Potential geographical distribution of species of the genus Tachysphex (Hymenoptera: Crabronidae) in Mexico

Wasps of genus Tachysphex (Hymenoptera: Crabronidae) are cosmopolitan with 56 known species in Mexico. Using the MaxEnt tool and multivariate statistics, the potential geographic distribution of 48 of these species, plus 4 from the southern border of the USA, was characterized in relation to biogeographic provinces, conservation areas, human activity sites, and environmental variables. The genus was distributed in 89.4% of the territory and on average each species was found in 12.4% of Mexico. The California and Baja California provinces present the sites with the greatest richness and similarity. The four largest provinces of the northwest correspond to the Nearctic distribution and those of the rest of the Mexican territory mark the trend of Neotropical distribution. The 5.8% of the species occupied areas with high anthropic impact and 61.5% in untransformed areas. Winter precipitation and solar radiation in September were the variables most related to the potential distribution of wasps. The highest species richness occurred in areas with low humidity, consistent with the trend observed towards areas of low humidity in the USA. The high winter precipitation characterizes the dry continentalized Mediterranean climate that occurs in large areas of the Baja California Peninsula.