Key to Strumigenys of China (as Pyramica)

This worker key is based on: *[[Media:Xu & Zhou 2004.pdf| Xu, Z. and X. Zhou. 2004. Systematic study on the ant genus Pyramica Roger of China. Acta Zootaxonomica Sinica. 29:440-450.]]

The authors above noted: Followed the key of Bolton, 2000. The species P. formosa (=Strumigenys formosa) which is known only from queens is not included.

This key is from a study that treated species from the now synonymized genus Pyramica. Bolton produced two keys in 2000 for East Asia: Key to Strumigenys of East Asia (as Pyramica) and *Key to Strumigenys of East Asia. The paper that this key is sourced from, and others as well, include species described for Strumigenys after the year 2000.

You may also be interested in: Strumigenys

1

 * With head in full- face view the leading edge of the scape with a row of conspicuous projecting curved hairs, of which one or more, distal to the subbasal bend, distinctly curves toward the base of the scape. These hairs may be spatulate, remiform, spoon-shaped or broadly clavate apically; basal stem of each hair (which may be short) erect or suberect with respect to the long axis of the scape . . . . . 2


 * With head in full- face view the leading edge of the scape lacking projecting hairs that curve toward the base of the scape. Scape edge may have elongate simple straight projecting hairs present or entirely apically directed short hairs that may be simple, narrowly to broadly spatulate, or spoon-shaped; in some species the leading edge may be hairless . . . . . 8

2
return to couplet #1
 * With head in full- face view the dorsolateral margin with a distinctly isolated, very conspicuous, laterally projecting apicoscrobal hair; apicoscrobal hair conspicuously differentiated from other pilosity on the margin, may be simple, clavate or flagellate. (Bolton, 2000) (China: Guangxi Region; Bhutan, Burma, Thailand, Malaysia, Philippines, Indonesia) . . . . . Strumigenys dohertyi


 * With head in full-face view the dorsolateral margin without a distinctly isolated apicoscrobal hair that is conspicuously differentiated from other pilosity on the margin; either hair absent or duplicated by others on the margin . . . . . 3

3
return to couplet #2
 * Mandibles elongate and narrow, linear; in full- face view and at full closure only their extreme apices engage. Leading edge of scape with a large, strongly prominent subbasal lobe . . . . . 4


 * Mandibles subtriangular to triangular, not linear; in full- face view and at full closure they engage for half or more of their exposed length. Leading edge of scape with a gradual subbasal curve or subbasal angle, without a large, strongly prominent subbasal lobe . . . . . 5

4
return to couplet #3
 * Dorsal surface of mandible without longitudinal rows of anteriorly directed spoon-shaped or scale-like hairs. The two pairs of hairs closest to the midline on the anterior dypeal margin short, narrowly spoon-shaped and curved or inclined toward the midline. Orbicular hairs on clypeus all of approximately the same size (China: Taiwan Province; Japan) . . . . . Strumigenys hirashimai


 * Dorsal surface of mandible with two longitudinal rows of anteriorly directed spoon-shaped or scale-like hairs. The two pairs of hairs closest to the midline on the anterior clypeal margin long and strap-like, directed anteriorly and curved slightly away from the midline. Orbicular hairs on clypeus much smaller centrally than near lateral and posterior margin. (China: Guangdong Province) . . . . . Strumigenys lachesis

5
return to couplet #3
 * Pronotal humeral hair present; may be simple, flagellate, remiform or subclavate. (China: Fujian Province) . . . . . Strumigenys emeswangi


 * Pronotal humeral hair absent . . . . . 6

6
return to couplet #5
 * Fully closed mandibles in full- face view with teeth extending from apex of masticatory margin to the point where the margin intersects the anterior clypeal margin. (China: Fujian Province, Taiwan Province, Macao; Cosmopolitan tramp species) . . . . . Strumigenys membranifera


 * Fully closed mandibles in full-fare view with crowded series of small teeth on the distal halves of the masticatory margins, but the proximal halves are edentate and concave, and enclose a broad subovate gap in front of the anterior clypeal margin . . . . . 7

7
return to couplet #6
 * Metanotal groove deeply impressed. Propodeum with a pair of acute teeth. Petiolar node relatively low. (China: Taiwan Province) . . . . . Strumigenys takasago


 * Metanotal groove shallowly impressed. Propodeum without teeth. Petiolar node relatively high (China: Yunnan Province) . . . . . Strumigenys nongba

8
return to couplet #1
 * Petiolar node in profile long and low; either anterior face of node much shorter than the long dorsum, or the anterior face shallowly sloped and grading evenly into the peduncle so that the entire segment is subclavate. Petiolar node in dorsal view long and narrow, sometimes with a posterior peduncle, always much longer than broad and generally at least equal in length to the disc of the postpetiole . . . . . 9


 * Petiolar node in profile short and relatively high; either anterior face of node at least subequal in length to the dorsum, or the anterior face steeply sloped and meeting the peduncle through an obtuse but marked angle, or both. Petiolar node in dorsal view short and broad, usually at least as broad as long and generally shorter than the disc of the postpetiole . . . . . 15

9
return to couplet #8
 * Mandibles elongate and narrow in full- face view; masticatory margin engage only in the apical third or less of their length at full closure; proximally with a large gap between the mandibles, and between them and the anterior clypeal margin; labral lobes visible through the gap; MI > 25. Fully closed mandibles edentate from base to about the midlength in full- face view (Bolton, 2000) (China: Zhejiang Province) . . . . . Strumigenys wilsoni


 * Mandibles stoutly triangular in full- face view; masticatory margins engage throughout their length at full closure; proximally without a gap between the mandibles nor between them and the anterior clypeal margin; labral lobes not visible; MI < 25. Fully closed mandibles dentate from anterior clypeal margin to apex in full- face view . . . . . 10

10
return to couplet #9
 * Dorsal (outer) surface of hind tibia without suberect to erect straight simple projecting hairs; any hairs present are decumbent to closely appressed . . . . . 11


 * Dorsal (outer) surface of hind tibia with suberect to erect straight simple projecting hairs . . . . . 13

11
return to couplet #10
 * Lateral spongiform lobe of petiole in profile merely a small flap at the posterolateral angle of the node. With head in full-face view sides of occipital lobes without freely projecting simple hairs. Dorsum of head from highest point of vertex to occipital margin without erect to suberect straight simple hairs. (China: Taiwan Province; Korea, Japan) . . . . . Strumigenys japonica


 * Lateral spongiform lobe of petiole in profile elongate, extending forward almost to the level of the anterior face of the node. With head in full-face view side of each occipital lobe with 4-5 freely projecting short hairs. Dorsum of head from highest point of vertex to occipital margin with distinct erect to suberect straight simple hairs . . . . . 12

12
return to couplet #11
 * Pronotal dorsum with numerous long erect simple hairs. (China: Taiwan Province) . . . . . Strumigenys formosimonticola


 * Pronotal dorsum without long erect simple hairs. (China: Taiwan Province; Japan) . . . . . Strumigenys benten

13
return to couplet #10
 * With head in full-face view the upper scrobe margin with straight or curved elongate simple hairs that freely project laterally or dorsolaterally beyond the margins; similar or even longer hairs project from the occipital lobes. (China: Taiwan Province; Japan) . . . . . Strumigenys leptothrix


 * With head in full-face view the upper scrobe margin with a continuous row of short anteriorly directed decumbent to appressed hairs only, without elongate simple hairs that freely project beyond the margin; one or two freely projecting simple hairs may occur on the lateral occipital lobes well behind the level of the eyes . . . . . 14

14
return to couplet #13
 * In profile view dorsum of mesonotum distinctly convex. Dorsum of petiolar node almost straight, anterodorsal corner prominent. Dorsum of alitrunk microreticulate. Lateral sides of propodeum microreticulate. (China: Taiwan Province, Guangdong Province, Hong Kong; Thailand) . . . . . Strumigenys elegantula


 * In profile view dorsum of mesonotum only slightly convex. Dorsum of petiolar node roundly convex, without prominent anterodorsal corner. Dorsum of alitrunk finely longitudinally striate and finely reticulate. Lateral sides of propodeum smooth, sparsely striate. (China: Yunnan Province) . . . . . Strumigenys ailaoshana

15
return to couplet #8
 * Dorsal (outer) surfaces of middle and hind tibiae with one or more conspicuous freely laterally projecting long hairs that are at a right-angle or near right-angle to the long axis of the segment; these hairs may be straight, curved or flagellate; one or more similar hairs present on basitarsi . . . . . 16


 * Dorsal (outer) surfaces of middle and hind tibiae and basitarsi with small simple to spatulate decumbent or appressed hairs, or with minute appressed pubescence only; lacking freely laterally projecting long hairs that are at a right-angle or near right-angle to the long axis of the segment . . . . . 17

16
return to couplet #15
 * Cuticle on side of head within the scrobe smooth and shining. Anterior clypeal margin transverse to shallowly concave in full-face view. Dorsal alitrunk smooth and shining. Eye of a single ommatidium. (China: Taiwan Province, Hong Kong; Japan) . . . . . Strumigenys mazu


 * Cuticle on side of head within the scrobe reticulate-punctate. Anterior clypeal margin evenly convex in full-face view. Dorsal alitrunk sculptured, at least in part. Eye of more than one ommatidium. (China: Fujian Province, Taiwan Province; Bhutan; Thailand; Japan) . . . . . Strumigenys kichijo

17
return to couplet #15
 * With the head in full- face view and the mandibles fully closed the dorsal surface of each massively triangular mandible has, near its base, a very distinct sharp transverse rim that extends across the width of the mandible (China: Yunnan Province) . . . . . Strumigenys yangi


 * With the head in full- face view and the mandibles fully closed the dorsal surface of each mandible, near its base, without a sharp transverse rim that extends across the width of the mandible; if dorsum of mandible slightly depressed basally then mandible is linear, not triangular . . . . . 18

18
return to couplet #17
 * With the head in full-fare view the entire dorsum clothed with ground pilosity of very conspicuous pale spoon-shaped to orbicular hairs . . . . . 19


 * With the head in full- fare view the dorsum either without hairs or with ground-pilosity of short hairs that are simple to narrowly spatulate and usually inconspicuous . . . . . 22

19
return to couplet #18
 * Apicodorsal tooth of mandible short, not spiniform, at most only fractionally longer than the apicoventral tooth; at full closure apicodorsal tooth partially overlaps but does not completely cross over the tooth from the opposite mandible, and never projects beyond the outer margin of the opposite mandible (China: Fujian Province) . . . . . Strumigenys sinensis


 * Apicodorsal tooth of mandible spiniform and extremely long, enormously longer than the apicoventral tooth; at full closure apicodorsal tooth completely crosses over the tooth from the opposite mandible and usually projects beyond the outer margin of the opposite mandible . . . . . 20

20
return to couplet #19
 * Apical half of mandible with two preapical teeth, the proximal slightly longer than the distal. With alitrunk in profile posterior surface of mesonotum narrowly convex and weakly bulging, overhanging the metanotal groove. Posterodorsal corner of propodeum dentate. Head broader than long, CI 106-I08 (China: Taiwan Province; Korea; Japan; USA) . . . . . Strumigenys hexamera


 * Apical half of mandible with or without a single- small inconspicuous preapical tooth, if present which located very close to the spiniform apicodorsal tooth. With alitrunk in profile mesonotum meets propodeum at the metanotal groove, the former not narrowly convex nor bulging posteriorly, not overhanging the metanotal groove. Posterodorsal corner of propodeum rounded. Head slightly longer than broad, CI<100 . . . . . 21

21
return to couplet #20
 * Apical half or mandible with a single small inconspicuous preapical tooth, located very close to the spiniform apicodorsal tooth. Dorsal surlace of mandible with 3 longitudinal rows or scale-like to spoon-shaped hairs. Body smaller, with TL 2. 0 mm, HL 0. 50 mm, HW 0. 48 mm (China: Guangdong Province) . . . . . Strumigenys tisiphone


 * Apical half of mandible without any preapical tooth. Dorsal surface of mandible with 2 longitudinal rows of scale-like to spoon-shaped hairs. Body larger, with TL 2.6 mm, HL 0.63 mm, HW 0.60 mm. (China: Yunnan Province) . . . . . Strumigenys dayui

22
return to couplet #18
 * With head in full-face view the outer margins of the fully closed mandibles intersect the anterior clypeal margin mesad of the anterolateral clypeal angles, so that there is a section of the anterior clypeal margin that projects laterally beyond the outer line or the mandible . . . . . 23


 * With head in full-face view the outer margins of the fully closed mandibles intersect the anterior clypeal margin at the anterolateral clypeal angles, so that there is no section of the anterior clypeal margin that projects laterally beyond the outer line of the mandible . . . . . 24

23
return to couplet #22
 * Anterior clypeal margin broadly shallowly transversely concave across its entire width. Mandible with 14 teeth distal of a long low basal lamella. Counting from the basal lamella teeth 1, 3, 5, 7 and 9 are relatively large; the fifth tooth from the lamella is easily the longest on the margin. (China: Zhejiang Province, Hunan Province, Guangxi Region, Hong Kong; japan) . . . . . Strumigenys canina


 * Anterior clypeal margin with a deep semicircular median impression, the anterolateral angles broadly convex on each side or the impression. Mandible with 12 teeth distal of a triangular rounded basal lamella. Counting from the basal lamella teeth 1-5 are relatively large; the third tooth from the lamella is the longest on the margin. (China: Taiwan Province, Fujian Province, Guangxi Region, Hong Kong; Thailand; Japan) . . . . . Strumigenys sauteri

24
return to couplet #22
 * With head in full- face view the fully closed mandibles triangular, with teeth present along entire length of' exposed inner margin; proximal half or inner margin dentate. without a long diastema between basal tooth and basal lamella; without a large space basally through which the apices of the labral lobes are visible. (Bolton, 2000) (China: Cuangdong Province, Hong Kong; Thailand, Philippines, Malaysia, Singapore, Indonesia, Brunei, Papua New Guinea) . . . . . Strumigenys mitis


 * With head in full- face view the fully closed mandibles narrow or elongate-triangular, with teeth present only on distal half of exposed length of inner margin; proximal half of inner margin edentate and forming a long diastema between basal tooth and basal lamella; a large space present basally between the opposed mandibles through which the apices or the labral lobes are visible. (China: Taiwan Province, Yunnan Province, Guangxi Region; Korea; Japan; Malaysia; Singapore; Indonesia) . . . . . Strumigenys mutica