Spatio temporal variations of two Oecanthus fultoni (Orthoptera: Gryllidae) populations in Central Mexico

We compared five population attributes of tree cricket Oecanthus fultoni Walker, 1962 (structure, density, abundance, sex ratio, and male density) in two localities of Central Mexico, with contrasting xerophytic scrub. The specimens were counted directly on plants and the adult males by aural detection. In Zapotitlan Salinas, Puebla the crickets were sampled in hours of the day, and in the Pedregal de San Angel, Mexico City they were sampled in hours of the night. The species was present in both sites throughout the year and it recorded five nymphal instars; but the population of Zapotitlan was multivoltine and that of Pedregal was univoltine. The mean crickets density was higher in the Pedregal (652.0 +/- 0.2 ind./ha) than in Zapotitlan 50.4 +/- 0.2 ind./ha); sex ratio was 1:1.2 (males: females) in Zapotitlan; while in Pedregal it was 6.1:1. We recorded a significantly lower density of males in Zapotitlan (83.41 +/- 5.3 ind./ha) than Pedregal (153.75 +/- 9.1 ind./ha); in both localities males density showed negative and significant correlation with the monthly precipitation values. Our results support the importance of seasonality on the tree cricket population responses.