Anochetus kempfi

Anochetus kempfi is a cryptic nocturnal ant, widely distributed in Puerto Rico and the Virgin Islands. It is found in various habitats ranging from dry forest to rain forest.

Identification
See description below.

Distribution
Torres et al. (2000): In addition to the two records cited by Brown, we have material from the following Puerto Rican localities. Municipalities: Arecibo, Gucinica Forest (Gucinica), Loiza, Luquillo, Rio Piedras, San Lorenzo, Susua Forest (Yauco), Trujillo Alto. Small islands and keys: Cabeza de Perro, Cayo Ratones (near Fajardo), and Culebra. We have also collected this species in the British Virgin Islands, (Guana 1.) and the U. S. Virgin Islands (Inner Brass, near St. Thomas).

Distribution based on Regional Taxon Lists
Neotropical Region: Greater Antilles, Puerto Rico.

Habitat
Torres et al. (2000): Anochetus kempfi inhabits dry forest (Gucinica; Culebra; Cayo Lobos; Guana 1.; Inner Brass), rain forest (Bisley, EI Yunque), moist forest (Susua), sandy beach (Loiza), pasture land (San Lorenzo; Luquillo), and urban woodland (Trujillo Alto).

Biology
The following is summarized from Torres et al. (2000):

Nests are difficult to locate and can be found in soil, in decomposing wood, under coconut seeds (our observations), and beneath stones (Wheeler 1908).

Colonies may have from 2 to 4 queens (this is believed to be the first record of polygyny in Anochetus) and up to 100 workers. Reproductives can be produced at any time of the year with many more males produced and few new queens. Workers apparently cannot produce eggs.

Queens are ergatoid. They hold their gaster somewhat elevated above their mesosoma, do not receive any special attention from workers, and feed directly upon prey brought to the nest by workers. Flightlessness in the queens suggests new colonies are established by budding or fission.

Males eclose fully pigmented. Their reduced mandibles appear to render them incapable of removing their pupal cocoon. Workers have been observed feeding males, helping them eclose and cleaning males once they have been freed from their cocoon.

Workers forage alone. There does not appear to be any recruitment nor do they employ alarm pheromones. Like Odontomachus the mandibles can be used by a worker to to launch themselves through the air if they are threatened. Prey is captured in the mandibles and stung immediately, which results in paralysis of the prey. Trophallaxis has been observed but is uncommon.

Eggs are not allowed to lie on the floor of the nest chamber. Instead workers carry and hold eggs, in packets, at all times. Larvae feed from prey items. Pupating larvae need soil particles to form their cocoon.

Chemistry
From Jones et al (1999) - Head extracts of A. kempfi have been shown to contain 2,5-dimethyl-3-isoamylpyrazine and 3-methyl-4-phenylpyrrole. These compounds most likely are mandibular gland products and have a pheromonal role.

Nomenclature

 *  kempfi. Anochetus kempfi Brown, 1978c: 611, fig. 52 (w.) PUERTO RICO. Torres, Snelling & Jones, 2000: 509 (q.m.).

Worker
Worker, holotype: TL 8.4, HL 1.61, HW 1.31, ML 1.05, WL 2.49, scape L 1.70, eye L 0.33 mm; CI 81, MI 65.

Paratype workers: TL 7.4-8.1, HL 1.52-1.62, HW 1.25-1.31, ML 0.97-1.05, WL 2.30-2.54, Scape L 1.61-1.80, eye L 0.31-0.32 mm; CI 81-82, Ml 64-65 (based on 4 workers from Culebra I. and Cataño, Puerto Rico).

Belonging to the the Anochetus haytianus superspecies, and very similar to Anochetus longispinus, but differing from it and from A. haytianus in possessing well-developed, erect, acute propodeal teeth. The spines atop the petiolar node (L about 0.20 mm) are not quite as long and slender as those of longispinus, but are much longer than those of haytianus. The striation is also finer and more opaque (sericeous in some lights) than in longispinus or haytianus, especially on pronotum.

Ferruginous yellow in color; mandibles, appendages and petiole pale yellow.

Queen
Torres et al. (2000):

Ergatoid, as predicted by Brown (1978). Measurements (mm): head width 1.33-1.37; head length 1. 57-1.60; mandible length 1. 03-1. 07; scape length 1. 60-1.63; Weber's length 2.43-2.47; total length 6. 97-7.22. Ratios: cephalic index 85; mandibular index 66-67; scape index 102. N = 2.

Queens are slightly smaller than their workers and similar in color, varying from light to dark ferruginous yellow; appendages are paler except that tarsi are contrastingly brownish. Being ergatoid, the queens are similar to their workers in appearance; ocelli are not present; the only obvious difference is the presence of distinctly demarcated meso- and metanotal sutures across the mesosomal dorsum; one of the two queens examined has vestigial wings that are obviously non-functional; the gaster is more voluminous than that of workers, even in an unmated callow queen.

Male
Torres et al. (2000): Measurements (mm): Head width 1. 00-1.10; head length 0.80-0.83; Weber's length 1.8-2.0; total length 4. 8-5. 3; wing length 3. 9-4. 5. Cephalic index 125-133. N = 5 (including apparent largest and smallest individuals available). Mandibles vestigial, as usual in Anochetus, edentate. Eyes prominent, 1.4-1.6 x longer than wide in profile and 1.0-1.2 x longer than upper interocular distance; in frontal view, upper interocular distance 1.4-1.6 x lower interocular distance. Flagellar segments long, third antennal segment about 3 x as long as wide and about 3 x as long as first segment (scape). Vertex strongly convex; ocelli large and ocellocular distance distinctly less than diameter of anterior ocellus. Integument shiny between minute piligerous punctures.

Mesosoma shiny between obscure fine piligerous punctures; scutellum strongly convex; propodeum, in profile, sloping and mostly flat, posterior declivity weakly differentiated.

In profile,a nterior face of petiole node evenly sloping, summit broadly rounded into short posterior declivity; anteroventral process well developed, its apex obliquely acute.

Metasomal terga shiny, punctures slightly better defined than elsewhere on body. Subgenital plate almost twice as long as broad, sides subparallel or slightly convergent apicad, posterior margin shallowly concave to nearly transverse. Genitalia as illustrated (Figs. 5, 6).

Color yellowish brown to light brown; mandibles and legs yellowish; first two antennal segments yellow,3 -13 brown; variable areas of lower face, gena, side of mesosoma and apical margins of metasomal segments also yellowish.

Head and body with abundant short, suberect yellowish hairs and scattered conspicuously longer sub erect yellowish hairs; on metasoma longer hairs abundant on sterna and progressively more abundant on successive terga.

Type Material
Holotype and 5 paratype workers, 2 of them headless (MCZC, ), from Culebra Island, Puerto Rico (W. M. Wheeler). According to the collector (Wheeler, 1908: 125), the Culebra samples, which he assigned to A. testaceus, came from "several colonies nesting under stones in the shade of trees along the dry arroyos on the higher part of the island (Monte Resaca). The number of individuals in a colony varies from about thirty to one hundred". Probably more Culebra specimens exist in. An additional paratype worker, slightly darker than the (possibly faded) Culebra sample, comes from Cataño, near San Juan, Puerto Rico (S. Peck), "from epigaean carrion trap #10."

Additional References

 * Jones, T. H., R. C. Flournoy, J. A. Torres, R. R. Snelling, T. F. Spande, and H. M. Garraffo. 1999. 3-Methyl-4-phenylpyrrole from the Ants Anochetus kempfi and Anochetus mayri. Journal of Natural Products. 62:1343-1345. DOI:10.1021/np990245t


 * Wheeler, W. M. 1908. The ants of Porto Rico and the Virgin Islands. Bull. Am. Mus. Nat. Hist. 24:117-158.