Establishment of larval populations of the dragonfly Tramea loewii Kaup, 1866 (Odonata: Libellulidae) in lakes of northern New Zealand

The dragonfly Tramea loewii (Odonata: Libellulidae) was first seen in New Zealand in 2005, on the Aupouri Peninsula, Northland, and is likely to be self-introduced from Australia. To determine whether the species had become established on the Peninsula, an aquatic survey of 17 lakes was carried out in November 2008. Larvae were found in eight lakes, including six at the southern end of the Peninsula. Most colonised lakes were surrounded by pasture and had dense marginal beds of sedges and rushes where most larvae were collected. Six of an estimated 14 larval instars were found, the penultimate (F-1) and antepenultimate (F-2) instars being most common. The most abundant prey items in the guts of 17 late-instar larvae were Corixidae, chironomid larvae and damselfly larvae. The potential effect of T. loewii on resident lake faunas is discussed briefly.