Brachyponera chinensis

The Asian needle ant is an East Asian native that is a common and abundant element of its native range. It was found introduced in the US close to 100 years ago (Smith 1934) but remained an obscure, unknown ant in the US after this initial discovery. Its presence was not noted again until McGown (2009) discovered and reported this ant in Mississippi. Pachycondyla chinensis is now known to occur and have locally abundant populations in Alabama, Georgia, North Carolina, South Carolina, Tennessee and Virginia, with viable colonies as far north as New York state and Rhode Island. This ant has a potent sting and appear to exert strong influences on native ant faunas in areas where it develops abundant populations. It is also becoming evident that the presence of the preferred prey of Pachycondyla chinensis, termites, positively influences their presence in the areas they are invading.

Identification
From Mackay and Mackay (2010): Brachyponera chinensis is an Old World species that was introduced into the New World. The combination of poorly developed mandibular teeth, the constriction at the metanotal suture and the form of the subpetiolar process, with a posteriorly directed lobe separate this species from all of the others present in the New World. Only the introduction of additional Old World species (at least in the New World) would make recognition of this species difficult.

Also see Brachyponera nakasujii for details about closely related species and the Caste section below for images that can help with determinations.

Distribution based on Regional Taxon Lists
Australasian Region: New Zealand. Indo-Australian Region: Philippines. Nearctic Region: United States. Oriental Region: Cambodia, Taiwan, Thailand, Vietnam. Palaearctic Region: China, Democratic Peoples Republic of Korea, Japan, Republic of Korea.



Japan (Honshu, Shikoku, Kyushu, Nansei Is, Ogasawara Is).

Habitat
From Mackay and Mackay (2010):Smith (1979) reports they occur in dark damp habitats in urban environments (Smith, 1934) and disturbed rural environments (Brown, 1958).

Biology
As this ant is found in more areas, and is becoming known as a destructive invasive pest, it is becoming an increasingly focused on species of interest. A climate change analysis (Bertelsmeier et al. 2013) predicts global warming will greatly increase the potential areas where Brachyponera chinensis can invade. Its northern spread in eastern North America will perhaps not be as dramatic as predicted by climate alone. Its preferred prey, termites, are lacking in most of the putative areas of possible range expansion.

Guenard and Dunn (2010): Examined ant diversity and abundance in mature forests of North Carolina. Where it was present, P. chinensis was more abundant than all native species combined. The diversity and abundance of native ants in general and many individual species were negatively associated with the presence and abundance of P. chinensis. A small subset of species larger than P. chinensis (Camponotus and Formica) was either as abundant or even more abundant in invaded than in uninvaded sites. The large geographic range of this ant species combined with its apparent impact on native species make it likely to have cascading consequences on eastern forests in years to come.

Mackay and Mackay (2010): Smith (1934), Koriba (1963) and Gotoh and Ito (2008) summarized the biology of this species. Small colonies were found in moist rotten wood or in the soil under stones, logs, debris, etc. (Smith, 1934). Sexuals were found in a nest in August in Norfolk, Virginia. Foragers were more active on cloudy days as compared with sunny days. They fed on dead insects, fish scraps and juices of decayed fruits lying on the ground. People at one unspecified locality claimed that they were occasionally stung. At the time of collection (spring, 1932) they were most common in the vicinity of the docks. They occurred over the entire town of Washington, North Carolina and to a lesser extent of Norfolk, Virginia. These ants are unusually common and successful in China and apparently feed on dead insects (Brown, 1958).

Rodriguez-cabal et al. (2012) in North Carolina, USA found B. chinensis was negatively correlated with the presence of Aphaenogaster rudis, decreased the seed removal rate of a myremchorous plant seed and was negatively correlated with a second forest plant that produces mymecochorous seeds: "The number of A. rudis workers was 96% lower in invaded than in intact plots, and the number of seeds removed was 70% lower in these plots. Finally, in invaded plots the abundance of Hexastylis arifolia, a locally abundant myrmecochorous plant, was 50% lower than in plots where P. chinensis was absent. A parsimonious interpretation of our results is that P. chinensis causes precipitous declines in the abundance of A. rudis within invaded communities, thereby disrupting the ant-plant seed dispersal mutualisms and reducing abundances of ant-dispersed plants.

Bednar and Silverman (2011) studied the association of this ant with termites in North Carolina: Pachycondyla chinensis nests in close proximity to and consumes subterranean termites (Rhinotermitidae). P. chinensis do not occur in habitats lacking Rhinotermitidae. We suggest that subterranean termites are critical for P. chinensis success in new habitats. We demonstrate that P. chinensis is a general termite feeder, retrieving Reticulitermes virginicus five times more often than other potential prey near P. chinensis colonies. Odors produced by R. virginicus workers, as well as other potential prey, attract P. chinensis. Furthermore, P. chinensis occupy R. virginicus nests in the lab and field and display behaviors that facilitate capture of R. virginicus workers and soldiers. Termites are an abundant, high quality, renewable food supply, in many ways similar to the hemipteran honeydew exploited by most other invasive ant species. We conclude that the behavior of P. chinensis in the presence of termites increases their competitive abilities in natural areas where they have been introduced.

Nomenclature

 * solitaria. Ponera solitaria Smith, F. 1874: 404 (w.) JAPAN. [Junior primary homonym of solitaria Smith, above.] Forel, 1900e: 267 (q.). Combination in Euponera (Brachyponera): Emery, 1901a: 47. Senior synonym of chinensis and hence the latter the first available replacement name: Brown, 1958h: 22.
 *  chinensis. Ponera nigrita subsp. chinensis Emery, 1895k: 460 (w.) CHINA. [Misspelled as sinensis by Imai & Kubota, 1972: 194.] Replacement name for solitaria Smith, F. 1874: 404. [Junior primary homonym of solitaria Smith, F. 1860b: 103.] [Note: chinensis junior synonym of solitaria Smith, F. 1874: 404 (synonymy by Brown, 1958h: 22); hence first available replacement name.] Wheeler, W.M. 1921c: 530 (q.); Ogata, 1987: 116 (m.); Wheeler, G.C. & Wheeler, J. 1986c: 88 (l.); Imai & Kubota, 1972: 194 (k.). Combination in Euponera (Brachyponera): Emery, 1909c: 367; in Brachyponera: Brown, 1958h: 22; in Pachycondyla: Brown, in Bolton, 1995b: 304; in Brachyponera: Schmidt & Shattuck, 2014: 80. Raised to species: Brown, 1958h: 22. See also: Mackay & Mackay, 2010: 247.

Ponera solitaria

Two worker syntypes in. Labelled “Japan. 74/16.” Acc. Reg.: “1874 no. 16. 2 Ponera solitaria. Hiogo (Japan). Presented by Fred. Smith. These insects were all collected by Mr Geo. Lewis, except those from Hokadadi which were collected by Mr Whiteley and Mr R. Fortune.” In the original description Smith gives the type-locality merely as “Hiogo.”

Worker
From Mackay and Mackay (2010): The worker is a small (total length 3.5 mm) brown specimen with yellowish brown mandibles, funiculi and legs. The mandibles have approximately 9 teeth, which alternate in size. The three apicalmost teeth are the largest with the first tooth approximately twice the length of the other two, which are approximately the same size. The transverse medial carina is poorly marked on the clypeus, the sides of the head are nearly parallel and the posterior margin is slightly concave. The head length is 0.88 mm; the head width is 0.75 mm. The eye is relatively large (maximum diameter 0.15 mm), located less than one diameter from the anterior margin of the head. The scape (0.85 mm) extends approximately two funicular segments past the posterior lateral corner of the head. The funicular segments are slightly swollen toward the apex, but do not form a club. The mesonotum is well defined on all sides and the mesosoma notably depressed at the metanotal suture. The propodeal spiracle is circular. The petiole is narrow when viewed in profile, with the anterior face being slightly concave near the apex and posterior face being slightly convex. Both faces narrow towards the apex and form a small horizontal dorsal surface. The subpetiolar process is a broad thick lobe, with a posteriorly directed sharp process. The metasternal process consists of two fang-like sharp elongate projections, similar to those found in members of the stigma species complex.

Erect hairs are sparse, but are present on the mandibles, clypeus, frontal lobes, a few hairs are present on the dorsum of the mesosoma, dorsum of the petiole and all surfaces of the gaster, a few hairs on the legs are erect. Very fine appressed sparse golden pubescence is found on most surfaces.

The mandibles are finely striated with scattered punctures the dorsum of the head is very finely and densely punctate and weakly shining, the dorsum of the mesosoma has similar sculpture. The sculpture on much of the side of the mesosoma, especially the side of the pronotum and mesopleuron and the lower part of the propodeum is smooth and glossy. The petiole has scattered punctures and is weakly shining; the gaster is sculptured and is slightly shinier.

Etymology
The name means that this species is from China. (Mackay and Mackay 2010)