Neoponera verenae

A common species that is found in a variety of habitats. Neoponera verenae nests in rotten wood and logs in twigs and under stones. (Mackay and Mackay 2010, Traniello and Hölldobler 1984, Wild 2002)

Identification
From Mackay and Mackay (2010): The lack of erect hairs on the dorsum of the mesosoma, petiole and first tergum of the worker and the female of N. verenae would separate this species from all of the others of the genus Neoponera , except for Neoponera apicalis, Neoponera obscuricornis, Neoponera bucki and Neoponera magnifica. Neoponera verenae can be separated from the last two species by the large eyes, which occupy more than 1/3 of the side of the head. The workers and females of N. verenae can be separated from N. apicalis as the apex of the funiculus is usually dark, but may be reddish brown, but is never yellow as it is in N. apicalis. The posterior lateral edges of the petiole of the worker and female of N. verenae are sharp and may even form a carina, whereas in N. apicalis this area is mostly rounded.

This species has been consistently confused with N. obscuricornis. Wild (2005) recently resolved the confusion between the species. The two species can be easily separated as the posterior lateral margins of the petiole of N. verenae are sharp, those of N. obscuricornis are broadly rounded. Additionally N. verenae lacks the dense pubescence on the hypopygium, which is present on the hypopygidium of N. obscuricornis. Neoponera verenae is much more common than N. obscuricornis.

The male of N. obscuricornis is completely dark brown or black, including the entire antenna, which would separate it from that of N. apicalis, in which the antenna is completely pale brown. The side of the petiole lacks the rugae that are found in the male of N. apicalis. Thus it is unlikely that the male would be confused with the other two closely related species. It may be difficult to separate it from the unknown male of the rarely collected Neoponera cooki from Colombia south to Brazil.

Distribution
Mexico through central South America.

Distribution based on Regional Taxon Lists
Neotropical Region: Bolivia, Brazil, Costa Rica, Ecuador, Guatemala, Honduras, Mexico, Nicaragua, Panama, Paraguay.

Habitat
Neoponera verenae is a common species that is found in tropical rain forests, subtropical forests, riparian habitats, riparian areas in the llanos [grasslands], gallery forests and wet forests to open urban environments and cacao plantations, from 0 to 925 m elevation. Wild (2005) notes that southern populations seem to be more commonly collected in open habitats while northern populations are more likely be found in forests. (Mackay and Mackay 2010)

Biology
Wild (2005):

Almost all the information published about N. verenae appears in the literature under the name Neoponera obscuricornis (see this species page for more about previous species determination problems). This common species exhibits great flexibility in habitat. 14 specimen records are from rainforest or other types of wet forest, seven are from forest edge habitats, five from open natural habitats such as campo cerrado or savannah, one from pasture, one from tropical scrub forest, and one from a cacao plantation. Interestingly, southern populations seem to be more commonly collected in open habitats, while northern populations are more likely to be found in forest. This species displays similar nesting habits to Neoponera apicalis and Neoponera obscuricornis. Three nest records from specimen collection data were from rotting wood, and one from a grass clump in a pasture. Traniello and Hölldobler’s (1984) study colony was collected nesting in a log in Panama, and Wild (2003) reports a nest in rotting wood in Paraguay.

Neoponera verenae is a predaceous and scavenging species. Foragers will also carry droplets of liquid held between their mandibles, a common trait in poneromorph ants (Hölldobler 1986). Longino (2004) has observed N. verenae attacking live lepidopteran larvae in Costa Rica, and captive colonies have taken crickets, cockroaches, termites, and other insect parts (Traniello & Hölldobler 1984, Oliveira & Hölldobler 1991, Gobin et al 2003). Foragers use visual cues (Duelli & Duelli-Klein 1976), and there is no recruitment to food sources (Traniello & Hölldobler 1984). Colonies are small, reportedly with fewer than 100 workers. Gobin et al (2003) collected 27 colonies from La Selva in Costa Rica with a median number of 39 workers per colony. The study colony of Fresneau (1984) contained 57 workers, and that of Traniello and Hölldobler (1984) grew to about 80–90 workers. N. verenae appears to be polygynous. Traniello and Hölldobler’s study colony had “several” fertile queens, and Fresneau (1984) found developed ovaries in five of seven dealate queens. Oliveira & Hölldobler (1991) described the agonistic interactions between workers and unmated queens in a queenless laboratory colony. These dominance interactions have a measurable energetic cost to the colony (Gobin et al 2003).

Neoponera verenae has been the subject of considerable research on gland structure. Abdominal glands in the male were described by Hölldobler and Engel-Siegel (1982), the pygidial gland by Traniello and Hölldobler (1984), the metapleural gland was briefly investigated by Hölldobler and Engel-Siegel (1985), and the ultrastructure of the labial gland was reported by Lommelen et al (2002, 2003).

Tandem-running, a stereotyped behavior where an ant recruits a single nestmate at a time, was investigated in Neoponera verenae by Traniello and Hölldobler (1984). N. verenae was found to employ tandem-running during nest relocation, mediated by a pheromone originating in the pygidial gland of the lead ant and spread to the hind-legs by a self-grooming behavior.

There is one record in of N. verenae in the gut contents of Bufo coniferus Cope in Nicaragua.

Nomenclature

 *  verenae. Neoponera apicalis var. verenae Forel, 1922: 90 (w.) PANAMA. Mackay & Mackay, 2010: 562 (q.m.). Combination in Neoponera: Schmidt & Shattuck, 2014: 151. Junior synonym of apicalis: Brown, 1957e: 230. Revived from synonymy and raised to species: Wild, 2005: 10. See also: Mackay & Mackay, 2010: 561.

Worker
From Mackay and Mackay (2010): The workers are moderate sized (total length 8 - 9 mm) black ants. The mandibles are mostly smooth and glossy; the remainder of the ant is dull, which forms a strong contrast. The malar carina is well developed and sharp. The eyes are large, occupying more than ⅓ of the length of the side of the head. The scapes extend about ⅓ length past the posterior lateral corner. The dorsum of the mesosoma is nearly straight, but is slightly depressed at the metanotal suture. The shoulder of the pronotum is swollen but does not form a distinct carina. The propodeal spiracle is elongated and slit-shaped. The petiole is thick when viewed in profile with both the anterior and posterior faces being convex and rounded and meeting at a rounded apex. The posterior lateral borders of the petiole meet at a sharp margin, which nearly forms a carina. The metasternal process is formed of two wide lobes, which are more separated near the apex than at the base. The lower inner margin has oblique striae.

Erect hairs are sparse, with a few on the mandibles, clypeus, coxae, femora, tibiae (many of the hairs on the legs are suberect), ventral surface of the gaster and posterior ⅓ of the gaster. Erect and suberect hairs are absent on the side of the head (a few may be present on the cheeks or on the malar area) the dorsum of the mesosoma, the petiole, the first and on most of the second terga.

The mandibles of the worker are finely striate and moderately shining. The remainder of the ant is either very finely striate or very finely punctate and dull.

Queen
From Mackay and Mackay (2010): The female (undescribed) is similar to the worker, lacking erect hairs on the dorsum of the mesosoma, the petiole and most of the dorsum of the gaster. The large eyes and the well-developed carina anterior to the eye would further assist in recognizing this species. The posterior lateral edges of the petiole form a sharp carina. The total length is 12 mm, the head length is 2.4 mm and the head width is 1.7 mm. The eyes are large (0.86 mm maximum diameter) located less than one diameter from the anterior edge of the head. The ocelli are small (the diameters of the medial and lateral ocelli are 0.09 mm). The scape (2.7 mm) extends about ⅓ length past the posterior lateral corner of the head. The carina on the side of the pronotum is sharp and slightly overhangs the side of the pronotum. The propodeal spiracle is slit-shaped and the stridulatory file is well developed. The sculpture is similar to that of the worker.

Male
From Mackay and Mackay (2010): The male (undescribed) is a moderately large (total length about 12 mm) black specimen. The cavity at the base of the mandible is relatively large with the depressed area being more than ½ the length of the mandible. The head length is 1.5 - 1.6 mm; the head width 1.3 - 1.4 mm. The eyes are relatively small with a diameter of 0.8 mm (side view). The ocelli (maximum diameters of the medial and lateral ocelli 0.2 mm) are separated by about one diameter. The pronotal shoulder is swollen but does not form a margin. The Mayrian sutures are developed but do not connect in the center of the scutum; the parapsidal sutures are well developed. The propodeal spiracle is slit-shaped. The petiole is rounded dorsally and the two faces (anterior and posterior) are about equal in length and shape. The posterior lateral regions of the petiole are broadly rounded and not sharply bent as they are in the worker and the female. The stridulatory file on the second pretergite is well developed and even slightly wider than it is in the worker and female.

Most of the bodily surfaces including the sides of the head, the dorsum of the mesosoma, the dorsum of the petiole and all surfaces of the gaster are covered with short (most about 0.25 mm in length) flexuous golden or silver hairs.

The tiny mandibles are weakly shining and the remainder of the body is dull.

It would be difficult to recognize the male without workers or females.

Type Material
Panamá. Lectotype worker, 1 paralectotype worker designated, (Mackay and Mackay 2010)

Etymology
This species was named in honor of an unspecified woman named Verena. (Mackay and Mackay 2010)