Observations on the sapro-xylophagous beetles (Insecta: Coleoptera) in Sotuta, Yucatan, Mexico

From August 2003 to July 2004, beetles were collected from secondary forest aged eight to 15 years with remnants of semideciduous forest in the "X'kitam" Ranch, in Sotuta, Yucatan, at 21 m elevation. Forty-seven trunks and stumps were examined randomly. From 4.2 m super(3) of wood of the 24 trunks examined, 69 larvae, three pupae and 65 adults were collected, representing 137 specimensbelonging to the families Cerambycidae, Curculionidae, Tenebrionidae, Melolonthidae, Passalidae, Carabidae, and Elateridae. The families with the highest abundance were Passalidae (36.49%), Tenebrionidae (21.16%), and Cerambycidae (23.35%). Seventy-one percent of the families belong to the decomposer guild. As decomposition advances the number of families was observed to diversify considerably in stages II and HI, and then decreased in stage IV. Eighty-eight percent of the xylophagous beetles preferred the sapwood and heartwood habitat, and 12% the subcorticular habitat The presence or absence of larvae, pupae and adults was not related to the volume of each trunk (r = 0.10981, df = 20, P < 0.01), but rather to the degree of decomposition of the trunk and resource availability. The sapro-xylophagous guild of Sotuta is more similar to that of Acahuizotla, Guerrero (191 specimens in 6.5 m super(3)), given that the number of specimens collected in both communities represents less than 10% in comparison with the equivalent from Soconusco.