In Costa Rica (Jack Longino)
This is a widespread species, common in other parts of the world in synanthropic habitats. In Costa Rica it is less common than the related B. heeri, a similarly synanthropic species. I know B. obscurior from two collections in Costa Rica, both coastal. One collection is from a beach site 25km North of Cahuita on the Atlantic coast, the other is from the town square of Sierpe, a small port town in a mangrove estuary on the Pacific coast.
Introduced Range. USA: Hawaii (Maui, Oahu, Hawaii), Florida, Georgia, Louisiana, Missouri, Washington (King Co.). Samoa. Solomon Is. (Makira). Netherlands.
Diagnosis among workers of introduced and commonly intercepted species. Antenna 9-segmented. Antennal club indistinct. Antennal scapes surpassing the posterior margin of head by more than 1/5th their length. Eyes of moderate size (greater than 5 facets). Eye length less than malar distance. Head with or without distinct ocelli. Antennal sockets and posterior clypeal margin separated by a distance less than the minimum width of antennal scape. Dorsum of mesosoma lacking a deep and broad concavity. Metanotal groove present. Pronotum and mesonotum with pairs of erect hairs. Propodeum and petiolar node both lacking a pair of short teeth. Propodeum lacking posteriorly projecting protrusion. Metapleuron with a distinct gland orifice. Waist 1-segmented (may be hidden by gaster). Petiolar node appearing flattened. Gaster armed with acidopore. Gaster (especially first segment) with dense pilosity, giving it a dull appearance. Color dull brown.
Brachymyrmex obscurior can be distinguished from most other introduced members of the genus by the following combination of characters: (1) dense pubescence on the first gastral tergite, (2) antennal scapes exceeding posterior margin of head by at least 1/5 their length, (3) erect hairs on the pronotum and mesonotum, (4) eye length distinctly less than malar length, and (5) dull brown in color. MacGown (2012) offers that the species, is most similar to B. patagonicus, but can be differentiated by the much denser pubescence, especially on the gaster. Males of B. obscurior are concolorous dark brown; whereas males of B. patagonicus are bicolored with the head and gaster dark brown and the rest of the body, including the appendages, being pale yellowish-brown. Additional characters cited by MacGown (2007) to separate the two include the smaller eye of B. obscurior which is shorter than the malar space, compared to the larger eye of B. patagonicus which is approximately equal to the malar length.
Molecular Biology and Genetics
Statistics of barcoding coverage: Brachymyrmex obscurior
Public Records: 0
Specimens with Barcodes: 3
Species With Barcodes: 1
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