1. 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 Compiled by Hilda Taylor

2. 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. Spines on Body Tubercles

3. Genus Aphaenogaster Spines Long Legs 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 Penducle Rounded Petiole 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 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 Note: As of 2000 the above were synonymized with genus Cephalotes Minor Worker Major Worker

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. Genus Cyphomyrmex Frontal Carina Lobe Bumps Tubercles 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 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 Leptothrax Spines spine Peduncle (Most common ant)

10. Genus Manica Depression Rounded Comb-like 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. 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 Rounded Same shape Oval head