Sex ratio of the coprophagous beetle community (Coleoptera: Scarabaeidae: Scarabaeinae) in the Andean Amazon, Caquetá, Colombia.

Abstract

Objective: Our study aimed to test whether the populations of dung beetle maintain the Fisherian sexes ratio a primary forest of an Andean-Amazonian ecosystems. Scope. Promote knowledge of the diversity of Scarabaeidae: Scarabaeinae from Caquetá, Colombia. Methodology: Coprophagous beetles were collected using 50 Pitfall traps baited with human feces separated from each other by 10 meters. Each trap was active for 72 continuous hours. Species were classified according to the trophic guilds and three size categories. Sampling effort was explored using an accumulation curve, meanwhile, Hill numbers were calculated to measure diversity. the Fisher test was performed to analyze the sexual ratio. A Chi-Square (X2) goodness test was performed to analyze if there were significant differences between trophic guild, species, sex and sizes. Results: In total, 693 individuals were collected, distributed in 12 genera and 26 species. The most abundant species were Eurysternus cayennensis Castelnau, 1840 and Dichotomius ( ichotomius) quinquelobatus (Felsche, 1910). The dominant trophic guilds were Diggers. The accumulation curve showed that the sampling effort were satisfactory, meanwhile, the Hill index showed that the abundances between species are heterogeneous. Fisher’s test showed a sexual ratio of 1.4:1 male-female. The X2 test showed that there were significant differences between the trophic guild, species, sex and sizes. This study is the first approximation of the sexual ratio of dung beetles in the Colombian Andean-Amazonian region. Conclusions: This study provides relevant information on the sex ratio and habits occurrence for 12 genera and 26 species of Scarabaeidae that occur in the Parque Nacional Natural Alto Fragua Indi Wasi, San José del Fragua, Caquetá, Colombia.