The Effect of Urban Forest Quality and Composition on Populations of Long-horned Beetles (Coleoptera: Cerambycidae)

We are evaluating the abundance and species richness of beetles in the family Cerambycidae in twelve forest fragments of northern Delaware.  These urban and suburban forests are part of the long-term FRAME program, which is comprised of 30 sites in the Mid-Atlantic region of the eastern United States. All sites, including those used for this study, have been characterized  in regards to soil, understory vegetation species and density, litter dwelling arthropods, and occurrence of amphibians, reptiles, birds, and mammals.

The cerambycid family is of particular interest because it contains a number of native and nonnative forest pests.  Many of these can be brought to baited traps.  In each forest fragment, we had four cross panel traps baited with three different attractant combinations and a control.  Our treatments were MelangeC which is a synthesized cerambycid aggregation pheromone, ethylene, a combination of MelangeC and ethylene, and isopropanyl which is used as the control.  Beginning in the last week of April, we collected all insects found in our traps once a week, and refreshed treatments in accordance with protocols developed by Hanks and Millar.  We collected for 22 weeks, and captured over 7,000 cerambycid beetles of over 50 species.  We are currently analyzing our data to see how factors such as weather, stand size, and surrounding land use impact species abundance and diversity between fragments.  Some of these analyses are being performed with the R "unmarked" package to examine which factors influence differences in occurrence and abundance among various species.