POPULATION SIZE AND HABITAT OF Megasoma elephas Fabricius, 1775 (COLEOPTERA: DYNASTINAE) IN AN EJIDO OF CAMPECHE

Abstract

This work characterizes the habitat and biology of a population of Megasoma elephas at La Lucha Ejido, Calakmul, Campeche state. It regionalizes the information on the natural history of this beetle and proposes a viable utilization rate as a basis for future works. The size of the population was estimated using the Jolly-Seber method. For the habitat characterization, 400 m2 plots were established around the tree where Megasoma was caught; 500 m linear transects in the ejido area were also established, using the line interception method. 57 individuals were collected and 47 were marked; the proportion between the sexes was 1.62:1 (males: females). The estimated population size was 10 individuals, with a maximum of 595 and a minimum of zero. The estimated utilization rate was 25 specimens per year. For the habitat characterization, 229 trees, 18 families and 52 species were recorded; the 10 most abundant species represent 67.0% of the sampled specimens, and the most dominant species were Hampea trilobata, Bursera simaruba, Lasianthaea fruticosa var. fruticosa and Lonchocarpus xuul. Lonchocarpus guatemalensis, which occupies the eleventh place in abundance, was the species on which 100% of the M. elephas were observed. Compared to the data obtained in years previous to the study, significant differences were determined in population size but not in the body size of the individuals. The insects’ behavior in the region was observed, whereby new information was contributed to its natural history. The estimated utilization rate must be taken with reserve, since these results are based on a single stage of the life cycle and on a single specific period; therefore, it is suggested to make annual monitoring of adult populations, as wel as studying other stages of the species’ life cycle.