DISCUSSION
Collection of data
Investigation of the vertical stratification of butterflies is important for studying butterfly diversity in tropical rainforest (Wolda 1983; DeVries 1988).
However, access to the canopy is a major problem and alternate methods to butterfly walk-and-count transects (Pollard & Yates 1993) need to be used. In this study, the problem of gaining access to the canopy was partially overcome by using trapping methods.
However, fruit traps only trap the guild of butterflies that are attracted to rotting fruit and so only a part of the butterfly fauna can be studied.
Also there is no information concerning the distances over which species are attracted to traps, or if different species are attracted differently to traps making it difficult to determine the sampling area of traps.
The advantage of using traps is that it reduces the problems of identification in the field because all individuals are captured and more easily identified.
Thus fruit-baited traps are currently the best technique to sample butterflies in the canopy.