The Ants of
Africa SUBFAMILY PONERINAE - Genus Anochetus |
|
Contents - Ponerinae - PONERINAE Introduction |
In Tribe PONERINI
Diagnostic Features - Similar to Odontomachus but with the apical mandibular armament with the dorsalmost tooth acute and the petiolar node not ending dorsally in a spine. See Brown (1978c).
Anochetus Mayr (1861: 53; type species Anochetus ghilianii as Odontomachus
ghilianii Spinola, 1851b: 55, by monotypy);
junior synonym Stenomyrmex Mayr (1862: 711; type species Myrmecia
emarginata, by subsequent designation of Wheeler (1911f: 173; type
location Central America); synonymy by Brown (1978c: 552).
Mayr's (1861) genus description is at ; and his (1896) definiton of the male at .
Brown (1978c) revised the genus and I have followed his synonymies and so-on. The revision is poor on descriptions, etc., and leaves much to be desired. For instance, one gets the impression that he paid little attention to the work of Bernard (1952). What little is known of their general biology was summarised by Brown (1978c). The colony size is of the order of 100 individuals, usually in cryptic sites - rotten or hollow twigs, under bark, etc. Some including pellucidus and fulginosus apparently are more or less arboreal. Most forage after dark, often widely, and all certainly are predaceous. If attacked their general response is to feign death. Probably all are predaceous, utilising a trap-jaw mechanism to seize prey and to "jump" backwards. Brown (1978c) regarded the genus as most likely having its origin in the Old World wet tropics, with arid-country species restricted to that global area. Brown's key is at and .
Examples of queens and males can be seen on Anochetus katonae, Anochetus pellucidus and Anochetus species Sevare
Key to workers of species from Africa
Developed from Brown (1978c); note CI = 100 X HW/HL but in my
experience it is not a reliable index; HL in the key includes mandibles.
0 | Wholly
unique in having a dense covering of semi-decumbent fine pilosity all
over, including the legs and scapes; inner margin of mandibles with two
distinct edges; petiole with a moderately thick profile with a rounded
apex, in front view the upper margin is weakly concave; TL ca 5 mm,
eyes ca 0.27 |
Cameroun - Anochetus
hirsutus
nsp |
1 | In full face view, antennal scapes fail to reach posterior margin of occipital lobes, eyes < 0.15 mm | 2 |
-- | In full face view antennal scapes extend beyond posterior margins of occipital lobes and/or compound eyes > 0.15 mm long | 6 |
2 | Petiole node in lateral view quite thick with near parallel sides; TL 3.5-3.9 mm; slightly reddish-yellow | South Africa - talpa |
-- | Petiole node in lateral view strongly tapered from bottom to top | 3 |
3 | Petiolar node in lateral view with apex narrowly rounded (as preceding), puncturation of first gastric tergum fine and inconspicuous | 4 |
-- | Petiolar node in lateral view tapered to a sharp apex, puncturation of first gastric tergum usually coarse and conspicuous | 5 |
4 | HL (including mandibles) > 1.50 mm; petiole in anterior view with narrow rounded apex; TL 4.5-4.8 mm; yellowish brown, alitrunk, antennae and mandibles reddish brown | . |
. | South Africa - jonesi | |
-- | HL (including mandibles) < 1.50 mm; petiole in anterior view with wide rounded apex; TL 3.7-3.8 mm; reddish-yellow, shiny | . |
. | South Africa - punctaticeps | |
5 | Eyes reduced to dots 0.10 mm or less in greatest diameter, filling half or less of the length of the orbital fossa; mesonotal disc straplike, about three times as wide as long; TL 3.9-4.4 mm; colour clear yellow | . |
. | West Africa & Gabon - siphneus | |
-- | Eyes usually larger (0.07-0.12 mm long) filling more than half the length of the orbital fossa; mesonotum < 2.5 times as wide as long; TL 3.3-3.5 mm; colour brownish-yellow to dark brown, head often lighter | . |
. | Pan-African - katonae | |
relatively long antennal scapes and larger eyes | -- | |
6 | Upper surfaces of body with conspicuous uniform appressed or subappressed pubescence; standing hairs absent or extremely sparse | 7 |
-- | Upper surfaces of body with little or no appressed pubescence, standing hairs usually more abundant | 9 |
7 | Small, HL < 1.9 mm, with reduced eyes; petiole node a narrow tapering scale in lateral view; TL 4.9 mm; castaneous, gaster darker | . |
. | eastern Africa - pubescens | |
-- | Larger, HL > 1.9 mm, large eyes; petiole node a thick scale in lateral view | 8 |
8 | First tergite of gaster and most of rest of body smooth and shining; TL 6.0-6.5 mm; dull ferruginous, gaster darker | northern savannah - sedilloti |
-- | First tergite of gaster with rugulose sculpture, rest of body dull, much striated; TL 5.2-6.0 mm; mostly rich dark red, gaster with basal segment castaneous and rest piceous to black | east and southern Africa - levaillanti |
Generally lacking pubescence | -- | |
9 | Frontal striation of head distinct, prevailingly longitudinal and continuous to or very nearly to the nuchal carina in the middle | 10 |
-- | Frontal longitudinal striation of head not reaching nearly to nuchal carina, the vertex largely smooth and shining | 15 |
10 | Gastric terga I and II completely glassy smooth and shining, only scattered puncturation; frontal striation always fine, seven or more striae/0.1 mm transect; head broad CI > 87 | 11 |
-- | Gastric terga I and II with some reticulate, rugulose or dense punctulate sculpture; frontal striation of head coarse or fine, head varying in width, CI 80-89 | 13 |
11 | Dorsum of pronotum smooth and shiny; black with head and appendages reddish | . |
. | East & Central Africa - obscuratus | |
-- | Dorsum of pronotum sculptured | 12 |
12 | Dorsal alitrunk with variable moderate sculpturation; eyes 0.18-0.26 mm long; TL 5.7 mm; castaneous but legs yellow | . |
. | West Africa & Congo Basin, east into Uganda forests - africanus | |
-- | Dorsal alitrunk with fine superficial striation, pronotum near smooth; eye 0.27-0.28; TL 5.9 mm; head dark reddish-amber, alitrunk and gaster castaneous brown, legs paler | South Africa - natalensis |
13 | Frontal striation of vertex fine and regular; head more or less red in colour, body darker; TL West Africa 4.6 mm, TL South Africa 5.3-5.5 mm | . |
. | West Africa & Congo Basin - bequaerti | |
-- | Frontal striation usually coarse and uneven; head and body concolorous | 14 |
14 | Colour black or piceous, with brownish-yellow mandibles, antennae and tarsi; propodeum rugulose; TL ca 6.0 mm | . |
. | pan-African - fuliginosus | |
-- | Colour tawny-yellow, with lighter appendages, having a somewhat translucent appearance; propodeum usually densely punctate, opaque; rarely partly rugulose; TL ca 5.0 mm | . |
. | West Africa & Congo Basin - pellucidus | |
--Head with short or no longitudinal striation | -- | |
15 | Petiole elongate, with bidentate summit; TL 10 mm; pale to reddish pale brown | . |
. | South Africa - faurei | |
-- | Petiole summit unarmed | 16 |
16 | Petiole node in lateral view thick with rounded apex; eye > 0.35 mm long; TL 8.3-9.1 mm; dull brownish yellow | . |
. | Angola - angolensis | |
-- | Petiole node compressed with level apex; eyes < 0.35 mm long | 17 |
17 | Propodeum entirely smooth and shining; TL ca 6.0 mm; pale brownish or yellowish red, appendages yellowish | North-east Africa west to Senegal - rothschildi |
-- | Propodeum sculptured | 18 |
18 | Petiole
node in profile peg-like, anterior slope rounded, summit bluntly
rounded, seen from above lunate, mostly dull yellow, trunk darker Note this definition (Brown, 1978) is for workers that differ markedly from the type queen. |
. |
. | West Africa & Congo Basin - maynei | |
Note:
the separation that follows appears to be far from definitive with a
considerable variation in form, eye size, pubescence, etc. |
||
-- | Petiole node variable, anterior slope usually convex or straight, or if slightly concave summit strongly tapered; TL 6.8 mm; brownish red-gold | . |
. | pan-African - traegaordhi | |
-- | TL ca 6.5 mm; petiole
node subtriangular with the summit narrowly but bluntly
rounded; shiny brownish yellow, gaster slightly darker; with only very
short inconspicuous pubescence and almost no erect hairs |
. |
. | Congo Basin - sudanicus | |
-- | Eye small, length generally less than 0.20 mm |
. |
. | Spain, North Africa & Senegal (?) - ghilianii |
Anochetus new speciesFour specimens were found in two leaf litter samples from logged sites at Atewa Forest Reserve, Ghana (Belshaw & Bolton, 1994b). |
PONERINAE Introduction |
© 2007, 2008, 2009, 2010, 2011, 2013 - Brian Taylor
CBiol
FSB FRES 11, Grazingfield, Wilford, Nottingham, NG11 7FN, U.K. |
href="anochetus.htm"