Anochetus pupulatus

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Anochetus pupulatus
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Ponerinae
Tribe: Ponerini
Genus: Anochetus
Species: A. pupulatus
Binomial name
Anochetus pupulatus
Brown, 1978

Anochetus pupulatus casent0217512 p 1 high.jpg

Anochetus pupulatus casent0217512 d 1 high.jpg

Specimen Labels

The holotype was dug from dry soil at the base of a large tree in disturbed, open, dry-season deciduous woodland. Paratypes were collected from an evergreen forest.

Photo Gallery

  • Anochetus pupulatus queen, from Kerala, India. Photo by Kalesh Sadasivan.

Identification

Brown (1978) - Anochetus pupulatus is the smallest of the minute-eyed Anochetus species. Anochetus myops (Malaya), Anochetus longifossatus (Ceylon) and Anochetus subcoecus (Taiwan) are all larger in body size, the first 2 of these considerably so. In addition, myops has a bluntly rounded petiolar node.

A. longifossatus from Ceylon is similar, but larger and has a longer and straighter dorsal truncal profile, especially in the metanoto-propodeal area; this last is feebly concave in the front half, and gently convex in the posterior half, just before the propodeal teeth (which are small, but acute and erect in the specimen I have from Kandy, 600-700 m, E. O. Wilson). A. pupulatus, by contrast, has the front half of the metanoto-propodeum distinctly convex, and it becomes weakly concave only in the posterior part. A. longifossatus also has the mandibles still more strongly thickened apicad, and longer, and the funicular segments II-IV are longer, collectively = or > I. The eyes are a bit larger in longifossatus (eye L 0.10 mm, with about 18-20 facets), and the petiolar node is thicker in side view, with convex front and rear slopes, especially the rear. In front view, the apical crest is nearly straight, and the sides are more strongly convex than in pupulatus. The mesonotum in longifossatus is minutely roughened in part, but still shining, as are also the sides of the metanotum, and the gastric pubescence is rather dense and decumbent; color ferruginous yellow, gaster brown.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Oriental Region: India (type locality).

Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Biology

Not much is known about the the biology of Anochetus pupulatus but we can presume that its biology is similar to other Anochetus species. The following account of Anochetus biology is modified from Brown (1968):

Habitat. The places where Anochetus live are varied. Where they penetrate into the temperate zone, most species excavate nests in the earth. Occasionally the nest is dug under a covering rock. In the tropics, many nests are also dug in the soil, but in moist forested areas, a common site is the soil beneath a rotting log or other large mass of rotting wood, with extensions of the nest into the log itself. Another frequent nesting site in tropical forest is in the humus and leaf litter at the base of large trees, particularly between buttress roots. Anochetus species of medium or small size often nest in small pieces of rotting wood or bark, or even small rotting twigs or seeds and nuts lying in or on the forest litter. Some species tend to choose more arboreal nest sites.

Foraging for living animal prey takes place on the soil surface, within the soil-humus-log mold matrix, or on the trunks, branches and foliage of trees and plants wherever these are available. Fragmentary evidence indicates that most epigaeically foraging tropical Anochetus tend to do their foraging at dusk, at night, or during dawn hours. I found Anochetus africanus walking on tree trunks only at night in the Ivory Coast. Some species, particularly those with red heads or other aposematic coloration, apparently forage in the open more during the day. No systematic comparative study has yet been made of foraging hours for different species.

The food of Anochetus consists principally of living arthropods caught and killed or incapacitated by the ants. The smaller and more delicate species Anochetus inermis has been observed by me in a laboratory nest. The colony came from a piece of rotten wood from the floor of a wet ravine near Bucay in western Ecuador. The colony was fed with small tenebrionid beetle larvae (Tribolium castaneum), comparable in size to the A. inermis workers, and the latter attacked the prey with their mandibles in the familiar snapping manner, but very cautiously and nervously, with stealthy approach, extremely rapid strike, and instant recoil-retreat. After several attacks of this kind, with intervening periods of waiting, during which the beetle larvae fled, rested, or writhed about in distress, an ant would finally attack with its mandibles and hold them closed on the prey for long enough to deliver a quick sting in the intersegmental membrane. After this, the prey appeared to be paralyzed, or at least subdued, and sooner or later was carried off by the ant to the nest, and eventually placed on an ant larva. Frequent delays and excursions before the prey are finally immobilized and brought to the ant larvae in the nest may well have the function of allowing time for protective allomones of the prey to dissipate. Many tenebrionid adults, including Tribofium, possess potent quinonoid defensive allomones, but the larva is not known to possess quinones in this genus.

Nuptial flight. Although males of different species of Anochetus are commonly taken at light, other species are not. Stewart and Jarmila Peck gave me Malaise trap samples taken in western Ecuador that contained males of several species, but Malaise traps capture both day- and night-flying insects.

Defense. When a nest of any of the larger Anochetus species is breached, some of the workers immediately hide beneath leaves or other objects, while other workers rush about with open jaws, which they snap at foreign objects, or even at leaves and twigs, with an audible tick. On human skin or clothing, a worker will snap her jaws and hold fast to the surface with them, at the same time quickly bringing her gaster around to sting. The sting is long and strong, and to me the effect is shocking and quickly painful.

Most of the smaller and medium-sized Anochetus species feign death when disturbed, crouching flat against the surface, or rolling themselves into a ball and remaining still, often for a minute or more. Only when held do they sting. Their stings can be felt in most cases, but the effect is usually trifling.

Castes

Male unknown.

Nomenclature

The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.

  • pupulatus. Anochetus pupulatus Brown, 1978c: 591, figs. 14, 21, 22 (w.) INDIA.

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

Description

Worker

Holotype, worker: TL 3.0, HL 0.77, HW 0.69, ML 0.36, WL 0.87, scape L. 0.54, eye L 0.06 mm; CI 90, MI 47.

TL 2.9-3.1, HL 0.74-0.81, HW 0.68-0.71, ML 0.34-0.39, WL 0.86-0.88, scape L 0.54-0.57, eye L 0.06-0.07 mm; CI 88-92, MI 45-49.

Color clear light yellow throughout.

The smallest member of the genus, with compound eyes greatly reduced (to about 12-14 facets), filling only about half the length of the orbital fossae. Convergent to A. siphneus of West Africa, but with the frontal striation better developed, fine, and reaching back to embrace the posteromedian impression, but not extending all the way to the nuchal carina. Dorsal surfaces of head behind eyes densely and coarsely punctate, punctures mixed with striation mesad, and surface here opaque, but the punctures becoming spaced out a little on the sides and pasterolateral corners of the head, where the interspaces are smooth and shining.

Antennal scapes fail to reach posterior corners of head seen full-face by less than the apical thickness of a scape; funicular segments II, III, IV short, not or scarcely longer than broad, together shorter than I (pedicel). Mandibles nearly twice as thick in apical third as at their insertions; apical triad of teeth short and conical; preapical excision and angle absent to rather weakly developed; ventral mesial margins subcrenulate as seen from dorsal oblique view. Maxillary palpi 4-merous.

Trunk compact, gently convex in outline, the promesonotal and mesometanotal sutures broad and impressed, so that really 3 separate convexities, pronotal, mesonotal, and fused metanoto-propodeal, exist, the anterior part of the last rising slightly above the others. Propodeal teeth in the form of prominent but bluntly rounded, laterally compressed tubercles. Cervix and anterior margin of pronotum finely, transversely rugulose; metanoto-propodeum with dorsum finely transversely rugulose; pronotal disc and sides of trunk predominantly smooth and shining, as are also the propodeal declivity, petiolar node and gaster.

Petiolar node thin in side view, tapered to a sharp apex; in front view, the sides are vertical and only weakly convex; apical edge truncate and concave in the middle, leaving a subacute point on each side. Gaster thick, the first segment (postpetiole) slightly larger than second, and without a distinct constriction between. Middle tibiae without apical spurs.

Short, fine erect hairs, mostly paired bilaterally, often difficult to distinguish from background pubescence: 1 pair on frontal lobes, 1 pair on middle vertex, 1 pair on posterior vertex, 1 pair on humeri, another pair on anteromedian pronotum, 1 pair on posterior pronotum, 2 pairs on mesonotum; numerous, but still sparse, hairs generally distributed on both upper and lower surfaces of all gastric segments. Pubescense fine, appressed or decumbent, fairly abundant and conspicuous on head, dense but very short and fine on mandibles and appendages (which are mostly smooth and shining, though finely punctulate), dilute on trunk dorsum and gaster. The paratypes sometimes have an extra pair of erect hairs on the frontal carina, or an extra pair on the upper vertex or on the pronotal disc; the hairs are extremely delicate, and probably are easily lost to rubbing.

Type Material

Holotype worker Museum of Comparative Zoology one of a series (M-228) dug from dry soil at the base of a large tree in disturbed, open, dry-season deciduous woodland near Punnapuzha, at the western base of the Western Ghats, east of Nilambur, Kerala State, India, 10 April 1969 (A. B. Soans and W. L. Brown).

Paratypes, 18 workers (MCZC, The Natural History Museum, Musee d'Histoire Naturelle Genève, and elsewhere), all from southern peninsular India: Kottiyoor, Wynaad Taluk, Kerala State (Soans and Brown), evergreen forest litter berlesate; Valara Falls, 46 km SW Munnar, 450+ m, Cardamon Hills, Kerala State, team of Besuchet, Löbl, and Mussard, No. 49; 39 km E Kodaikanal, 650 m, Palni Hills, Madras State, Besuchet-Löbl-Mussard, No. 20; plus type nest series.

References

  • Brown, W. L., Jr. 1978c. Contributions toward a reclassification of the Formicidae. Part VI. Ponerinae, tribe Ponerini, subtribe Odontomachiti. Section B. Genus Anochetus and bibliography. Stud. Entomol. 20: 549-638 (page 591, figs. 14, 21, 22 worker described)