The Effects of Pitfall Trap Spacing on Ant Richness (Hymenoptera: Formicidae), Abundance, and Composition in Dinder National Park, Sudan

Abstract

Ants play an important role in Sudanese biodiversity and environmental impact assessments, Although baiting is easy and cheap to implement, several considerations, such as the spacing among bait, can affect the estimation of the abundance and richness of ants species. In this study, we evaluated the effects of bait spacing on abundance and the number of ant species. We also demonstrate which distance between baits showed the best relationship between costs and the number of ant species sampled. We sampled 30 transects of 100 m with bait spacing ranging (2.5; 3.3; 5; 6.7; 10 and 20 m), spread over 1 km² into three different type of ecosystems (Wooded grass land, Riverine ecosystem and Maya ecosystem), at DNP located in Sudan. The bait spacing did not affect the ant diversity estimative. Regardless bait spacing, the number of species collected every five baits was around 8, and the average abundance was approximately 50 individuals. However, the number of species per bait was higher in transects with a larger gap between baits. Transects with bait spans of 20 and 10 m captured 50% more species per bait than transects with baits 2.5 and 3.4 m apart. Our study suggest that the most efficient sampling design using only baits in the park would be, to place 450 baits every 10 m and 20 m.