Insect Abundance in Grasslands and Woodlands at York University

The abundance of insects attracted to bright colours in different habitats was measured in the Saywell Woodlot and the Grassland east of Stong Pond at York University on September 30, 2014 between 2:30 PM and 5:30 PM. At this time, the temperature averaged 18ᵒC and the sky was dark due to a small amount of precipitation earlier in the day. A 100 foot transect was laid westward from the east edge of the Grassland and 3 sets of bowls were placed 5 meters apart along the transect, starting 10m west of the east edge. Each set of bowls consisted of 3 different coloured bowls (1 yellow, 1 blue, and 1 white) that were each half full with soapy water. Each bowl was directly adjacent to the other bowls of the set, forming a triangular formation. After placing the bowls in the Grassland, a 100 foot transect was laid northward from the north edge of the main path in the Woodlot. 3 sets of 3 bowls (1 yellow, 1 blue, and 1 white) half filled with soapy water were placed 5 meters apart along this transect, starting 10m north of the main path’s north edge. Each set of bowls was given 90 minutes before being examined for insects. Each set of bowls was treated as a single replicate, and counted for total abundance of insects, different RTUs, and abundance of Diptera, Hymenoptera, Orthoptera, and Hemiptera. Each independent insect was counted if it was submerged in the soapy water (dead or living) and had distinguishable features visible to the naked human eye. The experimenter determined the order of each individual insect through visual inspection and use of a dichotomous key.