Kj. Collier et al., SUMMER LIGHT-TRAP CATCHES OF ADULT TRICHOPTERA IN HILL-COUNTRY CATCHMENTS OF CONTRASTING LAND-USE, WAIKATO, NEW-ZEALAND, New Zealand Journal of Marine and Freshwater Research, 31(5), 1997, pp. 623-634
The distribution of adult Trichoptera in light traps was investigated
alongside nine streams draining catchments under native forest, pine f
orest, or pasture near Hamilton, Waikato, New Zealand. The aim of the
study was to determine the relationship between abundance, taxonomic r
ichness, and community composition with respect to land use during sum
mer, and to evaluate the use of adult Trichoptera compared with benthi
c invertebrates as potential bio-indicators of the effectiveness of la
nd-management changes. Adult Trichoptera faunas alongside the native s
treams were dominated by Hydrobiosidae, Conoesucidae, and Helicopsychi
dae (each >10% of total Trichoptera numbers for at least two of the th
ree sites), whereas Leptoceridae, Oeconescidae, and Hydrobiosidae were
relatively abundant alongside at least two of the pine sites. Adult T
richoptera faunas at the pasture sites were strongly dominated by Hydr
optilidae which made up 47-85% of numbers caught at all sites. The mea
n number of individuals and taxa caught in light traps increased from
November to January and then declined in February for all land-use typ
es. Overall, total numbers and taxonomic richness of adult Trichoptera
were significantly lower at the pine sites compared to the pasture or
native sites. TWINSPAN classification of benthic invertebrates collec
ted in November clearly differentiated sites based on land use for pre
sence/absence and percentage abundance data. A similar pattern was evi
dent for most sites when adult Trichoptera faunas were used for the fo
ur sampling dates combined, suggesting that light trapping has potenti
al as a tool for bio-monitoring.