Brachymyrmex heeri

Nomenclature

Species: Brachymyrmex heeri Forel, 1874

Usage: valid

General description

Brachymyrmex heeri is a shiny yellow to brown small, soft-bodied, nondescript species approximately 1.2–2 mm in length. It lives in polygynous colonies, occupies shallow nests often located in disturbed habitats, and has successfully established populations outside its native range. The species is native to the Neotropics, but was originally described from Zurich, Switzerland (Forel, 1874;1876). They where they were found in abundance on greenhouse orchids in tropical botanical garden, but the population was gone (possibly replaced by Plagiolepis) by 1904 (Santschi, 1923). Brachymyrmex heeri is a widespread across Central America, South America and the Caribbean (Kempf, 1972). It was also recently reported from the Galapagos Islands, where they were found in association with introduced hemipteran Icerya purchasi Maskell, and in the agricultural zone of San Cristóbal (Herrera and Longino, 2008). It is not clear the extent to which B. heeri is native (versus introduced) to many of the Caribbean islands (Wetterer and Wetterer, 2004). Thus far there have been no confirmed reports of the species establishing in the United States, but it has been intercepted at a Texas port of entry (Christopher Wilson, pers. comm.). In addition to Forel’s original description from Switzerland, the species has been reported from Germany, France and the Ukraine (Rasplus et al., 2010).

External links

AntWeb | AntWiki | EOL | BOLD

Risk statement

Not considered a significant pest species.

Diagnostic description

Diagnosis of worker among Antkey 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 6 facets). Eye length approximately equal to or slightly greater 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 sparse pilosity, giving it a shiny appearance. Color yellow to brown.

The taxonomy of Brachymyrmex is in considerable need of revision before many of the current species names can confidently be applied to specimens. Brachymyrmex heeri can be distinguished from most other introduced members of the genus by the following combination of characters: (1) sparse 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, and (4) eye length equal to or greater than malar distance. More yellowish specimens of B. heeri can be separated from the brown species B. patagonicus, but greater taxonomic study is required in order to separate darker B. heeri specimens. Joe MacGown (2012) suggests that dark B. heeri can be separated from B. patagonicus by the former’s lack of ocelli, but the presence/absence of ocelli may be an unreliable character (Christopher Wilson, pers. comm.).

Look alikes

Brachymyrmex minutus, B. obscurior, ​B. patagonicus. Nylanderia species and Plagiolepis ​species can look similar.

Distribution

Native range. Neotropics: South America, Central America and Caribbean.

Introduced range. Galapagos. Possibly parts of Caribbean.

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