Abstract:
Beetles are among the most ecologically diverse group. The carabids (Coleoptera: Carabidae)
beetles are distributed in distinct habitats with the highest species diversity in habitats with high
vegetation and litter cover. The family Carabidae of ground beetles are common predators of many
different insects and other arthropods, including fly eggs, caterpillars, and others. They are
taxonomically and functionally very important component of terrestrial ecosystems. The ground
beetles are sensitive to environmental conditions and hence form well-defined richness gradients.
The ground beetles have been widely used as indicator species of arthropod diversity, altered land
use, environmental change, and land management practices. They also act as bioindicators that can
generate interest in environmental pollution research. Beetles can be easily sampled by various
methods, and there are several methods available for sampling in a variety of habitats and which
can vary in efficiency and effectiveness. Pitfall trapping has been commonly used for capturing
invertebrates that are active on the ground, as it works on a principle that, an invertebrate moving
on the ground simply falls into an open container dug into the ground. The aim of this study was
to establish the beetle abundance in different habitats at the University of Embu. Simple random
sampling using pitfall traps of 5 cm and 7.5 cm in diameter at two sites over three weeks was
carried out. Trap catches were analysed by site and by size of pitfall traps using ANOVA in Rstatistics.
Results showed no effect of trap size and that different sites were not statistically
significant. Over time, there was a fluctuation in trap catches in the two sites sampled. These results
indicate that populations of beetles may be influenced by other factors besides disturbance of
landscapes.
