FNZ 49 - Lithinini (Insecta: Lepidoptera: Geometridae: Ennominae) - Popular summary
Weintraub, JD; Scoble, MJ 2004. Lithinini (Insecta: Lepidoptera: Geometridae: Ennominae). Fauna of New Zealand 49, 48 pages.
( ISSN 0111-5383 (print), ; no. 49. ISBN 0-478-09357-8 (print), ). Published 29 Apr 2004
Lithinini looper moths
The Lithinini are one of the most widespread tribes of ennomine looper moths, with representatives on every continent except Antarctica. These small, narrow-bodied moths are one of the few groups of herbivorous insects that exploit ferns as their primary food source.
This tribe is represented in New Zealand and its offshore islands by 3 endemic genera comprising 8 endemic species. These moths favour forest habitats although species associated with bracken fern ( Pteridium esculentum ) may sometimes occur in more disturbed areas along forest margins or in scrub. The adult moths visit flowers of various plants (e.g., native Myrtaceae including "White Rata" [Metrosideros perforata (J.R. & G. Forst.) A. Rich.]; cultivated Loganiaceae [Buddleja davidii Franchet]) to feed on nectar. The females deposit eggs on or near the ferns on which the larvae feed. Larvae feed singly on the vegetative portion of ferns, and crawl off the growing portion of the plant to pupate in leaf litter, just below the surface of the soil, or among dead fronds of the host.
These moths utilise a broad range of ferns as host plants. Recorded hosts include many different growth forms from low-growing members of the forest herb layer such as Paesia (Dennstaediaceae) to broadleaved ferns such as Microsorum (Polypodiaceae) and the towering tree ferns Cyathea (Cyatheaceae) and Dicksonia (Dicksoniaceae).
The larvae of Lithinini exhibit a characteristic defense mechanism when disturbed, dropping or actively jumping off the host plant and twisting/turning rapidly if the disturbance continues. Adults are attracted to lights, and like many other forest Geometridae, may also be collected by beating or sweeping vegetation in suitable habitats. The normal flight period begins at dusk and continues until the ambient temperature is too low for adults to fly. Most New Zealand Lithinini are bivoltine, and usually overwinter in the pupal stage.
New Zealand's lithinine moth fauna is endemic and surprisingly diverse for a relatively small country (the entire Palaearctic region at comparable latitudes has only 2 species in 2 genera). These moths are well adapted to life in temperate rainforest with high pteridophyte diversity and biomass, and New Zealand's forests represent one of the best examples of such an optimal lithinine environment.