1 School of Biological Sciences, Victoria University of Wellington. New Zealand
Pitfall traps are commonly used to sample active and surface-living invertebrates, though this technique could be not effective to study some target invertebrate species. The goal of this approach is to evaluate the efficacy of squid baits on sampling weta species as part of the PhD research: Top-down and bottom-up forces in forest invertebrate communities-implication for mammal control in New Zealand. Five pitfall sampling points were established on November 2012 and nine on February 2013 in Aorangi Forest. Four non-baited and three squid baited kill pitfall traps were set up around the center of each transect and were active one night during November and three night during February. Caught invertebrates were taken to the laboratory for later classification. The total number of weta caught in squid baited pitfall traps was 187 individuals, more than four times the number (46 individuals) caught in non-baited pitfall traps. The abundance of weta was particularly high in three-night active traps (February), 6.48 (±2.63) individuals on average, compared with 0.8 (±0.91) individuals on average in one-night active traps (November). Diptera and Araneae were almost always present in baited-traps. Our preliminary results show that squid-baited pitfall traps seem to be more effective than non-baited pitfall traps to catch weta species and one-night active traps is not enough to evaluate the weta diversity in Aorangi Forest.