A practical emergence chamber for collecting Coleoptera from rotting wood

The rotting wood habitat is a difficult medium to sample for beetles. The most invasive method is direct dissection of the wood with removal of the (often immature) insects. While this may be the most expedient method of surveying rotting wood, the collector is biased toward species with large and easy-to-see adults and larvae, and against species with small adults and larvae (e.g., Scolytinae with mature larvae 2–10 mm long). Additionally, larvae are often difficult or impossible to identify to the species level using existing literature.

A more thorough approach is to allow emergence of adult specimens from the log. Emergence chambers were made using 18-gallon (ca. 68-L) Sterilite® plastic tubs that were modified by adding a removable bottom collection cup and ventilation to the top and side.

Ninety emergence chambers were filled three-fourths full with dead wood of various decay classes, placed in a shaded location, and serviced monthly for 24 months in Great Smoky Mountains National Park.

Here we illustrate details of chamber design and discuss time budget and collection efficiency of these contraptions. A total of 5692 adult Coleoptera representing 51 families, 226 genera, and 275+ species were collected. Selected results are presented to illustrate the effectiveness of the design. We also compare this design to other published and unpublished emergence chamber designs.