Hydraenidae, Mulsant, 1844

Benetti, Cesar João, Alencar, Janderson Batista Rodrigues & Hamada, Neusa, 2024, TaXonomic Catalog of the Brazilian Fauna: Hydraenidae (Insecta: Coleoptera), diversity and distribution, Zoologia (e 23069) 41, pp. 1-17 : 8

Historical Hydraenidae data in Brazil

The first Hydraenidae species to be recorded from Brazil was Hydraena sahlbergi Orchymont, 1923 . However, this is not the oldest name for a Hydraenidae from Brazil: It is actually Ochthebius fossatus LeConte described in 1855 from USA, but recorded for the first time from Brazil in 1943 ( d’Orchymont 1943) as O. nitiduloides d’Orchymont , later synonymized with O. fossatus by Perkins (1980). The second oldest name from Brazil corresponds to O. attritus LeConte , described in 1878, but first recorded from Brazil in 1943 as O. schubarti d’Orchymont , later synonymized with O. attritus by Perkins (1980).

The peak of species description and records from Brazil was in 1980, when 12 species were first reported for the country ( Fig. 3 ). The year with the second higher number of species reported is 2011 (7 records); both papers were published by Dr. Philip D. Perkins. The accumulation curve of species per year shows a significant rise in rates of Hydraenidae records in Brazil from 1980 onwards ( Fig. 4 ). The curve has continued to rise with recent contributions ( Jäch and Delgado 2018, Benetti et al. 2020, 2021, 2022, Benetti and Hamada 2022).

Until now, 10 different authors have participated in the description of Brazilian hydraenids ( Table 3): six from Europe, two from the United States, and two from Brazil. Among all authors, Perkins has described the highest number of Hydraenidae species, 20 (all as first author), corresponding to 58% of the Brazilian Hydraenidae fauna. Dr. Juan. A. Delgado from Spain has described six Hydraenidae species from Brazil (all as co-author), followed by Dr. Francis Balfour-Browne (four species, all as first author). Until 2020, no Brazilian had participated in the description of any Hydraenidae species from Brazil, as either the first author or co-author. In this year, Brazilian and foreign authors described two Hydraena species ( Benetti et al. 2020). Among the 10 authors who have described Hydraenidae species from Brazil, only one is a woman, Dr. Neusa Hamada, from Instituto Nacional de PesQuisas da Amazônia, who has participated in the description of three species. Historically, few women have authored papers providing the description of insect species, spotlighting an extensive gender gap that needs to be addressed in future research endeavors.

All primary type species (holotypes and paratypes) of Hydraenidae from Brazil are deposited in scientific collections in Brazil, Europe, and United States ( Table 4). Eighteen primary types are deposited in Brazil (35%), 18 in European institutions (35%), and 15 in U.S. institutions (30%). The institution that houses the largest number of Hydraenidae type species from Brazil is MZSP (São Paulo, Brazil) (11 type species), followed by USNM (Washington, D.C.) with 10 and NHMW (Wien, Austria) with five. As already pointed out by different authors (e.g., Machado and Martins 2022), such a high number of primary types in foreign institutions could represent a taxonomic impediment for local researchers, primarily because accessing these specimens via travel or loans can often be very difficult.

Figures

Figure 3. Number of Hydraenidae species recorded from Brazil by year (1923–2022).

Figure 4. Accumulation curve of Hydraenidae species recorded from Brazil by year (1923–2022), based on the first record of each species to the country.