Subfamily Myrmicinae

1. Subfamily Myrmicinae Compiled by Hilda Taylor • Subfamily Myrmicinae • General Characteristics: Habitat: • Largest subfamily - Deserts to tropical forests • - Members of this subfamily have stingers or • have modified stingers • - Petiole and postpetiole are present • - Origin of the antennae is covered by lobes and • lobes continue into the frontal carinae • Behavior: • - Aggressive to docile

2. Spines on Body Tubercles Genus Acromyrmex (Fungus Growing Ants) • Descriptive Characteristics: Habitat: • Antennae with 11 segments - Mostly grasslands, also in deserts • Body covered with spines - Common in tropics • Gaster with tubercles (bumps) - Feed on fungus they grow • Polymorphic - Possibly feed on juices of the plants they cut • Behavior: • Cut grass to grow fungus • Cut leaves of Stinking Gourd (Cucurbita foetidisima), • in Chihuahuan Desert • Aggressive, they bite • Note: Bigger than Trachymyrmex, spp.

3. Spines Long Legs Genus Aphaenogaster • Descriptive Characteristics: Habitat: • Slender elegant ants - Chihuahuan Desert • Long legs - Mexico – Mountains in Veracruz • Spines on propodeum normally or • angled structures • 12 segmented antennae • Behavior: • Active early in the morning and • late in the evening • - Aggressive

4. Genus Atta Leaf Cutting Ants • Descriptive Characteristics: Habitat: • 11 segmented antennae - Found in tropical forests: • Big shinny head = South America in Argentina • Strongly polymorphic: and Brazil • = soldiers are very different from = Mexico • tiny workers = USA in East Texas (oak forests), • = need soldiers for identification Oregon Pipe Cactus in Arizona • Behavior: • Aggressive, specially big workers • Grow fungi

5. Genus Cardiocondyla Spines/Angles Rounded Petiole Penducle • Descriptive Characteristics: Habitat: • 12 segmented antennae - New World, South America up • Clypeus sticks up like a point above mandibles to Brazil • Propodeum with spines or angles - Found all over the place: • Penducle – long = tropics • Petiole – rounded smoothly = deserts (Indio in pitfalls) • Tiny ants = California (C. etiopa) • Males look like workers, but have big mandibles - Nest in the ground • and have no wings • Behavior: • Not aggressive, too small

6. Genus Cephalotes Spines Note: As of 2000 the above were synonymized with genus Cephalotes Minor Worker Major Worker • Descriptive Characteristics: Habitat: • Head, mesosoma and propodeum with spines - Tropical, mesic habitats • Very large ant, beautiful ant - Mexico • Polymorphic - USA in Arizona, but very rare • Dark brown, dull - Nest in big dead branches (~ 2” • Zacryptocerus spp.also has lateral spines on in diam) and hollow twigs • the body - Nest possibly in termite mounds • Behavior: • Not aggressive, do not sting • Move jerky-like

7. Genus Crematogaster Acrobat Ants • Descriptive Characteristics: Habitat: • Gaster looks like a heart - USA and Mexico • Petiole is hooked up to top part of the gaster - Found everywhere: • Monomorphic: = under rocks, ground, trees, twigs • = males and females look the same = Chih. Desert on Creosote bush • = bicolor, brown and yellow (Larrea tridentata) • Raise gaster over the mesosoma when placed • in alcohol (same as Azteca, spp) • Behavior: • Aggressive, can sting but does not hurt much • Sting sprays paint as defense mechanism

8. Frontal Carina Tubercles Bumps Lobe Genus Cyphomyrmex • Descriptive Characteristics: Habitat: • Head: - Ranges from north New Mexico to • = Lobes hide the point of origin of the antennae and Argentina • join with the frontal carinae. - Common in tropical forests, also • = The carinae extend all the way back of the head in arid zones like the Chihuahuan • = Rounded structures on top of head resemble horns Desert • - Alitrunk – full of bumps, may have tiny spines - Use dung from catepillars as • Gaster – tubercles similar to Acromyrmex, spp., substrate for fungus • but not as sharp • Behavior: • - Not aggressive • - Slow • - Play dead

9. Genus Leptothorax Spines (Most common ant) Spines Peduncle Leptothrax Spines spine Peduncle • Descriptive Characteristics: Habitat: • 11 or 12 antennal segments - Found everywhere: • Antennal club has 3 segments = under rocks, dead logs, in the • Mexican species have no spines, all others do ground, in roots • Macromischa, spp – 11 antennal segments, convex - Some are parasitic on other ants • alitrunk and have very long peduncle (Mex.) - Common • Nesomyrmex, spp – 11 or 12 antennal segments, - L. whitford lives in branches • petiole and postpetiole covered with spines (Mex.) • Behavior: • - Not aggressive if left alone • - L. whitford is the only aggressive species

10. Depression Rounded Comb-like Genus Manica • Descriptive Characteristics: Habitat: • Same group as Pogonomyrmex (they are Harvester ants) - USA in north New Mexico, • = Pogonomyrmex, Myrmica, and Manica have Colorado, California • comb-like tibial spurs (pectinate) on mid and hind legs - May not find in Mexico • 12 segmented antennae - Nest in the ground in pine and • Depression present between mesonotum and and juniper forests • propodeum • -Rounded petiole • Behavior: • - Docile, do not sting

11. Oval head Rounded Same shape Genus Megalomyrmex • Descriptive characteristics: Habitat: • 12 segmented antennae - Tropical • 3 segmented club - Not in the USA • Oval head - Found under rocks nesting in the soil • Yellowish color, smooth and shinny pretty blond ants - May find in Mexico, not common • Big ants ~ ½” long • Petiole and postpetiole have same shape • Rounded mesosoma • Behavior: • - Not very aggressive