Bioacoustics of Formicidae

1 Clypeus broadly inserted between frontal lobes, which appear flattened in frontal view (Fig. A). Antennal sockets widely sep- arated.............................................................................................. 2 - Clypeus usually narrowly inserted between frontal lobes (Fig. B). Antennal sockets usually closely approximated........ 3 2(1) Mandibles subtriangular, with numerous short teeth (Fig. A)........................................... Platythyrea - Mandibles with three long and attenuated teeth (Fig. B)......................................... Thaumatomyrmex 3(1) Metapleural gland orifice with a posterior, inverted U-shaped cuticular lip (opening lateral and anterior of posterior propodeal face) (Fig. A)........................................................................................ 4 - Metapleural gland orifice without a posterior U-shaped cuticular lip (opening separated from posterior propodeal face by a very narrow, low flange) (Fig. B)........................................................................ 9 4(3) Propodeal spiracle slit-shaped (Fig. A).................................................................... 5 - Propodeal spiracle round or ovoid (Fig. B)................................................................. 7 5(4) Massive ants (head width greater than 4.0 mm). Anterior clypeal margin with a pair of large projecting teeth (Fig. A).................................................................................................. Dinoponera - Smaller ants (head width less than 4.0 mm). Anterior clypeal margin without a pair of large projecting teeth (Fig. B)...... 6 6(5) Hypopygium with a row of stout setae along each side of the sting (sometimes partially hidden by surrounding thinner hairs) (Fig. A). Stridulatory organ absent from A4 pretergite. Arolia not prominent and white. Preocular carinae absent..................................................................................................... Pachycondyla - Hypopygium without a row of stout setae along each side of the sting. Stridulatory organ present on A4 pretergite (Fig. B). Arolia prominent, projecting and usually bright white. Preocular carinae present or absent............ Neoponera (in part) 7(4) Ventral apex of the metatibia with a single spur, which is pectinate (Fig. A)................................ Simopelta - Ventral apex of the metatibia with a large pectinate spur and a smaller simple spur (Fig. B).......................... 8 8(7) Metanotal groove strongly developed and angular, the propodeum well below the mesonotum (Fig. A)........ Mayaponera - Metanotal groove essentially absent to weakly developed, the propodeum level with the mesonotum (Fig. B).................................................................................................. Neoponera (in part) 9(3) Mandibles long and straight, inserted medially on the front of the head. Head with prominent ocular prominences (Fig. A) 10 - Mandibles inserted toward the sides of the front of the head. Head without prominent ocular prominences (Fig. B)...... 11 10(9) Nuchal carina continuously curved, the posterior surface of the head lacking a pair of dark apophyseal lines (Fig. A).................................................................................................... Anochetus - Nuchal carina medially V-shaped, the posterior surface of the head with a pair of dark converging apophyseal lines (Fig. B)........................................................................................... Odontomachus 11(9) Mesotibiae dorsally with abundant stout traction setae (Fig. A)................................................ 12 - Mesotibiae dorsally without abundant stout traction setae (a few stout setae sometimes present near tarsus but never extending along length of tibia) (Fig. B).......................................................................... 13 12(11) Eyes absent in workers, but present in queens. Metapleural gland orifice opening laterally. Head and body without a dense pubescence. Mandible with a basal groove (Fig. A)................................................ Centromyrmex - Eyes usually present in both workers and queens (rarely absent in workers). Metapleural gland orifice opening posteriorly at the posteroventral corner of the metapleuron. Head and body covered by a dense pubescence. Mandible without a basal groove but often with a basal pit (Fig. B)................................................................ Cryptopone 13(11) Ventral apex of the metatibia with both a large pectinate spur and a smaller simple spur (Fig. A)..................... 14 - Ventral apex of the metatibia with a single spur, which is pectinate (Fig. B)...................................... 17 14(13) Tarsal claws usually pectinate, rarely armed with one to three preapical teeth (Fig. A)...................... Leptogenys - Tarsal claws unarmed (Fig. B)......................................................................... 15 15(14) Mesosomal profile discontinuous, the propodeum lower than the mesonotum. Mandible with a basal pit or groove. Propodeal spiracle round. Prora absent from anterior margin of first gastral sternite (Fig. A) (Introduced in SE USA ).... Brachyponera - Mesosomal profile nearly continuous, the metanotal groove shallow or absent. Either mandible without a basal pit or groove and propodeal spiracle round or ovoid, or mandible with a basal pit or groove and propodeal spiracle slit-shaped. Prora present on anterior margin of first gastral sternite (Fig. B).......................................................... 16 16(15) Mandible with a basal groove (occasionally weakly developed). Propodeal spiracle slit-shaped (Fig. A)...... Pseudoponera - Mandible without a basal groove (but a ridge sometimes present). Propodeal spiracle round or ovoid (Fig. B)..... Rasopone 17(13) Mandibles narrow, with several long attenuated teeth (Fig. A)......................................... Belonopelta - Mandibles triangular and without long attenuated teeth (Fig. B)............................................... 18 18(17) Subpetiolar process with an anterior fenestra and paired posteroventral teeth (Fig. A).......................... Ponera - Subpetiolar process without both an anterior fenestra and paired posteroventral teeth (Fig. B)............... Hypoponera

Worker monomorphic, dimorphic, or polymorphic, often very strongly so; the soldier form having a very large head and strong mandibles. Frontal carinae nearly always separated, rarely close together; divergent or slightly convergent behind and rarely lobed anteriorly; usually the clypeus is wedged in between the frontal carinae; in the Metaponini and a few other forms the clypeus is not prolonged back, its posterior margin being rounded. Antennae from 4- to 12-jointed, often with a distinct club. Ocelli frequently absent in the ordinary worker, though in strongly dimorphic species they may still be more or less distinct in the soldier. Pedicel formed by the petiole and the postpetiole; very rarely ( Melissotarsus ) the postpetiole is nearly as wide as the basal segment of the gaster. Stridulatory organ usually present at the base of the gaster. Sting developed. Spurs of the middle and hind tibiae in the majority of cases simple or absent; pectinate in the Metaponini and Myrmicini only. Gizzard simple and tubular in most genera and of a very primitive type compared with the conditions in the Dolichoderinae, Camponotinae, and Pseudomyrminae. Female usually winged and larger than the worker; in a few cases ergatoid; true dichthadiiform queens are not known, but in some parasitic genera ( Anergates , Anergatides ) the gaster of the fertile female becomes enormously distended. Male usually with the copulatory armature partly exserted; entirely retractile in a few genera of the Solenopsidini only. Anal segment with cerci. In a few cases (as in certain species of Cardiocondyla ) ergatoid, wingless males are known, sometimes together with winged individuals. Antennae almost always 13-jointed, even when the worker and female have very few antennal joints (11-jointed in Stereomyrmex and Cataulacus ; 12-jointed in Metapone , certain Attini, Meranoplini, etc.). The venation of the fore wing offers much diversity. In some genera the more primitive type is still retained, with a closed radial, two closed cubital cells, and a closed discoidal cell, but all degrees of reduction are met with. When there is only one cubital cell, the cubitus may be united with the radius by means of a long intercubitus(type of Solenopsis ) or the intercubitus may disappear, the cubitus and radius being fused in a spot or for some distance (type of Formica ). Larva thick-bodied, orthocephalic, without exudatory papillae around the mouth. The body is, as a rule, abundantly covered with chitinous hairs of very different kinds; dorsal oncochaetae often present. Nymphs never enclosed in a cocoon.