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Taxonomy
Formicidae
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In some parts of the world, including the United States, ant species have been accidentally brought in from other continents. These invader ants are causing a lot of problems.
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Source | http://www.biokids.umich.edu/critters/Formicidae/ |
Ants
Ants are small.
But ants don't have a beard at all.
They're under the ground almost all the time,
But they just don't know how to rhyme.
Out your door and beneath your feet,
They're digging nonstop, with every heartbeat!
- Poem written by William in Ms. McCurdy's 3rd Grade Class, North Falmouth Elementary School.
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Rights holder/Author | Anne Thessen, Anne Thessen |
Source | No source database. |
Morphological terminology follows Bolton (1994), on which much of this key is based. The term mesosoma is used in preference to alitrunk, to refer to the body part formed from fusion of the thorax and the first abdominal segment (i.e., thorax + propodeum). The promesonotum is that part of the mesosoma composed of the pronotum and the mesonotum. Metasoma refers to the apparent abdomen, comprising the segments posterior to the propodeum, i.e., abdominal segment 2 and succeeding segments. In ants abdominal segment2 forms a node- or scale-like petiole, which is separated by a constriction from the rest of the metasoma. In some species abdominal segment 3 is also node-like and in this case it is said to form a postpetiole.
The key has been designed to apply only to those ant species occurring in California but it should also work for most of western North America, excluding Arizona and New Mexico where additional genera occur.
1 Postpetiole present: abdominal segment 3 separated from segment 4 by a strong constriction and distinctly smaller in size, so that anteriorly the metasoma has two nodelike segments, the petiole and postpetiole .................................................................... 2
- Postpetiole absent: abdominal segment 3 separated from segment 4 by a weak to moderate constriction or by none at all, and when viewed in profile not distinctly smaller in size (height) than segment 4; metasoma anteriorly with a single, isolated node-like or scale-like segment ....................................................................................................... 26
2 Eye reduced to a single ommatidium or absent; antennal insertions fully exposed in a full-face view of head ( Ecitoninae ) ........................................ Neivamyrmex Borgmeier
- Eye very rarely reduced, usually consisting of multiple ommatidia; antennal insertions not fully exposed, covered partially by frontal lobes or medial extensions of the antennal sclerites, when the head is observed in full-face view ........................................... 3
3 Eye very large, eye length about one-half of head length (excluding mandibles); pronotum freely articulating with mesonotum ( Pseudomyrmecinae ) ............................. ....................................................................................................... Pseudomyrmex Lund
- Eye less than one-half head length; pronotum fused with mesonotum ( Myrmicinae ) ... ....................................................................................................................................... 4
4 Antenna with 6 segments, including a 2-segmented club ............................................. 5
- Antenna with 10 segments, including a 2-segmented club ......... Solenopsis Westwood
- Antenna with 11 segments; club variable ..................................................................... 6
- Antenna with 12 segments; club variable.. ................................................................ 14
5 Mandible elongate and linear, with an apical fork of two spiniform teeth ...................... ...................................................................................................... Strumigenys F. Smith
- Mandible short and subtriangular, with a multi-denticulate masticatory margin ........... ............................................................................................................... Pyramica Roger
6 Postpetiole attached to the dorsal surface of the following abdominal segment; petiole dorsoventrally flattened, not node-like in profile ........................... Crematogaster Mayr
- Postpetiole attached to the anterior face of the following segment; petiole node-like in profile, not dorsoventrally flattened ............................................................................. 7
7 Head in lateral view with a diagonal carina running from above the eye down toward the mandibular insertion; promesonotum with conspicuous tubercles or spines ......... 8
- Head in lateral view lacking such a diagonal carina; promesonotum without conspicuous tubercles or spines .................................................................................................9
8 Frontal lobes expanded laterally and covering the sides of the head below the eyes, in full-face view; body lacking erect pilosity.................................... Cyphomyrmex Mayr
- Frontal lobes not expanded laterally to cover the sides of the head; body with erect pilosity.............................................................................................. Acromyrmex Mayr
9 Antenna with a distinct 2-segmented apical club............................... Wasmannia Forel
- Antenna lacking a distinct 2-segmented apical club, either 3-segmented or indistinct.. .....................................................................................................................................10
10 Eye absent or rudimentary; propodeum unarmed, basal face rounding into declivitous face ................................................................................................ Solenopsidininew genus
- Eye well developed, with multiple ommatidia; propodeum angulate or spinose.......11
11 Lateral portions of clypeus, in front of the antennal insertions, developed in the form of a raised ridge or shield-wall; frontal carinae extending almost to the posterior margin of the head......................................................................... Tetramorium Mayr (part)
- Lateral portions of clypeus not developed as a raised ridge or shield-wall; frontal carinae very short or absent...............................................................................................12
12 Eye with short erect setae projecting between the ommatidia........ Formicoxenus Mayr
- Eye lacking erect setae................................................................................................13
13 Median portion of clypeus with a smooth, longitudinally excavate surface, and lacking carinae .............................................................................................. Leptothorax Mayr
- Median portion of clypeus with several longitudinal carinae......................................... ................................................................................................. Temnothorax Mayr (part)
14 Hind tibial spur finely pectinate (as seen at 50-100x magnification).........................15
- Hind tibial spur simple or absent.................................................................................17
15 Metanotal groove absent or very weakly impressed, not breaking the dorsal profile of the mesosoma; psammophore usually present............................ Pogonomyrmex Mayr
- Metanotal groove present and interrupting the dorsal profile of the mesosoma; psammophore absent...........................................................................................................16
16 Propodeum unarmed; mandible with more than 12 teeth ....................... Manica Jurine
- Propodeum armed with a pair of spines; mandible with 6-10 teeth .. Myrmica Latreille
17 Lateral portions of clypeus, in front of the antennal insertions, developed in the form of a raised ridge or shield-wall; apex of sting with triangular lamellate appendage...... ................................................................................................. Tetramorium Mayr (part)
- Lateral portions of clypeus not developed as a raised ridge or shield-wall; apex of sting without triangular lamellate appendage .....................................................................18
18 Petiole short and sessile, lacking well differentiated anterior peduncle and dorsal node; ventrolateral margin of head with sharp, longitudinal carina extending from mandibular base to posterolateral corner of head........................................... Myrmecina Curtis
- Petiole with anterior peduncle and dorsal node; ventrolateral margin of head without sharp, longitudinal carina ...........................................................................................19
19 Dorsum of head and mesosoma without standing pilosity .......... Cardiocondyla Emery
- Dorsum of head and mesosoma with standing pilosity ............................................... 20
20 Anteromedian portion of clypeus notably elevated and bounded by a pair of carinae that diverge anteriorly ................................................................................................ 21
- Anteromedian portion of clypeus not abruptly elevated and lacking a pair of anteriorly diverging carinae ........................................................................................................ 23
21 Propodeum unarmed ....................................................................... Monomorium Mayr
- Propodeum armed with a pair of teeth or spines ........................................................ 22
22 Antennal club 3-segmented; propodeal spiracle large and located close to the declivitous face of the propodeum, separated from latter by no more than the diameter of the spiracle .................................................................................................. Rogeria Emery
- Antennal club 4-segmented; propodeal spiracle relatively small and separated from the declivitous face of the propodeum by more than the spiracle diameter .......................... ....................................................................................................... Stenamma Westwood
23 Antennal club 3- (rarely 4-) segmented ....................................................................... 24
- Antenna lacking a distinct club ................................................................................... 25
24 In profile promesonotum domed and distinctly elevated above the propodeal dorsum; workers dimorphic ......................................................................... Pheidole Westwood
- In profile entire mesosoma dorsum flat to weakly convex, promesonotum not domed or markedly elevated above the level of the propodeum; workers monomorphic .......... ................................................................................................. Temnothorax Mayr (part)
25 Head narrow, longer than broad; mandible slender and triangular, outer margin not strongly curving towards the midline; psammophore absent ...... Aphaenogaster Mayr
- Head broad, subquadrate; mandible short and thick, outer margin strongly curving towards the midline; psammophore usually present ................................. Messor Forel
26 Pygidium (last visible abdominal tergite) flattened and bordered laterally with a row of peg-like teeth or spines that converge distally ( Cerapachyinae ).... Cerapachys F. Smith
- Pygidium (last visible abdominal tergite) convex and rounded, lacking a row of teeth or spines ..................................................................................................................... 27
27 Distinct constriction between abdominal segments 3 and 4; terga and sterna of abdominal segments 3 and 4 laterally fused ......................................................................... 28
- No constriction between abdominal segments 3 and 4; terga of abdominal segments 3 and 4 overlapping the corresponding sterna, not laterally fused with them ............... 30
28 Articulation of petiole (second abdominal segment) to third abdominal segment very broad; petiole without a distinct posterior face ( Amblyoponinae ) .................................. ..................................................................................................... Amblyopone Erichson
- Articulation of petiole (second abdominal segment) to third abdominal segment narrow; petiole with a distinct posterior face .................................................................. 29
29 Pronotum freely articulating with the mesonotum; abdominal tergite 4 not strongly enlarged and not curved ventrally; apex of metasoma directed posteriorly ( Ponerinae ) ....................................................................................................... Hypoponera Santschi
- Pronotum fused immovably to the mesonotum; abdominal tergite 4 strongly enlarged and curved ventrally; apex of metasoma directed anteriorly ( Proceratiinae ).................. .......................................................................................................... Proceratium Roger
30 Apex of metasoma with a circular orifice, often fringed with short setae (the acidopore) ( Formicinae )...................................................................................................31
- Apex of metasoma with a slit-shaped orifice ( Dolichoderinae )..................................38
31 Antenna with 9 segments ............................................................. Brachymyrmex Mayr
- Antenna with 11 segments ................................................................. Plagiolepis Mayr
- Antenna with 12 segments .........................................................................................32
32 Metapleural gland absent; antennal insertions well separated from the posterior clypeal margin; in profile mesosoma dorsum usually evenly convex........................ Camponotus Mayr
- Metapleural gland present; antennal insertions adjacent to the posterior clypeal margin; in profile promesonotum separated from the dorsal face of the propodeum by a distinct impression .....................................................................................................33
33 Maxillary palp segments 3 and 4 greatly elongated, segment 3 (counting from base) half the head length or more; psammophore present.............. Myrmecocystus Wesmael
- Maxillary palp segments 3 and 4 not greatly elongated, segment 3 much less than half the head length; psammophore absent .......................................................................34
34 Ocelli present; propodeal spiracle elliptical to oval....................................................35
- Ocelli absent or indistinct; propodeal spiracle circular to subcircular.......................36
35 Mandible triangular, with seven or more distinct teeth on the masticatory margin........ ............................................................................................................ Formica Linnaeus
- Mandible falcate (sickle-shaped) and lacking distinct teeth............ Polyergus Latreille
36 Dorsum of head and mesosoma with coarse setae, arranged in distinct pairs; eye situated in relatively anterior position, at or in front of midlength of side of head ............. ............................................................................................ Paratrechina Motschoulsky
- Pilosity on dorsum of head and mesosoma variable, but not arranged as coarse setae in pairs; eye situated in relatively posterior position, behind midlength of side of head ... .....................................................................................................................................37
37 Mandible with six teeth; antennal scape long, surpassing posterior margin of head by more than half its length; mesonotum in dorsal view strongly constricted behind pronotum .............................................................................................................. Prenolepis Mayr
- Mandible with seven or more teeth; antennal scape shorter, surpassing posterior margin of head by less than a third its length; mesonotum in dorsal view not strongly constricted behind pronotum...................................................................... Lasius Fabricius
38 Propodeum with a prominent conical tooth at the junction of the dorsal and declivitous faces; maxillary palp segment 3 elongate, subequal in length to segments 4-6; apical mandibular tooth much enlarged...................................................... Dorymyrmex Mayr
- Propodeum rounded or subangulate at the junction of the dorsal and declivitous faces, but without a conical tooth; maxillary palp segment 3 short, subequal in length to segments4; apical mandibular tooth not notably enlarged .............................................. 39
39 Mesosoma dorsum lacking standing pilosity .............................................................. 40
- Mesosoma dorsum with standing pilosity .................................................................. 41
40 Petiole flattened, plate-like, and without a conspicuous, dorsally protruding scale (petiole often overhung by the succeeding abdominal segment); dorsal face of propodeum much shorter than the declivitous (posterior) face ............................ Tapinoma Foerster
- Petiole with a well developed, dorsally protruding scale; dorsal face of propodeum subequal in length to declivitous face .............................................. Linepithema Mayr
41 In profile mesosoma dorsum without an impressed metanotal groove, the promesonotum and propodeum forming a continuous surface; workers variable in size within a colony ........................................................................................................... Liometopum Mayr
- In profile mesosoma dorsum interrupted by a well marked metanotal groove; workers showing little intra-colony size variation .................................................................... 42
42 Petiole lacking an erect scale; side of mesosoma with conspicuous microreticulate sculpture; dark brown-black, with contrastingly paler tarsi .......... Technomyrmex Mayr
- Petiole with well developed erect scale; side of mesosoma without conspicuous microreticulate sculpture; varying in color from yellowish-orange to dark brown, but without contrastingly paler tarsi ............................................................ Forelius Emery
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Source | http://antbase.org/ants/publications/21008/21008.pdf |
Tongue sticks out elastically: ants
The tongue of ants protracts using elastic mechanisms.
"The mouthparts are very important tools for almost any task performed by ants. In particular, the labiomaxillary complex is essential for food intake. In the present study we investigated the anatomical design of the labiomaxillary complex in various ant species, focusing on movement mechanisms. Six labial and six maxillary muscles with different functions control the several joints and ensure the proper performance of the labiomaxillary complex…the labial and maxillary muscles feature rather slow than fast muscle characteristics and do not seem to be specialized for specific tasks. Since glossa [tongue] protractor muscles are absent, the protraction of the glossa, the distal end of the labium, is a nonmuscular movement. By histological measurements of hemolymph volumes we could exclude a pressure-driven mechanism. Additional experiments showed that, upon relaxation of the glossa retractor muscles, the glossa protracts elastically. This elastic mechanism possibly sets an upper limit to licking frequency, thus influencing food intake rates and ultimately foraging behavior. In contrast to many other elastic mechanisms among arthropods, glossa protraction in ants is based on a mechanism where elasticity works as an actual antagonist to muscles. We compared the design of the labiomaxillary complex of ants with that of the honeybee and suggest an elastic mechanism for glossa protraction in honeybees as well." (Paul et al. 2002:39)
Learn more about this functional adaptation.
- Paul J; Roces F, Hölldobler. 2002. How do ants stick out their tongues?. Journal of Morphology. 254(1): 39-52.
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Rights holder/Author | (c) 2008-2009 The Biomimicry Institute |
Source | http://www.asknature.org/strategy/c4f12597290dea5bb1fe891efbb1dfe9 |
A few genera are divided into parts, reflecting distinct characters sets outlined in Table 1.
1. Two distinct, long, narrow spines or lobes present on apical portion of abdominal sternum IX (Fig. 3a) or, if absent, then mandibles extremely elongated, distinctly longer than head, and volsella massive, claw-shaped, directed dorsally. Pygostyles absent........................................................... Cerapachyinae
- Spines or lobes absent on apical portion of abdominal sternum IX or the apical portion bilobed, with each lobe very wide (Fig. 3b). Mandibles not elongated, distinctly shorter than head. Volsella moderate, not claw-shaped, not directed dorsally. Pygostyles present or absent......................................................2
2. Abdominal segment III much smaller than segment IV in lateral view (Fig. 3c)....................................3
- Abdominal segment III nearly as large as segment IV in lateral view (Fig. 3d)......................................4
3. Hind tibia with two spurs (Fig. 3e)......................................................................... Pseudomyrmecinae
- Hind tibia with one spur or without spurs (Fig. 3f) ............................................................. Myrmicinae
4. Anal region of hind wing vestigial. Oblique mesopleural furrow reaching pronotum close to its posteroventral corner (Fig. 4a)...................................................................................................... Proceratiinae
- Anal region of hind wing well developed. Oblique mesopleural furrow not reaching pronotum, its anterior termination well separated from the pronotum (Fig. 1a)..................................................................5
5. Petiole (abdominal segment II) broadly and dorsally attached to abdominal segment III; dorsal constriction between petiole and abdominal segment III very shallow or indistinct in lateral view (Fig. 4b......... ........................................................................................................................................ Amblyoponinae
- Petiole (abdominal segment II) narrowly and ventrally attached to abdominal segment III; dorsal constriction between petiole and abdominal segment III deep in lateral view (Fig. 6a)...6
6. Scuto-scutellar suture usually longitudinally sculptured. Forewing clearly with cross vein 2rs-m (Fig. 1b); if vein weak then at least with vestigial branches on Radial sector and Media. Scape short, not reaching posterior margin of head in full-face view (Fig. 5c). Constriction between abdominal segments III and IV present in some cases.............................................................................................. Ponerinae
- Scuto-scutellar suture not longitudinally sculptured. Forewing usually without any trace of cross vein 2rs-m (Fig. 4c). Scape short (Fig. 4d) or long (Fig. 2a). Constriction between abdominal segments III and IV absent...........................................................................................................................................7
7. Many minute, serrate teeth present on masticatory margin of mandible (Fig. 4d), or, if teeth absent, then scape not reaching posterior margin of head in full-face view........................................ Dolichoderinae
- Several larger teeth present on masticatory margin of mandible (Fig. 2a). Scape long, distinctly exceeding posterior margin of head in full-face view (Fig. 2a)........................................................ Formicinae
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Source | http://www.mapress.com/zootaxa/2007f/zt01654p040.pdf |
Communication is resilient: Temnothorax ants
Communication behaviors in Temnothorax ants are resilient because they have evolved as anytime algorithms.
"Tandem runs are a form of recruitment in ants. During a tandem run, a single leader teaches one follower the route to important resources such as sources of food or better nest sites. In the present study, we investigate what tandem leaders and followers do, in the context of nest emigration, if their partner goes missing. Our experiments involved removing either leaders or followers at set points during tandem runs. Former leaders first stand still and wait for their missing follower but then most often proceed alone to the new nest site. By contrast, former followers often first engage in a Brownian search, for almost exactly the time that their former leader should have waited for them, and then former followers switch to a superdiffusive search. In this way, former followers first search their immediate neighbourhood for their lost leader before becoming ever more wide ranging so that in the absence of their former leader they can often find the new nest, re-encounter the old one or meet a new leader. We also show that followers gain useful information even from incomplete tandem runs. These observations point to the important principle that sophisticated communication behaviours may have evolved as anytime algorithms, i.e. procedures that are beneficial even if they do not run to completion." (Franks et al. 2010:1697)
Learn more about this functional adaptation.
- Franks NR; Richardson TO; Keir S; Inge SJ; Bartumeus F; Sendova-Franks AB. 2010. Ant search strategies after interrupted tandem runs. Journal of Experimental Biology. 213: 1697-1708.
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Rights holder/Author | (c) 2008-2009 The Biomimicry Institute |
Source | http://www.asknature.org/strategy/7e00dd34546f903c5860d306e1defead |
Ants are found just about every habitat on land except the very coldest. All ant species need sheltered places to nest and take care of their offspring. Most species nest underground, but some nest in trees. Some very small ant species can make nests inside acorns and other small hiding places.
Adult ants can live in drier conditions than many other invertebrates, but ant eggs and young need humid conditions to survive.
Habitat Regions: temperate ; tropical ; polar ; terrestrial
Terrestrial Biomes: tundra ; taiga ; desert or dune ; savanna or grassland ; chaparral ; forest ; rainforest ; scrub forest ; mountains
Wetlands: marsh ; swamp ; bog
Other Habitat Features: urban ; suburban ; agricultural
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | ©1995-2012, The Regents of the University of Michigan and its licensors |
Source | http://www.biokids.umich.edu/critters/Formicidae/ |
Colonies distribute food after famine: Temnothorax ants
Colonies of Temnothorax ants distribute food effectively and safely after famine using multiple techniques, including food dilution, strategic food location within community, and living 'silos'.
"Resource distribution is fundamental to social organization, but it poses a dilemma. How to facilitate the spread of useful resources but restrict harmful substances? This dilemma reaches a zenith in famine relief. Survival depends on distributing food fast but that could increase vulnerability to poisons. We tested how Temnothorax albipennis ants solve this dilemma in the distribution of honey solution after 48 h of starvation in four colonies with individually marked workers. We constructed the complete network of liquid food transmission (trophallaxis) between individuals. Within the first 30 min of famine relief, 95% of the workers received food and the distribution rate was an order of magnitude faster compared to the controls. We tested the assumptions of a simple analytical model that best fitted our data. Good mixing during famine relief was facilitated by the movement of internal workers away from the brood pile and the movement of foragers with food away from the nest entrance. This is intriguing because T. albipennis workers have spatial fidelity zones and in the controls internal and external workers were segregated. We discovered that colony vulnerability to poisons during famine relief might be mitigated by: (1) the dilution of food from the same source through mixing, (2) the concentration of food in workers positioned midway between the colony centre and its periphery and (3) the existence of living 'silos'. The latter are expendable foragers, who stay inside the nest and store food during famine relief, thus acting as potential disposable testers for food toxicity." (Sendova-Franks et al. 2010:473)
Learn more about this functional adaptation.
- Sendova-Franks AB; Hayward RK; Wulf B; Klimek T; James R; Planqué R; Britton NF; Franks NR. 2010. Emergency networking: famine relief in ant colonies. Animal Behaviour. 79(2): 473-485.
- Viegas J. 2010. Poison-taster ants help save colonies. Discovery News [Internet],
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Rights holder/Author | (c) 2008-2009 The Biomimicry Institute |
Source | http://www.asknature.org/strategy/9112601d62f1d8a40474358f623cc519 |
Most ants are females. In fact only the princes are males. Nearing mating season the queen produces large amounts of male unfertilized egg to cope up with the short supply of males and ensure successful breeding. During mating seaon a number of ants swarm outside their colony to take part or root for for the "marriage fligt" wherein prince and princess ants take off from their colony , mate in the air and fly off to a new place to start a new colony. The only role of male ants is to mate with the queen and they die alone shortly after mating.
- http://researchnews.osu.edu/archive/harvant.html
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Rights holder/Author | Owel, Owel |
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Collaborating for group decisions: honeybees
Honeybees collaborate when foraging, selecting a new hive through knowledge sharing.
"Researchers at the Univ. of Illinois at Urbana-Champaign, led by principal researcher Feniosky Pena-Mora, are looking at ways to improve human collaboration during disaster relief efforts. They are attempting to draw inspiration from the collaboration patterns that honeybees use in their decision-making process when selecting a new hive or foraging, ants' behavior when they are under threat, and how infectious diseases spread among human populations. The team includes biological, computer, and social scientists, and civil engineers. The team believes that civil engineers should be a fourth group of first-responders at disaster relief efforts involving critical physical infrastructures. The researchers will develop ad hoc communication networks to spread critical information among first responders, similar to how a virus spreads. Models of collaboration based on study of ants and bees may be useful in understanding the basic principles and best practices when developing strategies to coordinate knowledge sharing in chaotic social settings." (Courtesy of the Biomimicry Guild)
Learn more about this functional adaptation.
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Rights holder/Author | (c) 2008-2009 The Biomimicry Institute |
Source | http://www.asknature.org/strategy/df8649b6cae0b9e739df42001c5073ea |