Anochetus

Brown, WL Jr.,, 1978, Contributions toward a reclassification of the Formicidae. Part VI. Ponerinae, tribe Ponerini, subtribe Odontomachiti. Section B. Genus Anochetus and bibliography., Studia Entomologica 20, pp. 549-638 : 550-555

publication ID

6757

DOI

https://doi.org/10.5281/zenodo.6284041

persistent identifier

https://treatment.plazi.org/id/8A68A8BE-7BCA-9737-EAD8-99EB931CDC4A

treatment provided by

Donat

scientific name

Anochetus
status

 

Anochetus View in CoL View at ENA   HNS

> Anochetus Mayr, 1861   HNS , Die Europäischen Formiciden, Wien, p. 53-54. Type species: Anochetus ghilianii   HNS = Odontomachus ghilianii Spinola, 1853   HNS , monobasic.

Myrmecia Fabricius, 1805   HNS , Systema Piezatorum, p. 423.

> Odontomachus   HNS , Illiger, 1807, Mag. Insectenk., 6: 194.> Odontomachus   HNS , F. Smith, 1858: 79.

> Odontomachus   HNS , Brown, 1973: 178, 183.

> Stenomyrmex Mayr, 1862: 711-712   HNS . Type species: Stenomyrmex emarginatus   HNS = Myrmecia emarginata Fabricius   HNS , by designation of Emery, 1911: 110; also Wheeler, 1911: 173. New synonymy.

> Anochetus   HNS subgenus Stenomyrmex   HNS , Emery 1890: 63-65. - Emery, 1911: 110. - Wheeler, 1925: 8-10, key. - Kempf, 1964: 237-246, Brasil, key. Kempf, 1972, 20-22, catalog of species.

> Myrmapatetes Wheeler, 1929 b: 6   HNS . Type species Myrmapatetes filicornis Wheeler   HNS , by original designation, monobasic. Synonymized by Brown, 1953: 2. [13]

> Anochetus   HNS , reviews and catalogs, etc., mostly regional: Emery, 1894: 185- 188, New World, key. - Forel, 1900: 58-63, India, Burma, Ceylon, key. - Bingham, 1903: 38-45, India, Burma, Ceylon, key. - Emery, 1911: 107-111, world catalog of species. - Arnold, 1915: 103-108, southern Africa, key; 1926: 214-218, southern Africa, supplement. - Wheeler,

1922a: 96-99, Congo; 1922c: 790-792, Africa, catalog of species; 1922:

1012-1013, Malagasy catalog of species. - Wilson, 1959: 502-510, Melanesia, key. - Kempf, 1972: 20-22, New World tropics, catalog of species.

Worker: Similar to Odontomachus   HNS and with the characters of subtribe Odontomachiti (see Part VI, Section A, p. 72-74); size small (TL 2,9 mm in A. pupulatus   HNS ) to moderately large (TL nearly 12 mm in A. inca   HNS ). Color usually dull; brown, blackish, red, or yellow, sometimes bicolored.

Cranium basically as in Odontomachus   HNS , but often shorter; always without the complex relief of the vertex in that genus, so that antennal fossa, ocular ridge, extraocular furrow and temporal prominence are all lacking, or at least poorly developed; median furrow replaced by a shallow and fairly broad posteromedian impression, more or less well developed in most species; nuchal carina rounded and continuous, or forming an obtuse, round-pointed V across the posterodorsal margin of the vertex, not forming an acute V on the midline; apophyseal lines not present on occipital face (see fig. 4, p. 94 of Section A). Eyes varying from large and with many fine facets to dot-like, with as few as 5 indistinct facets, each eye situated in a shallow, elliptical orbital fossa in the usual position for the subtribe, most apparent when the eye is small (fig. 11).

Mandibles linear, but varying from long and slender, with slender teeth in a series along the inner margins, as in A. horridus   HNS (fig. 9), to rather stumpy, thickened apicad, and armed only with the apical triad of stout teeth, in some small forms (fig. 13) such as A. subcoecus   HNS . Intercalary tooth of apical triad reduced to a small tubercle on the inside of the ventral apical tooth in a few species, or even obsolete. Under mouthparts much as in Odontomachus   HNS ; maxillary palpi apparently always 4-merous, rather short in most species; labial palpi short, 3- or 4-merous.

Trunk with well-marked promesonotal and mesometanotal sutures; metanotal spiracles present in many species, indistinct or absent in the smallest ones. Propodeum rounded into declivity, or biangulate, or bidentate according to the species. Petiolar node varying in the extreme among species, ranging from conical, with an acutely tapered apical spine ( A. gladiator   HNS ) to merely conical ( A. risii   HNS ) to erect barrel-shaped ( A. sedilloti   HNS ), thick bidentate ( A. faurei   HNS ), thin squamiform (axially compressed, A. katonae   HNS ), and so on, in all gradations. The squamiform nodes may be narrowly rounded at the apex in side view, or sharply cultrate, and in front view may have convexly rounded apical margins, or be truncate, emarginate or sharply bidentate.

Gaster ranging from compact to slender; first segment (postpetiole) large, and usually separated from second by a distinct constriction, which, however, is not developed in some species (e.g., emarginatus   HNS , gladiator   HNS , altisquamis   HNS ).

Legs with simple tarsal claws; apical spurs of tibiae 1, 2, 2 or 1, 1, 2 or 1, 1, 1 or 1, 0, 1; at least one spur on the hind tibiae always pectinate.

Sculpture varying from almost completely striate or rugose with gastric dorsum densely reticulate and opaque, to almost completely smooth and shining. The fanwise striation of the frons is present, at least in abbreviated form, in all known species. Mandibles, antennae and legs usually smooth or finely and densely punctulate.

Pilosity varies widely; erect hairs simple, usually fine, abundant on body and appendages, to very sparse and limited; the small cryptobiotic forms often have reclinate pubescence developed at the expense of longer standing pilosity.

Ergatoid: Fairly common, and may possibly be the only functional queen in some groups (e.g., emarginatus   HNS ). Like the corresponding worker, but often with 1 or 3 ocelli present; compound eyes usually larger; scutellum usually differentiated as a small, transversely elliptical sclerite.

Queen: With wings, or dealate, and the usual other differences from the worker; size only slightly larger in most species. Petiolar node often more strongly axially compressed. Eyes usually much larger than in the worker. Anal lobe of hind wing present in larger species, lost in some of the smaller ones.

Male: Habitus typical of small to medium-sized male Ponerini   HNS . Anochetus   HNS males are usually distinguished by their habitus, by large to very large compound eyes, and especially by the form of the petiolar node, which is usually a low, muted version of that of the female castes of the particular species. Most male nodes are either subconical or triangular in side view, the triangular ones being biangular above, often with the upper border weakly emarginate in front view; extreme forms are squamiform and apically emarginate.

The most remarkable thing about Anochetus   HNS males is the extreme variation of their terminaba from one species to the next. This is in contrast to

Odontomachus   HNS , in which the known males have very similar terminal structures, at least as seen in the undissected state. In Anochetus   HNS , all of the basic ponerine structures are usually present: pygidium (tergum VIII), hypopygium (sternum IX), cerci (on membranous segment X, the proctiger), and the parts of the genital capsule proper: parameres (gonocoxites), volsellae (with digitus and cuspis), and aedeagus (penis valves). All of these parts may vary strikingly among species, even species that seem closely related judging form worker-queen traits.

Unfortunately, males found associated in the nest with the female castes are known only for a minority of the species. Additional kinds of males are known from collections at light or by Malaise trap, but it has not yet been possible to link any of these securely to worker-based species. As it stands, 3 described species are based on single male holotypes: pangens   HNS and consultons from Sri Lanka, and filicornis   HNS from Larat Island off West Irian. Probably some or all of these belong to species described under different names from the worker caste, so that synonymy will eventually result from the correct association of the sexes.

The most primitive terminalia known appear to be those of A. isolatus   HNS (figs. 60, 61) from New Guinea; this has the pygidium drawn out into a stout, downcurved spine, and the hypopygium is a broad linguiform piece; the parameres are simple, with narrowly rounded apices. These conditions are as in Odontomachus   HNS , which can be regarded as either the sister-genus of Anochetus   HNS , or a line descended from such primitive Anochetus   HNS as A. isolatus   HNS or A. gladiator   HNS . These same traits are also found in the presumptive ancestral Ponerini   HNS (of subtribe Ponenti ). The most primitive Anochetus   HNS species on worker-queen characters is A. gladiator   HNS , but the gladiator   HNS male remains unknown.

From the condition of A. isolatus   HNS , one finds transitions to forms in which each paramere is constricted apicad into a ventrally-directed digitiform process ( A graeffei   HNS , fig. 77; A. consultons   HNS ; A. sedilloti   HNS ) that becomes separated from the main body of the paramere by a more or less complete and flexible suture, or in which the body divides into two lobes in a complex way ( chirichinii   HNS , figs. 56-59). The linguiform hypopygium tends to be narrowed, probably convergently, into a median, narrow, rodlike piece in some species of both Old World and New World groups, or, unexpectedly, into slender, bilaterally arranged, twin rods ( madaraszi   HNS , figs. 64, 65), or a deeply cleft plate ( chirichinii   HNS , fig. 58). In some New World species, the parameres develop fancy lobes, sometimes with grotesquely sculptured extremites (figs. 72, 73), but it is not completely certain that these are Anochetus   HNS .

Volsellae and aedeagus vary considerably also, although these variations do not show so well in undissected material, and they are not dealt with in detail here (figs, 75 and 76; 72 and 78).

Unassociated males representing about 10 different species have been reviewed for this work, but I believe that nothing is gained by assigning new names to undescribed forms, all of which will eventually be tied to their respective female castes. The rearing of live colonies or colony fragments of Anochetus   HNS is to be encouraged, for in this way we are most likely to make the necessary male-female associations.

Probably a knowledge of the male terminalia is needed to resolve completely the difficulties of species distinction existing in such complexes as those of A. inermis   HNS , A. mayri   HNS , A. traegaordhi   HNS and A. graeffei   HNS .

Distribution and Bionomics

There topics have been touched upon for Anochetus   HNS in the respective summaries for subtribe Odontomachiti (A 77-88; the A. inermis   HNS of p. 80 is assigned to A. simoni   HNS in the present section). Anochetus   HNS colonies of all groups appear to contain fewer (usually <100 adult) individuals than do those of Odontomachus   HNS , and this together with their usually smaller body size tends to adapt them to living in cryptic sites of low volume, such as are available in rotten twigs in humus or forest litter, crevices in bark or rotten logs, hollow twigs in trees, palm leaf-base interstices, or small excavations in the soil.

Compared to Odontomachus   HNS , then, Anochetus   HNS species tend to be «interstitial» and more specialized in their microhabitat selection and lifeways; their environment is coarse-grained. We should recognize, meanwhile, that many of the species forage rather widely for their size, and ground- or rotten wood-nesting species often can be found well above ground level on forest or savanna woodland tree trunks, but in most cases after dark (e.g., africanas). Other species (e.g., levaillanti   HNS ) may nest in the soil in arid areas, and forage over the ground surface near midday in only scanty shade. Probably, though, most species are nocturnal foragers.

Still other species, perhaps including emarginatus   HNS , pellucidus   HNS , fuliginosus   HNS and faurei   HNS , appear to be more or less arboreal nesters and foragers, though we have scanty, merely suggestive data on this point.

Anochetus   HNS species are all certainly predaceous; the natural extent of their feeding on honeydew and other sugar sources is totally unknown. The mechanism of their trap-mandible is similar to that of Odontomachus   HNS ( Marcus, 1944, 1945), and like that genus, they can «jump» backwards by snapping the jaw-apices against smooth, unyielding objects. As befits their prevailingly small body size, Anochetus   HNS species tend to respond to massive disturbances with lethisimulation rather than the aggressive biting and stinging reactions of Odontomachus   HNS . On the whole, Anochetus   HNS species are slower and more deliberate in their hunting behavior than are Odontomachus   HNS , and more often tend to employ waiting-and-ambush tactics in securing their prey. Nothing substantial is known about their possible prey specificity. In fact, the biology of Anochetus   HNS is a subject wide open to all kinds of investigation.

Anochetus   HNS ranges about as far south as Odontomachus   HNS in South America (to northern Argentina) and Australia (to arid inland parts of Victoria and southwestern Australia), but reaches farther south in South Africa (at least to Port Elizabeth in the eastern Cape Province). In the Northern Hemisphere, it gets to Morocco, Tunisia, and even the extreme southern point of Spain, beyond the range of Odontomachus   HNS , and in the Middle East, A. evansi   HNS occurs in Kurdistan, but, like Odontomachus   HNS , Anochetus   HNS is limited northward in India and Pakistan by the Himalayas and Pamirs. In China, Anochetus   HNS is still known only from Kwangtung and Hainan, in the far south, whereas Odontomachus monticola   HNS ranges far to the north, even beyond Peking. In the Pacific, A. graeffei   HNS is widespread, undoubtedly through the agency of human commerce, and it reaches central Polynesia and Micronesia with Odontomachus simillimus   HNS .

In North America, Anochetus   HNS fails to extend northward beyond tropical Mexico and the Bahamas, while Odontomachus   HNS reaches Arizona, central Texas and southern Georgia. The differences in distribution between these two genera indicate that Odontomachus   HNS does somewhat better than Anochetus   HNS at producing species that can penetrate colder climates, but that Anochetus   HNS may have the edge in evolving species adapted to aridity. Both genera, of course, are predominantly tropical and forest-inhabiting.

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Hymenoptera

Family

Formicidae

Loc

Anochetus

Brown, WL Jr., 1978
1978
Loc

Myrmapatetes

Wheeler 1929: 6
1929
Loc

Stenomyrmex

Mayr 1862: 711
1862
Loc

Anochetus

Mayr 1861
1861
Loc

Odontomachus ghilianii

Spinola 1853
1853
Loc

Myrmecia

Fabricius 1805
1805
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