Vol. 90, No. 1, February 1979
51
LARGE CAPACITY PITFALL TRAP1
Mark W. Houseweart2, Daniel T. Jennings3, James C. Rea4
ABSTRACT: Describes materials, procedures, advantages and disadvantages of using
large capacity pitfall traps to inventory ground-dwelling fauna in spruce-fir forests.
Numerous investigators have designed and used pitfall traps for collecting
ground-inhabiting arthropods (see Southwood, 1966 and Thiele, 1977 for a
general account; and Uetz and Unzicker, 1976 for a critical review). The
simplest design is a cup, jar, can or bottle sunk into the ground so that the
mouth is level with the soil surface. Walking insects and other arthropods
fall into the trap and are retained by a preservative or killing agent. More
elaborate designs include traps with funnels, roofs, barriers, aprons and time-
sort devices.
As part of a study on natural enemies of the eastern spruce budworm,
Cftorafcwewra fumiferana (Clem.), pitfall traps were used to inventory the
ground-dwelling fauna. Spruce budworms are susceptible to predation from
ground-inhabiting predators during the spring and summer larval-dispersal
periods, and when large larvae and pupae drop from host trees to the forest
floor. Because our study spanned the spring rainy season, a large capacity
pitfall trap, which would not overflow, was needed. This Note describes
the materials, procedures, advantages and disadvantages of using these large
capacity traps.
MATERIALS
The components needed for construction of the traps are readily available
from most scientific stockrooms or biological supply houses and from hard-
ware/lumber yards. Each trap (Fig. 1) consists of a 150 mm plastic funnel,
a 2-liter plastic bottle, and a 30 x 30 x 0.6 cm apron fashioned from tempered
'Received November 6, 1978. Cooperative Forestry Research Unit, Journal Article
Series No. 7.
2Assistant Research Professor, Cooperative Forestry Research Unit, School of Forest
Resources, University of Maine, Orono, Maine 04469
3Principal Research Entomologist