Anochetus cryptus

AntWiki - Where Ant Biologists Share Their Knowledge
Jump to navigation Jump to search
Anochetus cryptus
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Ponerinae
Tribe: Ponerini
Genus: Anochetus
Species: A. cryptus
Binomial name
Anochetus cryptus
Bharti & Wachkoo, 2013

Anochetus cryptus antweb1008021 p 1 high.jpg

Anochetus cryptus antweb1008021 d 1 high.jpg

Holotype Specimen Label

This species seems to be rare in the Shivalik range of Northwest Himalaya and was collected from dry non-forested areas of the region. This is a hypogaeic species and was found mainly under large stones.

Identification

Bharti & Wachkoo (2013) - Anochetus cryptus, most resembles Anochetus evansi, but can be easily separated from it by dentate ventral margin of medial edge of mandible; strongly sculptured propodeum which in profile does not form a regular convexity with metanotum, whilst in the latter inner margin of medial edge of mandible is edentate; sculpture is feebler; metanotum forms a regular convexity with propodeum. Morphometrically, Anochetus evansi is relatively larger with HL 1.16; HW 1.03; EL: 0.12; ML: 0.59; SL: 0.89 and WL: 1.45. However, Anochetus schoedli also characterized by the absence of propodeal teeth or lobes and placed in the longifossatus group can be easily separated from Anochetus cryptus by striation of head extending barely past frontal carina, whereas in Anochetus schoedli striation reaches all the way to nuchal carina.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Oriental Region: India (type locality).

Distribution based on AntMaps

AntMapLegend.png

Distribution based on AntWeb specimens

Check data from AntWeb

Biology

Not much is known about the the biology of Anochetus cryptus 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.

Diet. 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

Nomenclature

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

  • cryptus. Anochetus cryptus Bharti & Wachkoo, 2013: 138, figs. 1-6 (w.q.) INDIA.

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

Description

Worker

HL: 0.91–1.12; HW: 0.80–0.97; EL: 0.06–0.07; MdL: 0.45–0.54; SL: 0.69–0.84; PnW: 0.42–0.51; MsL: 1.04–1.24; PtW: 0.24–0.26; PtL: 0.23–0.28; PtH: 0.30–0.34; TL: 3.70–4.65. Indices:CI: 87.91–93.27; SI: 84.68–86.60; MdI: 48.21–51.92 (n=12).

Head. Eyes with 3–4 ommatidia across greatest diameter, filling less than half the length of the orbital fossae. Scape slightly curved, barely reaching the posterior margin of occipital lobe. Mandible slender, broadened in distal half; medial edge with 2 nearly straight margins extending to semicircular preapical excision; ventral margin dentate; with head in “full-face” view and mandibles closed, denticles invisible dorsally; apical triad of teeth variable in shape from sharply pointed to blunt.

Mesosoma. Slender, with well-marked promesonotal and effaced mesometanotal suture; pronotum rounded above, anterior border of pronotal dorsum marginate; mesonotal disc convex, wider than long; propodeal dorsum triangular, depressed transversely behind metanotal spiracle, anteriorly narrow; in profile sloping behind into an oblique declivity. Propodeal angles divergent and bluntly rounded. Petiole. Petiolar node in lateral view, thin and tapered apically. In anterior view petiole with round summit; lateral margins nearly parallel and straight.

Gaster. Cylindrical; weakly constricted between first two segments; base of cintus of second gastral tergite with cross ribs.

Sculpture. Head punctulate, smooth and shiny except frontal striation; striae fine but distinct, fanning out posterolaterally, barely extending to middle of head dorsum, laterally entering antennal socket but not exceeding posterior and lateral margins of head; 2–4 rugae present anteriorly in antennal sockets. Pronotum mostly smooth and shiny; cervix distinctly transversely striate with irregular ruga; anterior border of pronotal dorsum with few fine striae arched in parallel to margin; pronotum laterally smooth and shiny and patchily rugose; promesonotal suture cross ribbed. Mesonotal disc shiny. Dorsum of propodeum and declivity rugo-striate and/or vermiculate. Mesopleuron and metapleuron smooth and shiny; ventral extremity of metapleuronwith fewoblique rugae. Gaster smooth and shiny, sparsely punctulate. Mandibles and antennae punctulate, punctures denser on latter. Two of the specimens collected from Chanaur are comparatively smaller, less shiny and more sculptured. Mesosoma is entirely opaque and rugo-vermiculate except shiny pronotum and katepisternum.

Vestiture. Pilosity short and moderate overall, sub-decumbent on head and suberect on remainder, obsolescent on lateral mesosoma. Appendages covered by dense appressed to decumbent pubescence.

Color. Living individuals yellow with orange tint. Dry specimens brownish yellow; gaster with brownish shading; epistoma and tip of mandible brown.

Queen

HL: 1.13; HW: 1.05; EL: 0.18; MdL: 0.54; SL: 0.85; PnW: 0.68; MsL: 1.36; PtW: 0.30; PtL: 0.33; PtH: 0.42; TL: 4.86. Indices: CI: 92.92; SI: 80.95; MdI: 47.78; (n=1).

As in worker, with modifications expected for this caste and the following differences: eyes with 10 ommatidia across greatest diameter; in front view dorsal margin of petiole concave. Propodeum obliquely striate; propodeal angles reduced; color darker than in corresponding workers.

Type Material

Etymology

The species epithet is Latin for cryptic, in reference to its cryptobiotic habitat.

References