A new species of Colacus Ohaus, 1910 (Coleoptera: Scarabaeidae: Dynastinae) from the Mata Seca biotope of Brazil, and notes on Colacus morio Ohaus, 1910.

In this contribution, Colacus rubrofemoratus Sobral, Morais, Grossi new species (Coleoptera: Scarabaeidae: Dynastinae: Agaocephalini) is described and illustrated based on male specimens found in a transitional area of Caatinga, Atlantic Forest, and Cerrado in Brazil. In addition, the female of Colacus morio Ohaus, 1910 is redescribed, a distribution map for the genus is provided, and a new key to the species of Colacus is presented.

A tropical arthropod unravels local and global environmental dependence of seasonal temperature-size response.

In most ectotherms, adult body size decreases with warming, the so-called 'temperature-size rule' (TSR). However, the extent to which the strength of the TSR varies naturally within species is little known, and the significance of this phenomenon for tropical biota has been largely neglected. Here, we show that the adult body mass of the soil mite Rostrozetes ovulum declined as maximum temperature increased over seasons in a central Amazonian rainforest. Further, per cent decline per °C was fourfold higher in riparian than in upland forests, possibly reflecting differences in oxygen and/or resource supply. Adding our results to a global dataset revealed that, across terrestrial arthropods, the seasonal TSR is generally stronger in hotter environments. Our study suggests that size thermal dependence varies predictably with the environment both locally and globally.

Two new species of Aegopsis Burmeister, 1847 (Coleoptera: Scarabaeidae: Dynastinae) from the central Brazilian Cerrado.

Two new species of Aegopsis Burmeister, 1847 (Coleoptera: Scarabaeidae: Dynastinae: Agaocephalini), Aegopsis diceratops Sobral Grossi new species and Aegopsis vazdemelloi Sobral Grossi new species, are described and illustrated based on specimens collected in Cerrado habitat in the Brazilian states of Minas Gerais and Mato Grosso. The new species are similar to A. bolboceridus (Thomson, 1860). A redescription of A. bolboceridus is provided along with remarks comparing characters among these three species. A distribution map and a male and female key to the species in the genus are provided.