Ants (Hymenoptera: Formicidae) diversity in agricultural ecosystems at Mezquital Valley, Hidalgo, Mexico

We studied the changes in ant communities within agricultural ecosystems according with their seasonal variation and type of irrigation (well water and wastewater) in five plots. Plots were located in the Mezquital Valley, in the central Mexico. Collects were carried out in 2003, from February to March (dry season) and August (rainy season) using Pitfall traps. A total of 1638 organisms were collected (477 and 1161, dry and rainy season, respectively), corresponding to 16 genera, Pheidole (42.38%) and Monomorium (26.67%) were the most frequently collected. The capture frequency of ants was 0.58 throughout the whole study (0.45 and 0.71, dry and rainy season, respectively). An ANOVA two-ways analysis shows a significant season, plot and interaction effect on the ant capture frequency. A high diversity was observed during the rainy season (14 species). The plots with low disturbances show more species richness and abundance, indicating that the quality of the water is a determining factor for the community structure. The genera Tapinoma and Odontomachus could be indicators of low disturbance levels.