Key to the Anochetus Species of Asia, Melanesia and the Pacific Region

This worker key is based on: Brown, W. L., Jr. 1978. Contributions toward a reclassification of the Formicidae. Part VI. Ponerinae, tribe Ponerini, subtribe Odontomachiti. Section B. Genus Anochetus and bibliography. Studia Entomologica. 20:549-638. The key also includes an update to the rugosus group given by: Satria, R., Viet, B.T., Eguchi, K. 2017. New synonymy and redescription of Anochetus mixtus Radchenko, 1993, and distinction from the other members of the Anochetus rugosus group (Hymenoptera: Formicidae: Ponerinae). Asian Myrmecology 9: e009006 (DOI 10.20362/am.009006).

This key is slightly outdated but is the best available for the genus.

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1

Mesial edge of mandible for much of its length with a single margin bearing 1 or 2 prominent teeth near midlength, or a close series of coarse dentlcles or teeth on apical half or more . . . . . 2

Mesial edge of mandible with 2 margins up to preapical tooth or angle: dorsal margin edentate (except for the single preapical tooth or angle, when this is present); ventral margin denticulate, crenulate, or smooth . . . . . 8

2

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Mandible with 2 large submedian teeth on mesial margin, the distal tooth larger than the proximal (Sri Lanka) . . . . . Anochetus nietneri

Mandible with a single large submedian tooth (New Guinea) . . . . . 3

Mandible with a close series of 4 or more teeth along the mesial edge . . . . . 4

3

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Striation of vertex reaching nuchal carina; central part of pronotum striate or rugulose, though the sculpture may sometimes be weak and nearly smooth in the anterior part of the disc; free corners of petiolar node rounded to sub-rectangular (Papua New Guinea) . . . . . Anochetus fricatus

Head of Anochetus fricatus worker

Profile of Anochetus fricatus worker

Striation of vertex separated from nuchal carina by a smooth, shining strip; disc of pronotum completely smooth and shining in the middle (except for small, scattered punctures); free corners of petiolar node produced as acute teeth (NE New Guinea) . . . . . Anochetus chirichinii

Head of Anochetus chirichinii worker

Profile of Anochetus chirichinii worker

4

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Apex of petiole produced as a tooth or spine . . . . . 5

Apex of petiole narrowly rounded, not toothed . . . . . 6

5

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Large species, length (TL) > 8 mm (Celebes, Moluccas) . . . . . Anochetus gladiator

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Profile of Anochetus gladiator worker

Smaller species, length (TL) < 7 mm (New Guinea: W. Itian) . . . . . Anochetus variegatus

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Profile of Anochetus variegatus worker

6

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pronotal disk entirely coarsely rugose . . . . . 6b
Pronotal disc smooth and shiny . . . . . 7

6b

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Dorsum of head in full-face view largely smooth and shiny, but frons distinctly striate obliquely and longitudinally; mesopleuron smooth and shiny; petiolar node with its basal half weakly striate . . . . . Anochetus mixtus

Dorsum of head in full-face view largely striated (striation extending to nuchal carina); anterior third of mesopleuron finely sculptured; petiolar node largely coarsely rugose . . . . . Anochetus rugosus

Head of Anochetus rugosus worker

Profile of Anochetus rugosus worker

7

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Mandibles longer (MI>60); when head is seen in perfect full-face view, antennal scape surpassing posterior borders of occipital lobes by distinctly more than length of first funicular segment; head narrower (CI<90) . . . . . Anochetus princeps

Head of Anochetus princeps worker

Profile of Anochetus princeps worker

Mandibles shorter (MI<60); when head is seen in perfect full-face view, antennal scape surpassing posterior borders of occipital lobes at most by length of first funicular segment; head wider (CI 90 or more) . . . . . Anochetus muzziolii

Head of Anochetus muzziolii worker

Profile of Anochetus muzziolii worker

8

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Intercalary tooth of mandibular apex small (sometimes worn to an indistinct tubercle, or even missing completely), rising from the dorsal side of the ventral apical tooth well beyond its mid length (measuring length from crotch with dorsal apical tooth) . . . . . (risii group) . . . . . 9

Intercalary tooth present; (center of its base) arising from near the base of the ventral apical tooth, or from near its midlength . . . . . 15

9

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Pronotum sculptured over the entire disc . . . . . 10

Pronotum smooth and shining over at least the large central part of its disc . . . . . 11

10

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Size large, combined length of head and closed mandibles (HL + ML) > 2.5 mm; frontal striation spread over a wide area of the central vertex (Malaya) . . . . . Anochetus tua

Head of Anochetus tua worker

Profile of Anochetus tua worker

Size smaller, HL + ML < 2.2 mm; frontal striation confined to the space between frontal carinae (Luzon) . . . . . Anochetus incultus

Head of Anochetus incultus worker

Profile of Anochetus incultus worker

11

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Very slender, elongate, CI < 83; petiole of particular form; perhaps 2 different species included (Borneo, Malaya) . . . . . Anochetus agilis

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Profile of Anochetus agilis worker

Head broader; CI > 83; petiolar form otherwise . . . . . 12

12

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Petiolar apex tapered gradually into a slender, spiniform tip (NE New Guinea) . . . . . Anochetus peracer

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Profile of Anochetus peracer worker

Petiolar apex narrowly rounded or nipple-like, not spiniform . . . . . 13

13

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Center of vertex extensively striate, the striation extending to within 0.2 mm of the nuchal carina (Malaya: Trengganu) . . . . . Anochetus strigatellus

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Profile of Anochetus strigatellus worker

Frontal striation obsolete or restricted to, or nearly to, space between frontal carinae . . . . . 14

14

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Mandibles long (ML > 1 .0 mm; MI > 68); worker eye L > 0.25 mm (SE China, Vietnam, Java) . . . . . Anochetus risii

Head of Anochetus risii worker

Profile of Anochetus risii worker

Mandibles of medium length (ML 0.70-0.90 mm; MI 57-63); worker eye L 0.16-0.21 mm (Java, Borneo, Philippines. . . . . Anochetus modicus

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Profile of Anochetus modicus worker

Mandibles short (ML < 0.70 mm; MI about 50) ; worker eye L 0.13-0.14 mm (Mindanao) . . . . . Anochetus brevis

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Profile of Anochetus brevis worker

15

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As seen from front view, petiolar node tapered to a bluntly pointed (narrowly rounded or even nipple-like) apex (Melanesia and Philippines) . . . . . cato group . . . . . 16

Petiolar node as seen from front view with summit broadly rounded, transverse or concave . . . . . 18

16

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Frontal striation nearly confined to space between frontal carinae, and not or only slightly extending posteriad beyond the level of the compound eyes . . . . . isolatus superspecies . . . . . 17

Frontal striation extending over a wide area of central vertex and reaching halfway or more of the distance between level of eyes and posteromedian excision of head (N. Guinea, Bismarck Arch., Solomon Is.) . . . . . Anochetus cato

Head of Anochetus cato worker

Profile of Anochetus cato worker

17

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Body color dark reddish-brown to yellowish brown (in callows?); HL + ML rarely if ever > 3.0 mm (Melanesia, Philippines) . . . . . Anochetus isolatus

Head of Anochetus isolatus worker

Profile of Anochetus isolatus worker

Head, trunk and node piceous; gaster and appendages reddish-brown; HL + ML slightly > 3.0 mm (Waigeo I., W. Irian; doubtfully distinct from isolatus) . . . . . Anochetus seminiger

Head of Anochetus seminiger worker

Profile of Anochetus seminiger worker

Head dark brown or piceous; rest of body light ferruginous to ferruginous yellow; propodeal costulae partly effaced, the surface here smooth and shining (Caroline Is.: Yap) . . . . . Anochetus splendidulus

18

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Pronotal disc (at least a broad central field) and all of first gastric tergum smooth and shining when clean, with at most fine, spaced punctures . . . . . 19

Pronotal disc coarsely striate or punctate-rugulosej smooth interspaces, if any narrow and usually coarsely punctate; first gastric tergum rugulose, .striate or smooth, with or without coarse punctures . . . . . 25

19

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Modest- or small-sized, lightly pigmented species with reduced eyes: comp0und eye L < 0.15 mm. their greatest diameter < maximum W of a mandible . . . . . 20

Larger species with large eyes: eye L > 0.25 mm and > maximum W of a mandible . . . . . 24

20

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Propodeal angles produced as a pair of short teeth or tubercles . . . . . 21

Propodeal angles rounded. Unarmed; trunk with sculpture effaced smooth and shining, except for the delicately cross-striate propodeal declivity (W. Iran) . . . . . Anochetus evansi

Head of Anochetus evansi worker

Profile of Anochetus evansi worker

21

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HL + ML > 1.55 mm . . . . . 22

HL + ML < 1.55' mm . . . . . 23

22

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Mesonotal disc > twice as wide as long; mesonotal suture deeply impressed (Malaya: Perak) . . . . . Anochetus myops

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Profile of Anochetus myops worker

Mesonotal disc not more than twice as wide as long; meso-metanotal suture distinct .. but not deeply impressed (Sri Lanka) . . . . . Anochetus longifossatus

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Profile of Anochetus longifossatus worker

23

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Tiny species: HL + ML < 1 .25 mm; mesonotal disc > twice as wide as long (S India) . . . . . Anochetus pupulatus

Head of Anochetus pupulatus worker

Profile of Anochetus pupulatus worker

Slightly larger species: HL + ML of holotype about 1.5 mm; mesonotal disc not > twice as wide as long (Taiwan) . . . . . Anochetus subcoecus

24

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Petiolar node axially compressed above; anterior slope concave, and summit rather bluntly rounded as seen from the side, but strongly transverse aa seen from above; body with very numerous short, fine, erect hairs; appressed pubescence scarcely developed on head, trunk, petiole and gaster; in full-face view of head, antennal sea pes surpass posterior borders of (occipital lobes by at least an apical scape width (S India: Madras State) . . . . . Anochetus rufus

Head of Anochetus rufus worker

Profile of Anochetus rufus worker

Petiolar node thick, erect, barrel-shaped; anterior slope convex, summit broadly rounded in both directions and only slightly broader than long; body with few or no erect hairs, except for those on apex and underside of gaster (0-9 standing hairs on trunk and first gastric tergum), but with abundant and conspicuous appressed pubescence; when head is viewed full-face, antennal scapes do not reach, or at least do not distinctly surpass, posterior borders of occipital lobes (W peninsular India; see also key to species of Africa, etc.) . . . . . Anochetus sedilloti

Head of Anochetus sedilloti worker

Profile of Anochetus sedilloti worker

25

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Petiolar node as seen from the side thin, tapered to a very narrowly rounded, or even sharp, apex; scale-like part near its base not more than 0.20 mm long . . . . . graeffei group . . . . . 26

Petiolar node as seen from the side thick, with broadly rounded summit, and L > 0.25 mm near base of erect part of node . . . . . orientalis group . . . . . 27

26

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HL + ML < 1.75 mm; eye L maximum 0.20 mm, usually much less (see key to Australian species; India to Melanesia, N & E Australia and S Polynesia) . . . . . Anochetus graeffei

Head of Anochetus graeffei worker

Profile of Anochetus graeffei worker

HL + ML < 1.75 mm; eye L > 0.20 mm; most of vertex smooth and shining, the frontal striation extending only a short distance beyond the level 01 the eyes (Sri Lanka) . . . . . Anochetus yerburyi

Head of Anochetus yerburyi worker

Profile of Anochetus yerburyi worker

HL + ML 1 .75 mm or more; eye L 0.20 mm or more; frontal striation reaching all the way to nuchal Carina (java), or most of the way (Sikkim, Hainan I.) . . . . . . . . . . . . . . problem samples: <large graeffei>, etc.

27

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First gastric tergum densely and more or less opaquely sculptured over at least the anterior hall . . . . . 28

First gastric tergum smooth and shining, with only scattered, fine piligerous punctures (Sri Lanka, India) . . . . . Anochetus madaraszi

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Profile of Anochetus madaraszi worker

28

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Anterodorsal margin of petiolar node slightly produced anteriad, overhanging the anterior slope, which tends to be concave, trunk red; first gastric tergum black or piceous, coarsely punctate-striate and opaque to near posterior border (SW India) . . . . . Anochetus kanariensis

Head of Anochetus kanariensis worker

Profile of Anochetus kanariensis worker

Anterodorsal margin of petiolar node broadly rounded, like posterodorsal margin; anterior slope of node convex or straight as seen from the side trunk, petiole and gaster piceous or blackish, often with bluish opalescence, the first gastric tergum with punctate-rugulose sculpture thinning to nearly smooth and shining on posterior half or third of the segment

-(S Vietnam) . . . . . Anochetus orientalis