Effect of Structural Variation of Dead Trunks on Passalid (Coleoptera: Passalidae) Assemblages in Central Amazonian Campinaranas.

The present study investigated the occurrence of passalids in dead trunks with structural variations. Trunks were found in areas of white sand forests, locally known as Campinarana, in the state of Amazonas, Brazil. The collections were extended from May to December 2009. The mean diameter of the trunks and their stage of decomposition were classified, and the species of Passalidae were classified according to the location of their galleries. We used multiple generalized models to investigate the relationship between abundance and permutational multivariate analysis of variance (PERMANOVA) to investigate the relationships between predictors and passalid composition. A total of 361 passalids belonging to 13 species were collected from 11 tree species, of which Aldina heterophylla represented the highest proportion of logs (55%). Only the diameter of the trunk was related to the abundance of species, with trunks of larger diameters presented more individuals. The passalid composition was correlated with the diameter and decomposition of the trunks of all species of trees and only with the diameter of the trunks of A. heterophylla. Most of the species collected in Campinaranas construct their galleries in two or more regions of the trunk. The region that supported a greater number of colonies was the sapwood, followed by the inner bark and the soil-stem interface. The general habit of passalids found may be advantageous, probably to compensate for the low dispersion and isolation in areas with low availability of resources, such as Campinaranas forests in the Amazon.

Passalidae (Coleoptera: Scarabaeoidea) from the West-Most Brazilian Amazon Region: Checklist, New Records, and Identification Key.

We present a list of Passalidae species found in the westmost Brazilian Amazon region, which is considered to be a diversity-rich area due to being a tectonic and geographic transition zone in relation to Brazilian Amazon lowlands and the Andean range. The specimens acquired in field collections and museums were analyzed. Their geographical distributions were estimated based on data from labeled specimens and the literature. Twenty-nine species belonging to two subfamilies, six genera, and four subgenera were listed. Among them, 20, 1, and 2 showed to be new records for the region, Brazilian Amazon, and Brazil, respectively. An identification key is provided for the species being listed.

Passipassalus brevicornis n. sp.: a New Passalidae (Coleoptera) from Brazilian Amazonian, with a Key to the Species of Passipassalus Reyes-Castillo & Fonseca.

Passipassalus brevicornis n. sp. is described from two specimens from Tefé and Coari, Amazonas, Brazil. This species represents the fifth species recognized of Passipassalus and differs from the other species of the genus mainly by having an apex of central tubercle of median frontal structure not free, frontal fossae with some scarce setae, metasternal fossae with scarce setae, humeri fully pubescent, and marginal groove over anterior ventral edge of femur I marked and complete. Additionally, a key to the species of Passipassalus is given.