Seasonality and density of emerging insects of a mixed lowland broadleaf-podocarp forest floor, Orongorongo Valley, New Zealand

Abstract

Emergence traps were used continuously for 2 years to determine the population density and seasonality of invertebrates in a mixed lowland broadleaf-podocarp forest near Wellington, New Zealand. A total of 53 920 individuals of 21 invertebrate orders was caught. Although more individuals were caught in the first year than in the second, this was not consistent amongst the different groups or species. Dipterans, staphylinid beetles, and solitary wasps were the most numerous insects caught. Diptera, Araneida, Opiliones, and Hymenoptera emerged from the forest floor in every month of the 2 year study. Many other invertebrate groups were active throughout the year but seasonal catches were significantly different with more recorded in summer than in other seasons. Numbers of several species were positively correlated with temperature. Likely effects of the extended invertebrate activity on the forest ecology are discussed.