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Pheidole
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Pheidole is currently the most species rich genus of ants in the world, with many species still awaiting description (Moreau, 2008).
With a worldwide distribution, the "hyperdiverse" myrmicine genus Pheidole is unsurpassed for number of species in a single ant genus (Wilson, 2003). Pheidole presently comprises more than 9.5 percent of the entire known world ant fauna with over 1,100 species described worldwide (Bolton et al., 2007). The 600+ described species of Pheidole in the New World were recently the subject of a major revision by E. O. Wilson (2003) that included species descriptions and detailed morphological drawings of each species.
Ants in the genus Pheidole possess a dimorphic worker caste that is comprised of a minor worker subcaste and major worker subcaste, with these big-headed major workers sometimes referred to as soldiers. All known species of Pheidole are dimorphic - except six species of workerless social parasites and at least eight species possess an unusually large super major subcaste in addition to the typical minor and major subcastes (trimorphic worker caste), with minor workers performing most of the tasks within the nest and foraging, and large-headed majors specializing on colony defense and/or food processing. A large number of Pheidole major workers are also known to be involved in the milling of seeds harvested by the minor and major worker caste, and these seeds are often stored in granaries within the ant nest. The evolution of worker polymorphism in ants has been hypothesized to be associated with a dietary change (Wilson, 1984; Hölldobler & Wilson, 1990; Ferster et al., 2006; Powell & Franks, 2006).
Additionally ants in Pheidole exhibit reduction of the sting in both the major and minor caste without an increase in defensive secretions. Defense of the colony and food sources are executed by cooperative fighting, instead of a “sting”. Group retrieval of prey items is often accomplished by “spread-eagling” the prey or intruder.
The earliest confirmed fossil specimens of Pheidole are found in the Florissant shales of Colorado, which is late Eocene, ~34 million years ago (Ma) in age (Carpenter, 1930).
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Rights holder/Author | Corrie Moreau, Corrie Moreau |
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GenusPheidole HNS Westwood, 1841
Pheidole HNS Westwood, 1841:87.
Type-species: Atta providens Sykes HNS , 1835.
Figs. 76-80.
Workers. Markedly dimorphic with large broad headed workers contrasting with smaller workers with narrow oval heads. Mandibles broad with very rounded exterior margins and teeth reduced to 2 or 4 in major workers, multidentate in minor workers. Mesopropodeal suture very deep, mesonotum often prominently raised. Antennae terminating in distinct three segmented club as long as or longer than rest of funiculus.
Figs. 72-75. Stenamma westwoodii Westwood HNS . - 72: head of worker in dorsal view; 73: queen in profile; 74: worker in profile; 75: male in profile. Scale: 1 mm.
Queen . Head rectangular with well developed eyes and ocelli. Gaster more or less truncated at base.
Male. Antennal scape very short; first funicular segment swollen. Eyes and ocelli enormous, the latter developed on a prominence.
This genus includes many hundreds of similar species occurring throughout the tropics and subtropics with one European species P. pallidula (Nylander) HNS . Several species may be introduced with imported fruit or on plant material; the commonest cosmopolitan species is P. megacephala (Fabricius) HNS and this species and others of the genus have been recorded from time to time from heated premises in England and Denmark.
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Rights holder/Author | No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation. |
Source | http://treatment.plazi.org/id/430BB1C9C044A444B1B39347A2D17788 |
sp. alw-06.
Central (ALWC).
- Wild, A. L. (2007): A catalogue of the ants of Paraguay (Hymenoptera: Formicidae). Zootaxa 1622, 1-55: 35-35, URL:http://www.antbase.org/ants/publications/21367/21367.pdf
License | Public Domain |
Rights holder/Author | No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation. |
Source | http://treatment.plazi.org/id/50E392047872B765CF24E8AFA3E70B74 |
Amambay, Canindeyú (ALWC).
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Pheidole (Pheidole sp.) preys on:
various
toad carrion
Oxysarcodexia ochripyga
carcass
Diptera
Blaesoxipha plinthopyga
Cochyliomyia macellaria
Musca domestica
Lepus californicus
Based on studies in:
USA: North Carolina (Forest, Plant substrate)
Costa Rica: Guanacaste (Carrion substrate)
USA: New Mexico, Aden Crater (Carrion substrate)
USA: Texas, Franklin Mtns (Carrion substrate)
This list may not be complete but is based on published studies.
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Rights holder/Author | Cynthia Sims Parr, Joel Sachs, SPIRE |
Source | http://spire.umbc.edu/fwc/ |
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Pheidole HNS Westwood
Small ants with the worker strongly dimorphic, the two forms being designated as the worker and soldier. In a few species these phases are connected by intermediates(mediae).
Soldier with very large head, subrectangular or subcordate, more or less deeply notched or excised behind and with a distinct occipital furrow, on each side of which the occipital region is convex. Clypeus short, depressed, carinate or ecarinate but not elevated in the middle, the anterior border entire or notched in the middle, the posterior border extending back between the frontal carinae, which vary in length, being short in some species and in others greatly prolonged backward and forming the inner borders of more or less distinct scrobes for the antennae. Frontal area usually distinct, deeply impressed. Mandibles large, convex, usually with two apical and two basal teeth, separated by a toothless diastema. Antennae 12-jointed; the funiculus with long first joint; joints 2 to 8 small and narrow; the three terminal joints forming a well-developed club. Thorax small, usually with distinct promesonotal and mesoepinotal sutures and pronounced mesoepinotal constriction; the pro- and mesonotum raised, more or less convex, the humeri sometimes prominent, the mesonotum often with a transverse welt or torus; the metanotum sometimes represented by a distinct sclerite; the epinotum armed with spines or teeth, in profile with distinct basal and declivous outline. Petiole small and narrow, pedunculate anteriorly, the node posterior, compressed anteroposteriorly, its superior border sometimes emarginate, the ventral surface unarmed. Postpetiole broader than the petiole, convex and rounded above, contracted behind, the sides often produced as angles or conules, more rarely as spines. Gaster rather small, broadly elliptical or subcircular. Femora more or less thickened in the middle; middle and hind tibiae without spurs; tarsal claws simple.
Worker smaller than the soldier but very similar in the structure of the thorax, pedicel, and gaster; the head, however, much smaller, not grooved nor deeply excised posteriorly; the antennae longer; the mandibles less convex, with evenly denticulate apical borders. The pro- and mesonotum are proportionally less convex, and the petiole and postpetiole are more slender.
Female resembling the soldier but larger; the head proportionally smaller and shorter, usually not longer than broad and not broader than the thorax; the occiput only broadly and feebly excised. Thorax broad and massive; the mesonotum flat, overarching the pronotum in front. Epinotal spines shorter and stouter; petiole and postpetiole more massive; gaster much larger and more elongate than in the soldier. Wings long, with a discoidal cell, two closed cubital cells, and an open radial cell.
Male decidedly smaller and more slender than the female, the head small, with large, convex eyes and ocelli; mandibles small but dentate. Clypeus longer than in the soldier. Antennae 13-jointed; the scapes very short, scarcely longer than the second Funicular joint, first joint sub globular. Thorax broad; the mesonotum flattened, without Mayrian furrows, anteriorly overarching the small pronotum; epinotum unarmed. Petiole and postpetiole slender, with low nodes. Gaster slender, elongate. Genital appendages small. Cerci present. Legs long and slender. Wing venation as in the female.
The species of this very large and difficult genus are distributed over the tropics and warmer temperate areas of both hemispheres (Map 20). In the Nearctic Region the northernmost range is southern New England and Oregon; in the Palearctic, Japan and northern Italy; in the southern hemisphere it reaches Argentina and Tasmania. Emery has divided the genus into a number of subgenera and has rejected a couple of subgenera, Allopheidole HNS and Cardiopheidole, described by Forel and myself. The various groups have been characterized by Emery in a recently published portion of the ' Genera Insectorum' on the Myrmicinae.
Map 20. Distribution of the genus Pheidole HNS .
Nearly all the species of Pheidole HNS nest in the ground, either under stones and logs or in crater or small mound nests. Many species feed exclusively on insects and often have a peculiar fecal odor precisely like that of the Dorylinae, which also have an insect diet; but many species are harvesters and store the chambers of their nests with the seeds of small herbaceous plants. This is especially true of the desert species of Pheidole HNS . In some species in Australia and the southern United States, the soldiers take on the function of repletes and store in their crops sweet liquid for the use of the colony during periods of food and water scarcity. One species, Pheidole megacephala HNS , has been carried to all parts of the tropics and has become a great pest in and about dwellings and plantations as it assiduously cultivates coccids on many economic plants and ruthlessly destroys and replaces the native ant-faunas. This has been observed in the Madeira Islands, Hawaii, Australia, and the West Indies. In all probability P. megacephala HNS is of Ethiopian or Malagasy origin, as it shows a great development of subspecies and varieties in these two regions and nowhere else.
License | Public Domain |
Rights holder/Author | No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation. |
Source | http://treatment.plazi.org/id/2914DE6B3E028526767DE4211B6D475D |
Diagnosis of the Pheidole roosevelti-group HNS
The species of the Pheidole roosevelti-group HNS can be distinguished from those of other congeners by the following combination of characters.
1. Mesonotum of major and minor workers with a posteriorly projecting process.
2. Mesonotal declivity of major and minor workers concave.
3. Propodeal spines elongate and either simple or modified apically into an angulate point or bifurcation.
4. Pronotal spines or projections absent.
5. Hypostoma of major worker with a well developed median tooth, one pair of inner teeth, and one pair of outer teeth.
6. Palp formula 2:2 in major and minor workers.
7. Petiole peduncle elongate.
8. Occipital carina absent dorsally.
The recent discovery of five new species and an examination of additional material for the two previously described species requires a broadening of the original diagnosis outlined by Mann (1921) for the P. roosevelti-group HNS . Pheidole simplispinosa HNS sp. n. , with its simple propodeal spines, truncated mesonotal process and unmargined head, is both the most aberrant of the group and the primary cause for broadening the definition. However, compared to other Pheidole HNS of the Pacific region, P. simplispinosa HNS is more similar in morphology to the other members of the P. roosevelti-group HNS than to any other species examined.
Synopsis of Pheidole roosevelti-group HNS
P. bula HNS sp. n.
P. colaensis Mann HNS , 1921
P. furcata HNS sp. n.
P. pegasus HNS sp. n.
P. roosevelti Mann HNS , 1921
P. simplispinosa HNS sp. n.
P. uncagena HNS sp. n.
Key to species
The following keys diagnose the known minor workers, major workers, and queens of each species included in the Pheidole roosevelti-group HNS with the exception of the queen caste of Pheidole uncagena HNS sp. n, which is unknown.
Minors
1 Propodeal spines simple, evenly tapering to a single straight acuminate point without becoming bifurcate or angulate apically (Figs. 21b, 48); mesonotal process truncated into a blunt process without lamellate or distinct posterior margin (Figs. 21a, 48); head as broad as long, scapes shorter, metafemur shorter (CI 0.98-1.03, SL 0.77-0.85, FL 0.80-0.91, n = 10).................................................... P simplispinosa HNS , sp. n.
- Propodeal spines modified apically with bifurcate or angulate tip, but never evenly tapering to a single straight acuminate point (Figs. 22b, 33, 36, 39, 42, 45, 51); mesonotal process with lamellate or acute posterior margin (Figs. 22a, 33, 36, 39, 42, 51); head longer than broad, scapes longer, metafemur longer (CI 0.87-0.96, SL 0.97-1.66, n = 51)................................................................................................................2
2 Head, in full face view, smooth and shining above level of eyes (Figs. 35, 41, 50); promesonotum, in dorsal view, smooth and shining (Figs. 37, 43, 52) .......................................................................................... 3
- Head, in full face view, rugose to rugoreticulate above level of eyes (Figs. 32, 38, 44); promesonotum, in dorsal view, transversely rugose to rugoreticulate (Figs. 34, 40, 46) .......................................................... 5
3 Head venter, in profile, with genal carinae modified into elevated flanges (Figs. 25, 51); mesonotal process, in dorsal view, strongly attenuated (Figs. 24, 52); head, in full face view, oval shaped without posterolateral corners forming obtuse angles (Fig. 50); propodeal spines with dorsal edge approximately as long as anterior edge (PSI 0.87-1.13, n = 8); color of petiole, postpetiole and gaster distinctly lighter than mesosoma and head....................................................................................................... P. uncagena HNS , sp. n.
- Head venter, in profile, with genal carinae either indistinct (Fig. 26b) or forming a collar around foramen (Fig. 27b), but never modified into elevated flanges; mesonotal process, in dorsal view, broad (Figs. 23, 37, 43); head, in full face view, subquadrate with posterolateral corners forming obtuse angles (Figs. 35, 41); propodeal spines with dorsal edge either distinctly shorter than anterior edge (PSI 0.29-0.77, n = 8) or distinctly longer than anterior edge (PSI 1.46-1.71, n = 9); color of petiole, postpetiole and gaster either lighter or same as mesosoma and head........................................................................................................ 4
4 Propodeal spines with dorsal edge distinctly longer than anterior edge (PSI 1.46-1.71, n = 9) (Figs. 13, 42); posterior of head strongly pinched dorsoventrally (Figs. 27a, 42), appearing flattened in profile and shield-like in full face view; color of petiole, postpetiole and gaster distinctly lighter than mesosoma and head; scapes longer, metafemur longer (SL 1.21-1.27, FL 1.58-1.66, n = 9)................. P. pegasus HNS , sp. n.
- Propodeal spines with dorsal edge distinctly shorter than anterior edge (PSI 0.29-0.77, n = 8) (Figs. 14, 36); posterior of head weakly pinched dorsoventrally (Figs. 26a, 36), but not appearing flattened in profile or a shield-like in full face view; color of petiole, postpetiole and gaster same as mesosoma and head; scapes shorter, metafemur shorter (SL 0.99-1.06, FL 1.12-1.23, n = 8).................................. P. colaensis HNS
5 Head venter smooth and shining (Fig. 39); in profile, genal carinae inconspicuous (Figs. 26b, 39)............ ........................................................................................................................................... P. furcata HNS , sp. n.
- Head venter sculptured (Figs. 33, 45); strongly produced genal carinae present (Figs. 28b, 33, 45).........6
6 Head, in full face view, with strongly branching network of longitudinal and transverse rugae (Fig. 44); spaces between head rugoreticulum strongly foveolate; pronotum, in dorsal view, rugoreticulate (Fig. 46); mesonotal process, in dorsal view, broadly lamellate and with a medially excised posterior margin (Fig. 46)............................................................................................................................................. P. roosevelti HNS
- Head, in full face view, with discontinuous longitudinal rugae that branch occasionally, but become rugoreticulate only on posterolateral corners of head (Fig. 32); spaces between head rugae smooth and shining; pronotum, in dorsal view, shining with transverse rugae (Fig. 34); mesonotal process, in dorsal view, narrowly lamellate with flat to weakly concave posterior margin (Fig. 34)........................... P bula HNS , sp. n.
Majors
1 Mesonotal process, in profile, truncated into a blunt angle without lamellate or acute posterior margin (Figs. 8a, 69); propodeal spines simple, evenly tapering to a single straight acuminate point without becoming bifurcate or angulate apically (Figs. 8b, 69); posterolateral lobes, in full face view, with distinct transverse rugae extending from median cleft to posterolateral corners (Figs. 11, 68); scapes short (SL 0.73-0.84, n = 9)...................................................................................................... P. simplispinosa HNS , sp. n.
- Mesonotal process, in profile, with acute posterior angle or lamella (Figs. 9a, 10a, 54, 57, 60, 63, 66, 72); propodeal spines usually modified apically with bifurcate or angulate tip (Figs. 9b, 10b, 54, 57, 60, 63, 66, 72); posterolateral lobes, in full face view, variably sculptured but never with distinct transverse rugae extending from median cleft to posterolateral corners (Figs. 53, 56, 59, 62, 65, 71); scapes of variable length (SL 0.90-1.19, n = 35).....................................................................................................................2
2 Posterolateral lobes, in full face view, smooth and shining without rugae or carinae (Figs. 12a, 56); median ocellus present and well developed (Figs. 12b, 56); intercarinular spaces on head smooth and shining; postpetiole with anterior face and dorsum smooth and shining without rugulae; gaster with basal portion of first tergite smooth and shining (Fig. 58) ................................................................. P. colaensis HNS
- Posterolateral lobes, in full face view, sculptured with rugae or carina (Figs. 53, 59, 62, 65, 68, 71); median ocellus present or absent; intercarinular spaces on head smooth and shining to foveolate; postpetiole with anterior face and dorsum smooth and shining to rugulose-foveolate; gaster with basal portion of first tergite smooth and shining to densely sculptured ................................................................................ 3
3 Posterolateral lobes, in full face view, rugoreticulate, such that longitudinal rugae are intersected by transverse rugae (Figs. 53, 59, 65); pronotum, in dorsal view, rugoreticulate, such that transverse rugae are often intersected by longitudinal rugae (Figs. 55, 61, 67); sides of petiole, in posterior view, subparallel without laterally projecting processes ......................................................................................................... 4
- Posterolateral lobes, in full face view, carinate, such that longitudinal carinae are not intersected by transverse carinae (Figs. 62, 71); pronotum, in dorsal view, rugose, such that transverse rugae not intersected by longitudinal rugae (Figs. 64, 73); sides of petiole, in posterior view, emarginated with laterally projecting processes................................................................................................................................................ 6
4 Posterolateral lobes, in full face view, with rugoreticulum terminating before obtaining posterior margin (Fig. 59); in dorsal view, length of median basigastral sculpturing immediately posterior to postpetiole attachment longer than length of postpetiole (Figs. 15, 61); head shorter (HL 1.95-2.04, n = 7)................ ........................................................................................................................................... P. furcata HNS , sp. n.
- Posterolateral lobes, in full face view, with rugoreticulum obtaining posterior margin (Figs. 53, 65); in dorsal view, length of median basigastral sculpturing immediately posterior to postpetiole attachment shorter than length of postpetiole (Figs. 55, 67); head longer (HL 2.06-2.38, n = 13)...............................5
5 Head, in full face view, with intercarinular spaces densely and distinctly foveolate (Fig. 65); postpetiolar dorsum, in dorsal view, rugulose with foveolate interspaces; scapes shorter relative to head (SI 0.41-0.46, n =8)......................................................................................................................................... P. roosevelti HNS
- Head, in full face view, with intercarinular spaces smooth and shining to weakly impressed, but never densely nor distinctly foveolate (Fig. 53); postpetiolar dorsum, in dorsal view, smooth and shining; scapes longer relative to head (SI 0.48-0.53, n = 5).......................................................................... P. bula HNS , sp. n.
6 Propodeal spines, in profile, with dorsal edge as long as or longer than anterior edge (Figs. 17, 63); mesonotal process, in dorsal view, broad basally (Figs. 19, 64); petiole with posterior face smooth and shining; head wider, metafemur longer, scapes longer (HW 2.20-2.35, FL 1.59-1.66, SL 1.15-1.19, n = 3) P. pegasus HNS , sp. n.
- Propodeal spines, in profile, with dorsal edge distinctly shorter than anterior edge (Figs. 18, 72); mesonotal process, in dorsal view, strongly attenuated basally (Fig. 20, 73); petiole with posterior face rugoreticulate; head narrower, metafemur shorter, scapes shorter (HW 2.05-2.12, FL 1.51-1.57, SL 1.09-1.12, n = 5).................................................................................................................................... P. uncagena HNS , sp. n.
Queens
1 Propodeal spines simple and straight, evenly tapering to a single acuminate point without becoming bifurcate or angulate apically (Figs. 29, 90); scapes short (SL 0.87, FL n = 1).............. P simplispinosa HNS , sp. n.
- Propodeal spines modified apically with bifurcate or angulate tip, but never evenly tapering to a single straight acuminate point (Figs. 30, 31, 75, 78. 81. 84. 87); scapes long (SL 0.97-1.24, n = 15)...............2
2 Mesonotum, in profile, lower than pronotum (Figs. 31, 75, 78, 81); pronotum, in dorsal view, largely visible(Figs. 76, 79, 82); sides of head, in full face view, subparallel or weakly diverging posteriorly (Figs. 74, 77, 80); head narrow (HW 1.12-1.35, n = 8)........................................................................................3
- Mesonotum, in profile, subequal in height to pronotum (Figs. 30, 84, 87), pronotum, in profile, largely concealed by mesonotum (Figs. 85, 88); sides of head, in full face view, strongly diverging posteriorly (Figs. 83, 86); head broad (HW 1.55-1.95, n = 7)......................................................................................5
3 Head venter densely sculptured; anterior face of postpetiole with regular longitudinal rugulae.................. ................................................................................................................................................ P. bula HNS , sp. n.
- Head venter smooth and shining; postpetiole with anterior face either smooth and shining or with weak irregular sculpture, but never with regular longitudinal rugulae ................................................................. 4
4 Head with posterolateral corners smooth and shining (Fig. 77); petiolar node, in posterior view, concave; postpetiolar dorsum smooth and shining; in dorsal view, length of median sculpturing immediately posterior to postpetiole attachment shorter than length of postpetiole (Fig. 16); head wider and longer (HW 1.29-1.35, HL 1.27-1.30, n = 3)............................................................................................... P. colaensis HNS
- Head with posterolateral corners rugoreticulate and with intercarinular spaces foveolate (Figs. 80); petiolar node, in posterior view, flat; postpetiolar dorsum transversely striate; in dorsal view, length of median sculpturing immediately posterior to postpetiole attachment equal to or longer than length of postpetiole (Fig. 15); head narrower and shorter (HW 1.12-1.18, HL 1.14-1.17, n = 3)................... P. furcata HNS , sp. n.
5 Head, in full face view, with posterior portion rugoreticulate such that irregular longitudinal rugae are often intersected by irregular transverse rugae (Fig. 86); ground sculpture between eyes and frontal carinae densely and distinctly foveolate; head narrower and shorter (HW 1.55-1.70, HL 1.37-1.52, n = 6).... .................................................................................................................................................. P. roosevelti HNS
- Head, in full face view, with posterior portion longitudinally carinate such that longitudinal carinae may occasionally branch, but are never intersected by transverse carinae or rugae (Fig. 83); ground sculpture between eyes and frontal carinae smooth and shining; head wider and longer (HW 1.96, HL 1.73, n = 1).... ......................................................................................................................................... P. pegasus HNS , sp. n.
- Sarnat, E. M. (2008): A taxonomic revision of the Pheidole roosevelti-group (Hymenoptera: Formicidae) in Fiji. Zootaxa 1767, 1-36: 7-11, URL:http://hol.osu.edu/reference-full.html?id=21683
License | Public Domain |
Rights holder/Author | No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation. |
Source | http://treatment.plazi.org/id/49941D92F1F89E3B2BE9BF18A864CB9F |
Alto Paraná (ALWC, BMNH).
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Barcode of Life Data Systems (BOLDS) Stats
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