Published online by Cambridge University Press: 31 May 2012
Although many traps have been designed to study the responses of Lepidoptera to light sources of various intensities and qualities (Gui et al., 1942; Taylor and Deay, 1950; Glick and Hollingsworth, 1954; Merkl and Pfrimmer, 1955; Frost, 1957), few have been designed for studies of flight periodicity. The first one designed for the latter purpose was described by Seamans and Gray (1934). It consisted of seven individual collecting units built into one structure, each unit being operated for one hour of the night. Interval light traps subsequently designed by Hutchins (1940), Nagel and Granovsky (1947), and Coon (Frost, 1952) are of the Minnesota type (Frost, 1952), having a lamp bulb, hood, baffle and funnel. Beneath the funnel is a turntable, which brings a series of collecting jars under the spout of the funnel at regulated intervals. The Rothamstead trap (Williams, 1935, 1948) is also based on a bottle-changing mechanism.