@article {191, title = {Amazonopsis cerdani (Coleoptera: Elmidae: Elminae), a New Species of Riffle Beetle from French Guiana with Habitat Observations}, journal = {The Coleopterists Bulletin}, volume = {75}, year = {2021}, pages = {427{\textendash}439}, abstract = {

A third species of Amazonopsis Barr, 2018, Amazonopsis cerdani Barr and Cerdan, new species (Coleoptera: Elmidae), is herein described from French Guiana. One female paratype of Amazonopsis theranyi Barr from Peru is tentatively reassigned to A. cerdani as a non-paratype. Photographic images of the male and female habitus, and the male genitalia, are provided, as is a distribution map and a key to the species.\ Amazonopsis cerdani differs from A. theranyi from Peru and Amazonopsis camachoi Barr from Venezuela by the presence of prominent spines on protarsomeres 1\–4 of males, among other characters. The habitat of this species is small, shallow, lowland streams with sandy-silty substrates and low flow. Specimens were collected from unconsolidated leaf litter in depositional areas, and from stick and leaf packs lodged in the current. Genetic analysis conducted on three specimens from two localities, a male and two females, showed that they are conspecific.

}, keywords = {aquatic beetles, DNA analysis, sexual dimorphism, South America, Streams, taxonomy}, doi = {10.1649/0010-065X-75.2.427}, author = {C.B. Barr and A. Cerdan and S. Clavier and J. Murienne} } @article {185, title = {A New, Sexually Dimorphic Species of Cylloepus Erichson from Brazil (Coleoptera: Elmidae)}, journal = {The Coleopterists Bulletin}, volume = {75}, year = {2021}, pages = {270{\textendash}274}, abstract = {

Cylloepus dimorphus Shepard, Sites, and Rodrigues, new species (Elmidae) is described from Brazil with a sexually dimorphic abdominal ventrite 5. Males have a protruding lobe on each side of the apex of ventrite 5. Females lack the lobes and are not distinguishable from congeners.

}, keywords = {Byrrhoidea, Neotropical, riffle beetle, taxonomy}, doi = {10.1649/0010-065X-75.1.270}, author = {W.D. Shepard and R.W. Sites and H.D.D. Rodrigues} } @article {186, title = {Revision of Macrelmis Motschulsky, 1860 in the Southwestern United States and Northern Mexico with Description of Four New Species (Coleoptera: Elmidae: Elminae)}, journal = {The Coleopterists Bulletin}, volume = {75}, year = {2021}, pages = {93{\textendash}120}, abstract = {

Four new species of Macrelmis Motschulsky, 1860 are described from the southwestern United States and northern Mexico: Macrelmis harleyi Barr, new species from Arizona, Macrelmis mexicana Barr, new species from Mexico, Macrelmis shepardi Barr, new species from Arizona, New Mexico, Texas, and Mexico, and Macrelmis texangusta Barr, new species from Texas and Mexico. Photographic images illustrate the external morphology and male genitalia of the new species, as well as that of Macrelmis shoemakei (Brown, 1971), Macrelmis moesta (Horn, 1870), and Macrelmis texana (Schaeffer, 1911), which occur in the same geographic region. The genitalia of M. moesta and M. texana are described and illustrated for the first time. A key to the 14 known species of Macrelmis occurring in the southwestern United States and Mexico is provided, accompanied by line illustrations of the genitalia of the remaining seven Mexican species not included in the species treatments. Also included are geographic distribution maps for the seven species that are discussed in this article.

}, keywords = {calcium bicarbonate-rich water, Harley P. Brown, Nearctic, riffle beetles, tufa}, doi = {10.1649/0010-065X-75.1.93}, author = {C.B. Barr} }