Key to Myrmica pachei-group

This worker key is based on: Chen, Z.L., Zhou, S.Y., Huang, J.H. 2016. Seven species new to science and one newly recorded species of the ant genus Myrmica Latreille, 1804 from China, with proposal of a new synonym (Hymenoptera: Formicidae). ZooKeys 551: 85–128 (doi: 10.3897/zookeys.551.6005).

The Myrmica fauna of China is still poorly known, and many more species certainly remain to be found.

1

Basal third of first gastral tergite densely punctated and longitudinally ruguloso-striated . . . . . Myrmica sculptiventris

Whole surface of first gastral tergite smooth . . . . . 2

2

return to couplet #1

Whole mesosoma dorsum with straight transversal rugae . . . . . 3

Only part of mesosoma dorsum with straight transversal rugae . . . . . 5

3

return to couplet #2

Head distinctly elongate, suboval, with narrowly rounded posterior corners; posterior third of head dorsally without longitudinal rugae and reticulation, but densely punctuate . . . . . Myrmica yani

Head slightly longer than broad, subsquare, with distinctly marked posterior corners; whole head dorsally with longitudinal rugae . . . . . 4

4

return to couplet #3

Lateral and posterior margins of the head with long numerous suberect to erect hairs. Colour lighter, head dorsum dark reddish brown, mesosoma and gaster brownish red . . . . . Myrmica villosa

Lateral margins of head with short decumbent hairs, long suberect hairs present only on the posterior margin and genae. Colour darker, whole body dark reddish brown . . . . . Myrmica pachei

5

return to couplet #2

Lateral and posterior margins of head with long numerous suberect to erect hairs . . . . . 6

Lateral margins of head either glabrous or with short decumbent hairs; if long erect to suberect hairs occur, they are restricted to the posterior margin and genae . . . . . 12

6

return to couplet #5

Head slightly longer than broad (CI < 1.15), subsquare, with distinctly marked posterior corners . . . . . 7

Head distinctly elongate (CI > 1.20), suboval, with barely marked posterior corners . . . . . 9

7

return to couplet #6

Number of rugae between frontal carinae level with the eyes >30; mesonotal and propodeal dorsum with > 35 fine transverse rugae . . . . . Myrmica pleiorhytida

Number of rugae between frontal carinae level with the eyes ≤ 25; mesonotal and propodeal dorsum fine transverse rugae < 20 . . . . . 8

8

return to couplet #7

Petiole with a stronger triangular ventral process; propleuron with rugose; mesonotal and propodeal dorsum with about 20 moderately coarse transverse sinuous rugae . . . . . Myrmica dongi

Petiole with a normal triangular ventral process; propleuron only with densely punctuated; mesonotal and propodeal dorsum with 8−10 coarse sinuous transverse rugae . . . . . Myrmica mifui

9

return to couplet #6

Mesonotal and propodeal dorsum with ≤20 coarser transverse rugae . . . . . 10

Mesonotal and propodeal dorsum with ≥ 25 finer transverse rugae . . . . . 11

10

return to couplet #9

Petiole low, PI1 1.68, its node with elongate flattened dorsum . . . . . Myrmica weii

Petiole higher, PI1 < 1.55, its node with short, slightly convex, gradually sloping posteriorly dorsal surface . . . . . Myrmica multiplex

11

return to couplet #9

Frontal carinae merge with the rugae that extend back to the posterior head margin. Surface of head dorsum between rugae appears shiny . . . . . Myrmica yunnanensis

Frontal curved outwards to merge with the rugae that surround antennal sockets. Surface of the head dorsum between rugae appears dull, coarsely and densely punctuated . . . . . Myrmica heterorhytida

12

return to couplet #5

Propodeal spines long (ESLI > 0.45), massive, widened at the base and often downcurved on their distal third . . . . . Myrmica taibaiensis

Propodeal spine shorter (ESLI < 0.40), slender and straight . . . . . 13

13

return to couplet #12

Head dorsum densely punctate, dull . . . . . 14

Head dorsum not punctate, shiny . . . . . 17

14

return to couplet #13

Head distinctly elongate (CI > 1.20), suboval, with barely marked posterior corners; dorsum of head posterior to eyes with reticulation, rest of head dorsum with longitudinal rugosity . . . . . Myrmica polyglypta

Head slightly longer than broad (CI < 1.15), subsquare, with distinctly marked posterior corners; only occiput and temples with fine reticulation . . . . . 15

15

return to couplet #14

Basal third of first gastral tergite with fine superficial hexagonal sculpture; posterior margin without any erect to suberect long hairs; dorsum of petiolar node with a distinct broad dorsal plate . . . . . Myrmica huaii

Whole gastral tergite smooth and shiny; posterior margin with erect to suberect long hairs; dorsum of petiolar node without a distinct broad dorsal plate . . . . . 16

16

return to couplet #15

Lateral margins of head posterior to eyes with abundant short decumbent hairs; Mesonotal and propodeal dorsum with > 25 moderately thin (not coarse) transverse sinuous rugae; Petiole with relatively short but distinct peduncle, its anterior surface concave, dorsum of node quite narrowly rounded . . . . . Myrmica schulzi

Lateral margins of head posterior to the eyes without short decumbent hairs; Mesonotal and propodeal dorsum with < 20 quite coarse transverse sinuous rugae; petiole low, with distinct peduncle, its anterior surface concave, dorsum of node widely rounded . . . . . Myrmica phalacra