Sticky trapping of adult mayflies, stoneflies and caddisflies alongside three contrasting streams near Hamilton, New Zealand

Abstract

Sticky traps were used to catch adult mayflies (Ephemeroptera), stoneflies (Plecoptera) and caddisflies (Trichoptera) alongside three second order streams bordered by pines (Pinus radiata), willow (Salix sp.) or native forest (predominantly kanuka, Kunzea ericoides) near Hamilton, New Zealand. Five traps were attached to tree trunks at each of three heights (0.5 m, 1.5 m and 5.0 m from base), and were changed monthly between September 1993 and February 1994. During this period, species richness and numbers of mayflies, stoneflies and caddisflies were highest atthe willow site (31 species and 75% of total numbers), followed by the native site (17 species and 19% of numbers) and the pine site (14 species and 6% of numbers). Catches at the pine site were dominated by mayflies (78% of numbers), whereas mayflies and stoneflies were both relatively abundant atthe native site (49% and 33%, respectively), and mayflies and caddisflies atthe willow site (53% and 44%, respectively). Highest numbers at each site were recorded in December-January, but there did not appear to be a seasonal pattern in species richness. Trap height did not have a significant effect on numbers of mayflies or caddisflies caught at the willow site in December. Sticky traps represent a cheap and passive means of catching predominantly flying adults where numbers are high. Our trap design is likely to be most effective alongside larger streams where the area of streambed relative to trap area is greater.