Dung beetles (Coleoptera: Scarabaeinae) diversity in an altitudinal gradient in the Cutucu Range, Morona Santiago, Ecuadorian Amazon

An assessment of the diversity of dung beetles (Coleoptera: Scarabaeinae) was carried out in the central part of the Cutucú Range, Ecuadorian Amazon. The composition and distribution of dung beetles in 10 sites, located from 500 to 2000 meters above sea level (masl), were determined through 11 samplings campaigns. Every sampling was done setting, during two days, 20 pitfall traps bated with human feces and 20 with decomposed fish, along a 950 meters transect. In total, 5655 beettles from 105 species were collected, the majority from: Deltochilum sp. barbipes GRP., Eurysternus caribaeus (Herbst), and Coprophanaeus telamon (Erichson). Ninety-six species were collected at the wet piedmont forest (500-1700 masl) and 27 at the humid low-mountain forest (2000 masl). Three new species were found: Cryptocanthon n. sp 1, Cryptocanthon n. sp. 2 and Uroxys n. sp. 7; but also 60 new records for the country. The more diverse sites were located between 700 and 1300 masl, but according to the relative abundance of beetles the study sites were grouped into three altitudinal levels: 600 - 700, 1100 - 1300 and 1700 - 2000 masl. Species richness showed similar patterns; except at 1700 and 2000 masl, which were separated into two groups. These results suggest that the high diversity of this sector is caused by its environmental variability through the altitudinal gradient; and confirm the importance of the Cutucú Range as a conservation area.