Anochetus peracer

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

MCZ-ENT00034802 Anochetus peracer hal.jpg

MCZ-ENT00034802 Anochetus peracer lbs.jpg

A nest of this species was found in an epiphitic moss of a downed tree in rainforest. The types were collected (Wilson 1959, note under Anochetus variegatus) during early evening and were found foraging on the lower part of a tree trunk at the edge of rainforest.

Identification

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Indo-Australian Region: New Guinea (type locality).

Distribution based on specimens

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The above specimen data are provided by AntWeb. Please see Anochetus peracer for further details

Biology

Not much is known about the the biology of Anochetus peracer 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

Queens and males of this species are unknown.

Nomenclature

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

  • peracer. Anochetus peracer Brown, 1978c: 579, figs. 40, 53 (w.) NEW GUINEA.

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

Description

From Brown (1978):

Wilson (1959) assigned this specimen (holotype), along with another worker taken at the same time and place, to Anochetus variegatus, but noted differences in frontal sculpture and petiolar form between the Lae specimens and a paratype of A. variegatus in MCZ. The frontal striation in the A. variegatus types is strong, and extends well beyond the frontal carinae to fan out widely over the center of the vertex.

He says nothing about the differences in mandibular dentition that in my opinion are at least as important. The mesial edges of the mandibles in A. variegatus have the dorsal and ventral margins fused into one coarsely denticulate margin beyond midlength for nearly half the preapical length of the shaft; the most distal (preapical) denticle does not form an acute angle as in A. risii, A. peracer and related species.

A. variegatus, though similar to A. peracer in size and color, seems to me to represent a separate species that links the gladiator and risii groups, but is probably more comfortably placed in the former.

The second specimen of collection No. 711, mentioned by Wilson (1959: 509) and presumably belonging to A. peracer, is not now to be found in the MCZ collection, and I do not know where it is.

Worker

Worker, holotype: TL 5.8, HL 1.43, HW 1.29, ML 0.90, WL 1.83, scape L 1.26, eye L. 0.21 mm; CI 90, MI 63.

Similar to Anochetus risii in form, color and sculpture; yellowish-brown, with corners of head and appendages more yellowish, but the petiole gradually attenuated to a very sharp apical tooth, and the mandibles shorter (and broader in the apical half) and with ventral mesal margin of shafts only vaguely crenulate near the preapical angle, which is acute and directed mesad. Antennal scapes also shorter; surpassing posterior lobes of head by only about the length of the first funicular segment when the head is viewed perfectly full-face. Pronotum smooth and shining, except for the usual transverse-striation of the cervix; frontal striation confined to the area between the frontal carinae. Eyes relatively smaller than in A. risii.

Type Material

Holotype Museum of Comparative Zoology from Didiman Creek, Lae, New Guinea, 29 March 1955, taken in the early evening from lower trunk of a tree in lowland rain forest, E. O. Wilson, No. 711.

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 579, figs. 40, 53 worker described)
  • Wilson, E. O. 1959. Studies on the ant fauna of Melanesia V. The tribe Odontomachini. Bulletin of the Museum of Comparative Zoology. 120:483-510.