Strumigenys, Smith, 1860

Booher, Douglas B., 2021, The ant genus Strumigenys Smith, 1860 (Hymenoptera: Formicidae) in western North America North of Mexico, Zootaxa 5061 (2), pp. 201-248 : 206

publication ID

https://doi.org/10.11646/zootaxa.5061.2.1

publication LSID

lsid:zoobank.org:pub:D3925450-125B-4E92-8988-64ED1C544672

DOI

https://doi.org/10.5281/zenodo.5717495

persistent identifier

https://treatment.plazi.org/id/DA6387B5-C72D-0D27-FF14-FF04FA31F84D

treatment provided by

Plazi

scientific name

Strumigenys
status

 

Key to western nearctic Strumigenys species (workers and queens)

Illustrations by C. Dandridge

1 Mandibles with at least some teeth interlocking or overlapping in the first half of mandible when fully closed ( Fig. 2A View FIGURE 2 ); MI <22 ................................................................................................. 2 - Mandibles with interlocking teeth limited to the apical half of mandible ( Fig. 2 View FIGURE 2 AA); MI ≥ 25 (see also third choice below). 30 - Mandibles with an elongate flat-topped basal lamella of the mandible followed by a second flat topped elongate lamella that extends to the middle of masticatory margin ( Fig. 2 View FIGURE 2 AAA); MI ≥ 27–33...................................................................................................... alberti Forel 1893 (a single specimen collected, NV) 2 Four to six erect setae radiate from the medial anterior dorsum of clypeus and spread out like ribs of a fan, most easily observed when viewed from apex of clypeus ( Fig. 3A View FIGURE 3 )............................................................... 3 - Erect setae are not present on anterior dorsum of clypeus, or if present, these setae are not organized like ribs of a fan ( Fig. 3 View FIGURE 3 AA)............................................................................................... 4 3 Fan shaped clypeal setae expanded and bulbous at tips ( Fig. 4A View FIGURE 4 ), curving posteriorly in lateral view.............................................................................. ornata Mayr, 1887 (OK, TX, and many eastern states) - Fan shaped clypeal setae are apically acute to slightly expanded ( Fig. 4 View FIGURE 4 AA) and do not curve posteriorly in lateral view........................................................ dietrichi Smith, 1931 (KS, OK, TX, and many eastern states) 4 Fringe of setae on margins of clypeus either absent or minute and appressed but never projecting outward away from margin ( Fig. 5A View FIGURE 5 )............................................................................................ 5 - Fringe of setae on margins of clypeus present and project outward from margin, these setae may be of various shapes from long fine and apically acute to spoon shaped ( Fig. 5 View FIGURE 5 AA, AAA)..................................................... 6 5 Mandible with transverse carinae on dorsal surface of mandible just anterior of clypeal margin ( Fig. 6A View FIGURE 6 ) (Cosmopolitan tramp species).................................. membranifera Emery, 1869 (AZ, CA, TX, and several southeastern states) - Mandible without transverse carinae on dorsal surface of mandible just anterior of clypeal margin ( Fig. 6 View FIGURE 6 AA)................................................................................... superstes Booher & Uhey 2020 (AZ) 6 Setae on margins and dorsum of clypeus consist of only apically acute, elongate, simple fine setae that may be coarse, straight, curved, or irregularly flexuous but never expanded ( Fig. 7A View FIGURE 7 )................................................... 7 - Setae on either clypeal margins or dorsum are expanded or flattened ( Fig. 7 View FIGURE 7 AA).................................. 12 7 In dorsal view, spongiform appendages absent on petiolar and postpetiolar nodes, and are replaced by smooth cuticular lamellae on lateral and posterior borders of nodes ( Fig. 8A View FIGURE 8 )........................................... subtilis sp. nov. (CA) - In dorsal view, spongiform appendages large and apparent as white processes on lateral and posterior borders of petiolar node and encircling exposed disc of postpetiole ( Fig. 8 View FIGURE 8 AA)........................................................ 8 8 Clypeus in lateral view with a broad conspicuous peripheral groove along free margins ( Fig. 9A View FIGURE 9 )...................... 9 - Clypeus in lateral view without a peripheral groove ( Fig. 9 View FIGURE 9 AA)................................................ 11 9 Basalmost tooth not following a large diastemmic gap, overlapping when mandible closed and less than half the length of the following tooth ( Fig. 10A View FIGURE 10 ). Setae on margins and dorsum of clypeus are coarse, straight or evenly and shallowly curved along their entire length, extending well past margin ( Fig. 10B View FIGURE 10 )..................................................... 10 - Basalmost tooth following a large diastemmic gap, not overlapping when mandible closed and less than half the length of the following tooth ( Fig. 10 View FIGURE 10 AA). Setae on margins and dorsum of clypeus are fine, often curving strongly along apical portion and barely extending past margin ( Fig. 10 View FIGURE 10 BB)............................................... collinsae sp. nov. (CO) 10 Setae on dorsum of clypeus inclined anterior at base and evenly curve so that their apices point upwards or posteriorly ( Fig. 11A View FIGURE 11 ).............................................. laevinasis Smith, 1931 (KS, OK, TX, and many eastern states) - Setae on dorsum of clypeus inclined anterior at base and evenly curve so that their apices point upwards or posteriorly ( Fig. 11B View FIGURE 11 )............................................. brevisetosa Smith, 1935 (KS, OK, TX, and many eastern states) 11 With head in full-face view setae that project from the lateral clypeal margin fine, conspicuously J-shaped and curve posteriorly ( Fig. 12A View FIGURE 12 ).............. pilinasis Forel, 1901 (Note: senior synonym of ohioensis ) (KS, OK, TX, and many eastern states) - With head in full-face view setae that project from the lateral clypeal margin variable in form but not J-shaped and curve or are inclined anteriorly ( Fig. 12 View FIGURE 12 AA)..................................................... reliquia ( Ward, 1988) (CA) 12 The pair of setae positioned nearest the outer mandible insertions ( Fig. 13A View FIGURE 13 ; sometimes on the anterior margin of clypeus) and often those occurring on the lateral margin of clypeus ( Figs. 14A View FIGURE 14 , 13B View FIGURE 13 ) curve posteriorly, with apices directed towards the back of the head and away from mandibles.................................................................... 13 - The pair of setae positioned nearest the outer mandible insertions ( Fig. 13 View FIGURE 13 AA) and those on the lateral margin of clypeus ( Fig. 13 View FIGURE 13 BB) all curve ventrally or towards mandibles, without apices directed posteriorly............................... 14 13 Two or more pairs of setae positioned nearest the outer mandible insertions Fig. 14A View FIGURE 14 ) or on the lateral margin of clypeus curve away from mandibles........................ reflexa Wesson & Wesson, 1939 (KS, TX, and many other eastern states). - One pair of setae positioned nearest the outer mandible insertions ( Fig. 14B View FIGURE 14 ) curve away from mandibles. Those on the lateral margin curve towards the mandibles................. missouriensis Smith, 1931 (possible, many eastern states; may be a complex of species; should also compare with eastern species) 14 Ventral surface of petiolar peduncle with no trace of spongiform tissue ( Fig. 15A View FIGURE 15 )................................................................................... margaritae Forel, 1893 (TX and many other southeastern states) - Ventral surface of petiolar peduncle with obvious lamella of spongiform tissue ( Fig. 15 View FIGURE 15 AA)......................... 15 15 Setae on the posterior half of clypeal dorsum ( Fig. 16A View FIGURE 16 ) with several to many setae that curve and are directed posteriorly or posterolaterally...................................................................................... 16 - Setae on posterior half of clypeal dorsum ( Fig. 16 View FIGURE 16 AA) consisting of anteriorly or anterolaterally directed setae; without posteriorly directed setae.................................................................................. 18 16 Setae on the anterior margin of clypeus ( Fig. 17A View FIGURE 17 ) curve away from midline............. lucky sp. nov. (IA, IL, MN, WI) - Setae on the anterior margin of clypeus ( Fig. 17 View FIGURE 17 AA) curve ventrally or towards midline............................ 17 17 Setae covering dorsum of clypeus short, simple to narrowly expanded, and all curving posteriorly ( Fig. 18A View FIGURE 18 )................................................................................................. macgowni sp. nov. (TX) - Setae on clypeal dorsum expanded, spoon-shaped to scale-like and translucent; those on the anterior portion of clypeus curve anteriorly and posteriormost setae curve posteriorly ( Fig. 18 View FIGURE 18 AA)............................ chiricahua ( Ward, 1988) (AZ) 18 Clypeus with a wide peripheral groove along entire free margin ( Fig. 19A View FIGURE 19 ); maximum width of groove more than 1/3 the maximum length of eye (usually 0.5 times or wider and most easily seen when clypeus is viewed in profile or from anterior apex of clypeus when mandibles are open)....................................................................... 19 - Clypeus without a peripheral groove ( Fig. 19 View FIGURE 19 AA) along margin or, if present, the maximum width of groove is less than 1/3 the maximum length of the eye (usually 0.25 times or less)...................................................... 20 19 Setae on lateral margins of clypeus simple-linear to slightly and evenly expanded along apical portion ( Fig. 20A View FIGURE 20 ), directed anteriorly, and not strongly curving towards the midline; setae on dorsum of clypeus ( Fig. 20B View FIGURE 20 ) similarly shaped but shorter and inclined anteriorly................................... brevisetosa Smith, 1935 (KS, OK, TX, and many eastern states) - Setae on lateral margins of clypeus spatulate ( Fig. 20 View FIGURE 20 AA), directed antero-medially and strongly curving towards the midline; setae on dorsum of clypeus ( Fig. 20 View FIGURE 20 BB) consisting of shorter spatulate setae.......................................................................................... clypeata Roger, 1863 (KS, OK, TX, and many eastern states) 20 Diastemmic gap absent ( Fig. 21A View FIGURE 21 ) or if present it is shorter than the length of the first principle tooth (measured between anterior edge of clypeus to first tooth if apex of basal lamella is hidden by clypeus in full frontal view).................... 21 - Diastemmic gap present ( Fig. 21 View FIGURE 21 AA) and is equal to or longer than the length of the first principle tooth (measured between anterior edge of clypeus to first tooth if apex of basal lamella is hidden by clypeus in full frontal view)................ 24 21 Differentiated pronotal humeral setae absent ( Fig. 22A View FIGURE 22 ), diastema apparent and nearly equal to length of first tooth ( Fig. 22B View FIGURE 22 ).................................................................................. mendezi sp. nov. (AZ) - Pronotal humeral setae present ( Fig. 22 View FIGURE 22 AA) although may be short, extremely fine and difficult to see; diastema obviously shorter than length of first tooth ( Fig. 22 View FIGURE 22 BB)............................................................... 22 22 Pronotal humeral ( Fig. 23A View FIGURE 23 ) setae erect, simple, straight, and stiff (always apparent)............................................................................................ rostrata Emery, 1895 (TX, and many eastern states) - Pronotal humeral setae flagellate ( Fig. 23 View FIGURE 23 AA) and apparent or extremely fine and in some specimens difficult to see...... 23 23 With head in profile clypeus abruptly raised, interrupting the outline of head, with the frontal area impressed and concave ( Fig. 24A View FIGURE 24 )...................................................................... californica ( Brown, 1950) (CA) - With head in profile clypeus not abruptly raised and not interrupting the outline of head, the frontal area continuous with clypeus, straight and not concave ( Fig. 24 View FIGURE 24 AA)........ arizonica ( Ward, 1988) ( USA - TX, AZ, NM; MEX - Sonora, Chihuahua) 24 Differentiated flagellate setae absent on vertex margin of head or at apicoscrobal position of head ( Fig. 25A View FIGURE 25 )........... 25 - Standing flagellate setae present at apicoscrobal position and usually another pair just posterior to the apicoscrobal position along the vertex margin, straddling the midline of head ( Fig. 25 View FIGURE 25 AA)............................................ 27 25 First (basal) tooth about half the length of second tooth and not overlapping opposing tooth in closed position ( Fig. 26A View FIGURE 26 ).................................................................................. moreauviae sp. nov. (NM) - First (basal) two teeth approximately equal in length and overlapping opposed teeth in closed position ( Fig. 26 View FIGURE 26 AA)...... 26 26 At least one pair of setae on the anterior clypeal margin curve strongly away from the midline (sometimes two pairs) ( Fig. 27A View FIGURE 27 ); posterior half of clypeal dorsum with few or no setae.... missouriensis Smith, 1931 (possible, many eastern states; may be a complex of species; should also compare with eastern species) - All setae on the anterior margin of clypeus curve towards the midline ( Fig. 27 View FIGURE 27 AA); posterior half of clypeal dorsum with many setae........................................................... talpa Weber, 1934 (part, specimens from OK) 27 First five teeth alternate in size between similarly large and small teeth, in some individuals basalmost tooth is a small adventitious tooth and in others the first tooth is a large well-developed tooth ( Fig. 28A View FIGURE 28 ).................................. 28 - First and second tooth are nearly equal in size and much larger than third tooth, never alternating in size among the first five basal teeth ( Fig. 28 View FIGURE 28 AA)............................................................................... 29 28 Setae on anterior margin of clypeus ( Fig. 29A View FIGURE 29 ) curve away from midline; setae on anterior dorsum of clypeus curve laterally or posterolaterally ( Fig 29B View FIGURE 29 ); setae are club shaped and opaque.......................... lucky sp. nov. (IA, IL, MN, WI) - Setae on anterior margin of clypeus ( Fig. 29 View FIGURE 29 AA) curve ventrally or towards midline; setae on anterior dorsum of clypeus curve anteriorly or anterolaterally ( Fig 29 View FIGURE 29 BB); setae spoon-shaped and translucent...... ananeotes Longino & Booher, 2019 (UT) 29 One to two pairs of setae on anterior clypeal margin curve away from midline of mandibles ( Fig. 30A View FIGURE 30 ); fewer than five setae are present on lateral margin of clypeus ( Fig. 30B View FIGURE 30 )............. pulchella Emery, 1895 (KS, TX, and many eastern states) - All setae on anterior clypeal margin curve towards the midline ( Fig. 30 View FIGURE 30 AA); more than five setae present on lateral margin of clypeus ( Fig. 30 View FIGURE 30 BB)......................................... talpa Weber, 1934 (OK, TX, and many eastern states) 30 Mandibles short, MI 25–33, outer margins of mandibles convexly bowed ( Fig. 31A View FIGURE 31 )............................... 31 - Mandibles long, MI 50–70, outer margins of mandibles linear ( Fig. 31 View FIGURE 31 AA)....................................... 32 31 Along apical half of mandible basal three teeth triangular ( Fig. 32A View FIGURE 32 ); anterior and lateral margins of the clypeus angulate ( Fig. 32B View FIGURE 32 ); scapes shorter, SI 65–69 ( Fig. 32C View FIGURE 32 )......................... angulata Smith, 1931 (OK and many eastern states) - Along apical half of mandible second tooth following basal tooth bluntly rounded ( Fig. 32 View FIGURE 32 AA); anterior and lateral margins of the clypeus rounded ( Fig. 32 View FIGURE 32 BB); scapes longer, SI 65–69 ( Fig. 32 View FIGURE 32 CC). pergandei Emery, 1895 (KS and many eastern states) 32 Mandible without enlarged preapical tooth just basal of apicodorsal tooth ( Fig. 33A View FIGURE 33 ) (however a minute denticle is present at midlength of mandible); all setae on anterior margin of scape directed towards apex ( Fig. 33B View FIGURE 33 ); pronotal humeral seta short, stiff and stout ( Fig. 33C View FIGURE 33 )............................................................. boneti Brown, 1959 (TX) - Mandible with enlarged preapical tooth just basal of apicodorsal tooth ( Fig. 33 View FIGURE 33 AA) (with or without a minute denticle at midlength of mandible); one or more pairs of setae on anterior margin of scape directed towards base ( Fig. 33 View FIGURE 33 BB); pronotal humeral seta flagellate ( Fig. 33 View FIGURE 33 CC)............................................................................. 33 33 Smaller species (HW 0.33–0.37) with a minute preapical denticle located at about midlength of mandible ( Fig. 34A View FIGURE 34 ) (global tramp species)....................................... silvestrii Emery, 1906 (CA, TX, and many southeastern states) - Larger species (HW 0.38–0.54) without a minute preapical denticle ( Fig. 34 View FIGURE 34 AA), or if preapical denticle present it is located near the apical portion of the second third of mandible....................................................... 34 34 Mandible with preapical denticle located near the apical portion of the second third of mandible ( Fig. 35A View FIGURE 35 ).... mixta Brown, 1953 (AZ) - Mandible without preapical denticle ( Fig. 35 View FIGURE 35 AA).............. louisianae Roger, 1863 (OK, TX, and many eastern states)

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Hymenoptera

Family

Formicidae