Description of the immature stages of the Neotropical whirligig beetle Gyrinus (Neogyrinus) rozei Ochs, 1953 (Coleoptera: Gyrinidae) and first report of the parasitoid wasp Melanosmicra sp. (Hymenoptera: Chalcididae) on a Gyrinus species.

In most species of Gyrinidae, the immature stages are unknown, especially due to the difficulty in collecting the juveniles and assigning them to a particular species. Molecular association is a feasible technique that may solve this problem. Recent studies have used DNA sequence data, specifically the gene cytochrome oxidase subunit I (COI), to associate immature and adult stages, thus enabling the description of the former.

Gyrinus rhyssonotum sp. n., a new species of Gyrinidae (Coleoptera: Adephaga) from northern Brazil.

Gyrinus rhyssonotum sp. n. is described and illustrated based on adult males and females collected in Barcelos County, Amazonas state, Brazil.

Gyretes Brullé (Coleoptera: Gyrinidae) from Brazil: Morphology of eggs and early instars.

Taxonomic information regarding Gyrinidae is mostly based on adults, especially due to the difficulty in collecting immatures and assigning them to a particular species. Association between immatures and adults is sometimes difficult because closely related species can be found in the same habitat. To solve this problem a feasible technique is rearing under laboratory conditions.

A Checklist of the Gyrinidae (Coleoptera: Adephaga) of Brazil.

A checklist of all known species of the water beetle family Gyrinidae (whirligig beetles) recorded from Brazil is assembled. This checklist is based on literature published prior to 2012. A total of 206 species and subspecies are cited for Brazil, distributed among three genera (Enhydrus Laporte, 1834, Gyrinus Geoffroy, 1762 and Gyretes Brullé, 1835).