Root-feeding Chrysomelidae (Coleoptera) from lowland forest, Madang, Papua New Guinea

Study Extent

The study area was situated in the Madang Province of Papua New Guinea. It has a humid tropical climate with average annual rainfall of 3558 mm, a moderate dry season from July to September, and mean air temperature 26.5 °C (McAlpine et al. 1983). Fieldwork was performed in an approximately 6-km2 mosaic of secondary and primary forest vegetation near Ohu Village (145°41' E,5°14' S, 200m asl). Sample included eighty mature trees, 2–12 per tree species, from 21 tree species were selected for the study.

Sampling

Sample included eighty mature trees, 2–12 per tree species, from 21 tree species were selected for the study. Vegetation within a 5-m radius around each target tree was cleared and a trap designed to collect insects emerging from the ground was placed within a 2-m radius of each target tree. The trap was a 1 × 1-m square, 15-cm-high wooden frame embedded5cmdeep in the soil and covered with strong black cloth on top. Single transparent plastic containers partly filled with 70% ethanol were inserted in two opposite sides of the frame. Insects emerging from the 1-m2 area of the soil within the trap were attracted by light to the containers where they were collected in ethanol. Traps were emptied at weekly intervals. All collected chrysomelids were mounted, sorted to morphospecies and identified as far as possible by Samuelson. Voucher specimens are deposited at the National Agriculture Research Institute in Port Moresby and Bishop Museum in Honolulu. The traps were run in three consecutive series: the S1 series comprised eight traps run for 6mo (1 May– 31 October 2002), the S2 series comprised 36 traps run for 11 months (21 November 2002 –21 October 2003), and the S3 series comprised 36 traps run for 6 months (22 December 2003–22 June 2004). A different tree was used for each trap and series and the trees from different species were intermingled within the study area to avoid pseudoreplication.

Method steps

1. Full details can be found- Pokon, Rapo, Vojtech Novotny, and G. A. Samuelson. "Host specialization and species richness of root-feeding chrysomelid larvae (Chrysomelidae, Coleoptera) in a New Guinea rain forest." Journal of Tropical Ecology 21.6 (2005): 595-604.

The study was conducted in a mosaic of primary and secondary lowland humid rainforest near Ohu Village, Madang province, Papua New Guinea, at an elevation average of 150– 200 m a.s.l. and an annual rainfall of 3558 mm with low seasonal variation. The diverse vegetation is classified as mixed evergreen hill forest.