae), and Rhapsa (Noctuidae). A key is given to Lepidoptera larvae known to live in litter, and which may be encountered in pitfall or emergence trap catches and in litter samples from the Orongorongo Valley study sites. Additional to these litter‐dwellers are 40+ Lepidoptera species with canopy‐dwelling larvae which drop to the litter to pupate; families abundantly represented are Geometridae and Noctuidae. © 1996 Taylor and Francis Group, LLC.