Key to Myrmica of West Europe and North Africa

This key is based on: Radchenko, A.G. & Elmes, G.W. 2010. Myrmica ants of the Old World. Fauna Mundi 3: 1-789.

1

 * Frontal carinae curved outwards to merge with the rugae that surround antennal sockets. Scape very smoothly curved at the base, never angled and without any trace of a lobe or carina . . . . . 2


 * Frontal carinae merging with the rugae that extend to the occipital margin, they do not curve outwards and do not merge with rugae that surround antennal sockets. Scape strongly curved, often angled at the base, usually with (but sometimes without) a lobe, ridge or carina . . . . . 3

2
return to couplet #1
 * Petiolar node with rounded dorsum, without a flattened dorsal plate, node of petiole and postpetiole smooth, at most very finely striated; propodeal spines short, mean ESLI 0.26. Males: scape and tibiae with numerous, rather long standing hairs. - Europe, Caucasus, West Siberia, northern Kazakhstan, Tien-Shan, Pamir, East Siberia, to the east until Transbaikal region . . . . . Myrmica rubra
 * Petiolar node flattened, with a dorsal plate, node of petiole and postpetiole with quite coarse, short sinuous longitudinal rugae; propodeal spines longer, mean ESLI 0.41. Males: scape and tibiae with sparser and short standing hairs. - Transpalaearctic species, distributed from Atlantic to Pacific Oceans, including Japan, Caucasus, absent in Tien-Shan . . . . . Myrmica ruginodis

3
return to couplet #1
 * Scape with a vertical lobe or dent and sharply angled at the base . . . . . 4
 * Scape never with a vertical lobe or dent, varying from gradually curved to sharply angled at the base, often with horizontal lobe, ridge or carina of various shapes . . . . . 13

4
return to couplet #3
 * Frontal carinae very strongly curved, frons extremely narrow (the narrowest among all known Myrmica species), FI < 0.19, FLI > l.95. Scape at the base with an extremely massive, vertical, plate-like lobe. - Albania, former Yugoslavia, Greece, Asia Minor, Transcaucasus . . . . . Myrmica ravasinii
 * Frontal carinae less curved, frons wider, FI > 0.20, FLI < 1.90. Scape at the base with vertical lobe ranging from moderately sized plate-like structure to a small dent . . . . . 5

5
return to couplet #4
 * Foot of scape with extended, shield-like plate. Males: scape short, SI1 < 0.50 . . . . . 6
 * Foot of scape without extended shield-like plate. Males: scape long, SI1 > 0.60 . . . . . 10

6
return to couplet #5
 * Frontal carinae strongly curved, frons narrower, species' means FI ≤ 0.27 . . . . . 7
 * Frontal carinae less curved, frons wider, species' means FI > 0.28 . . . . . 9

7
return to couplet #6
 * Surface of foot of scape strongly excavated. Alitrunk with fairly coarse, more or less straight, longitudinal rugae. - Greece (Peloponnesus Peninsula) . . . . . Myrmica pelops
 * Surface of foot of scape not excavated. Alitrunk with finer sinuous longitudinal rugae . . . . . 8

8
return to couplet #7
 * Frons narrow, mean FI < 0.24, very rarely FI of individuals > 0.25. Males: scape more strongly curved at the base forming less obtuse angle (mean 121°, range 101-130°). - Central and North Europe, Caucasus, West Siberia, northern Kazakhstan, Tien-Shan, East Siberia, to Enisei river in the east . . . . . Myrmica schencki
 * Frons distinctly wider, mean FI 0.27, rarely FI of individuals < 0.25. Males: scape less strongly curved at the base forming more obtuse angle (mean 133°, range 126-144°). - Italy south of Alps . . . . . Myrmica obscura

9
return to couplet #6
 * Frontal lobes less extended, FLI l.23-1.36, mean 1.29. Propodeal spines long, ESLI 0.32-0.42, mean 0.38. Distinctive, unusual shape of scape lobe. Males: scape longer and distinctly curved at the base, subequal to the length of 1-3 funicular segments together, mean SI2 0.45. - Sicily . . . . . Myrmica siciliana
 * Frontal lobes more extended, FLI 1.36-1.52, mean 1.41. Propodeal spines shorter, ESLI 0.18-0.30, mean 0.24. Males: scape very short and not curved at the base, shorter than 1st and 2nd funicular segments together, mean SI2 0.34. - Central Europe, Balkans, south of East Europe, Transcaucasus, Iran, Turkmenistan, south of West Siberia, northern Kazakhstan, Tien-Shan, to Altai Mts. in the east . . . . . Myrmica deplanata

10
return to couplet #5
 * Anterior clypeal margin in female castes and males narrowly rounded, slightly prominent and not-notched medially. Males: scape very long, SI1 > 0.90, SI2 > 0.95. - Spain . . . . . Myrmica xavieri
 * Anterior clypeal margin in female castes and males widely rounded, not prominent and notched medially. Males: scape shorter, SI1 < 0.85, SI2 < 0.90 . . . . . 11

11
return to couplet #10
 * Petiole with well developed peduncle, its anterior surface not steep, distinctly concave, meeting the dorsal one to form an obtuse, rounded angle, petiolar node without a distinct dorsal plate, its dorsum convex or at most slightly flattened (seen in profile); propodeal spines longer, mean ESLI 0.35. Scape at the base with small, often dentiform lobe. Frons wider, mean FI 0.37. - Iberian Peninsula, French Pyrenees . . . . . Myrmica wesmaeli
 * Petiole with short peduncle, its anterior surface steep, only slightly concave, meeting the dorsal one at an acute or right angle, petiolar node with a distinct, declined posteriorly, flattened dorsal plate (seen in profile); propodeal spines shorter, species' means ESLI ≤ 0.30. Scape at the base usually with a distinct lobe (its size may vary, but it is never dentiform). Frons narrower, species' means FI < 0.35 . . . . . 12

12
return to couplet #11
 * Frons relatively narrow, mean FI 0.28. - Boreal species: Europe, Caucasus, Asia Minor, Siberia, northern Kazakhstan, to the east until Transbaikal region . . . . . Myrmica lobicornis
 * Frons relatively wide, mean FI 0.34. - Iberian Peninsula, Canary Islands, southern France, Italy, Switzerland, Austria . . . . . Myrmica lobulicornis

13
return to couplet #3
 * Alitrunk and waist with very coarse, straight (not sinuous) longitudinal rugae; petiole with a very short peduncle, a steep anterior surface that meets the dorsal one at an almost right angle, dorsal plate well developed and flattened. Scape strongly but gradually curved at the base, at most slightly angled, sometimes with a weak longitudinal ridge on the foot of scape. Large and robust species, usually bicoloured, with reddish alitrunk and blackish head dorsum and gaster. Males: scape long, SI1 > 0.80. - Boreal species, distributed from Ireland to Kamchatka, absent in Japan . . . . . Myrmica sulcinodis
 * Alitrunk, and especially waist, with less coarse, usually sinuous longitudinal rugosity; petiole having a different shape, scape of various shapes. Males: scape shorter, SI1 < 0.80, usually < 0.70 . . . . . 14

14
return to couplet #13
 * Clypeus posteriorly with large fovea. - Italy (social parasite) . . . . . Myrmica symbiotica
 * Clypeus without fovea . . . . . 15

15
return to couplet #14
 * Scape gradually curved at the base or at most slightly angled, without an horizontal lobe, at most with a short horizontal ridge or very weak carina (seen under magnification > 50x) . . . . . 16
 * Scape strongly angled at the base, with an horizontal lobe, carina or well developed ridge (seen under magnification> 50x) . . . . . 20

16
return to couplet #15
 * Scape at the base bent in an "ideal" curve, with no trace of an angle, carina or ridge. - Europe, Caucasus, south of West Siberia . . . . . Myrmica gallienii
 * Scape at the base either slightly angled or with a weak horizontal ridge . . . . . 17

17
return to couplet #16
 * Scape at the base slightly angled, with no trace of a ridge. - Central, North and East Europe (absent in British Isles), Balkans and Greece mountains, Caucasus . . . . . Myrmica rugulosa
 * Scape at the base with short ridge or weak carina . . . . . 18

18
return to couplet #17
 * Small species, mean HW 0.79, mean AL 1.28. Scape at the base slightly angled and with a very weak ridge. Tibial spur well developed and pectinate. Pronotal dorsum reticulated. Males: middle and hind tibiae with short hairs. - Ukraine, Poland, southern Finland, Germany, Austria, Switzerland, Czech Republic, Romania, Italy, Serbia, Bulgaria and Greece . . . . . Myrmica constricta
 * Larger species, species' means HW 0.97 ... 1.05, means AL 1.56 ... 1.64. Scape at the base only curved, not angled, with a more developed ridge or weak carina. Tibial spur very often partly reduced, short, simple or only weakly pectinate. Males: middle and hind tibiae with very long hairs . . . . . 19

19
return to couplet #18
 * Only frons with longitudinal rugae, remainder parts of head dorsum with reticulation. Scape at the base with a weak carina. Petiolar node without a distinct dorsal plate. Generally less hairy species. - Iberian Peninsula, Balearic Isl., French Pyrenees . . . . . Myrmica aloba
 * Head dorsum mostly with longitudinal rugae, reticulation, if present, only on occiput. Scape at the base with fine ridge only. Petiolar node flattened to form a declined posteriorly dorsal plate. Generally more hairy species. - Morocco . . . . . Myrmica cagnianti

20
return to couplet #15
 * Frons very narrow, FI ≤ 0.30, mean 0.27. Lobe at the base of scape quite large, but does not extend to form a longitudinal carina on the dorsal surface of scape. – Central Europe, Balkans, central and southern parts of East Europe, southern part of West Siberia, northern Kazakhstan . . . . . Myrmica slovaca
 * Frons wider, FI ≥ 0.30, species' means ≥ 0.33. Base of the scape with ornamentation ranging from a ridge or a distinct carina to a large, well developed lobe, but if the lobe is large, it extends to form a longitudinal carina on the dorsal surface of scape . . . . . 21

21
return to couplet #20
 * Entire head dorsum with coarse reticulation, only lower part of frons with sinuous rugae. Males: scape relatively long, longer than 4 basal funicular segments together, SI1 > 0.60. Head margins with numerous long hairs. - Switzerland, Germany (social parasite) . . . . . Myrmica bibikoffi
 * If present at all, the reticulation on head dorsum is much less extensively developed . . . . . 22

22
return to couplet #21
 * Postpetiole very wide, PPI4 > 0.55; whole body with very abundant, long hairs; frons wide, FI 0.40-0.42. Males: scape relatively long, as long as 4 basal funicular segments together, SI1 > 0.50. Head margins and waist with numerous long hairs. - England, Denmark, Sweden, southern Finland, Netherlands, Germany, Austria, Hungary, southern Poland, Czech and Slovak Republics, Serbia, European part of Russia (social parasite) . . . . . Myrmica hirsuta
 * Postpetiole narrower, PPI4 < 0.45; body with less abundant and shorter hairs. Males: scape of various length . . . . . 23

23
return to couplet #22
 * Frons wide, mean FI 0.40; frontal lobes moderately extended, mean FLl 1.20 (for Balkans populations). Scape at the base distinctly angled with a narrow horizontal lobe, carina or even distinct ridge (size of this structure is quite variable). - Caucasus, Asia Minor, Ukraine (Crimea), Bulgaria, Greece, Italy, Croatia, Slovenia and Serbia . . . . . Myrmica hellenica
 * Frons generally narrower, species' means FI ≤ 0.38; frontal lobes distinctly more extended, means FLI ≥ 1.30. Scape at the base with a much more pronounced, larger horizontal lobe or carina . . . . . 24

24
return to couplet #23
 * Hairy species, petiole with more than 10 (usually with 12-20) long, thin and often curved hairs. Entire alitrunk dorsum with longitudinal, slightly sinuous rugae, without reticulation; postpetiolar dorsum with partly reduced sculpture. Anterior clypeal margin shallowly but distinctly notched medially. Spurs on middle and hind tibiae at least partly rduced and usually not pectinate. Queens: petiolar node with coarse, regular longitudinally-concentric rugosity, without reticulation. Males: scape relatively long, as long as 4 basal funicular segments together, SI1 > 0.50. Head margins with numerous long hairs. - West Europe, Ukraine (Transcarpathian Prov.) (facultative social parasite) . . . . . Myrmica vandeli
 * Generally less hairy species, petiole with less than 10 (usually not more than 8) long, straight, thick hairs. Alitrunk dorsum with strongly sinuous longitudinal rugae and often also with reticulation; postpetiolar dorsum with coarser sculpture. Anterior clypeal margin not-notched medially. Spurs on middle and hind tibiae as a rule well developed and pectinate. Queens: petiolar node with various sculpture, but never with coarse, regular longitudinally concentric rugosity. Males: scape shorter; if the same length (i.e. SI1 > 0.50) then head margins with very short and sparse hairs . . . . . 25 or 30
 * At this point if you have no males or wish to determine species primarily on worker characters go to couplet . . . . . 25
 * Otherwise, to determine species primarily on male characters go to alternative key couplet . . . . . 30

25
return to couplet #24
 * Scape at the base with very large, massive lobe, which is clearly raised over the dorsal plane of scape. Frons narrow, mean FI 0.32. Males: scape relatively long, as long as 4-4.5 basal funicular segments together, SI1 > 0.50. - Central and North Europe, Balkans (from northwestern Italy to Bulgaria), East Europe, Asia Minor, Caucasus, West Siberia and northern Kazakhstan . . . . . Myrmica lonae
 * Scape at the base with smaller and not massive lobe, which is never raised over the dorsal plane of the scape. Males: scape of various lengths . . . . . 26

26
return to couplet #25
 * Frons relatively narrow, species' means FI < 0.35. Scape at the base with relatively large lobe that is more extended posteriorly than anteriorly (either Myrmica sabuleti or Myrmica tulinae which can only be separated with certainty on male characters) . . . . . 27
 * Frons relatively wide, species' means FI ≥ 0.36. Scape at the base with smaller lobe that is more extended anteriorly than posteriorly, or sometimes with only a narrow carina . . . . . 28

27
return to couplet #26
 * Workers: spur of hind and middle tibiae well developed, pectinate. Males: scape relatively long, as long as 4-4.5 basal funicular segments together, SI] > 0.50. - Europe (to southern Sweden, Finland and Norway in the north), Caucasus . . . . . Myrmica sabuleti
 * Workers: spur of hind and middle tibiae often reduced to some extent. Males: scape short, shorter than 1-3 basal funicular segments together, SI] < OAO. - Turkey, Georgia, France, Italy, Netherlands, Poland . . . . . Myrmica tulinae

28
return to couplet #26
 * Propodeal spines relatively short, mean ESLI 0.36; petiolar node without a distinct horizontal dorsal plate, its posterior surface declines gradually to postpetiole. Frons relatively wide, mean FI 0.38; frontal lobes less extended, mean FLI 1.32. Males: scape short, SI] < 0.45. Middle and hind tibiae and basitarsi with short hairs, they are shorter than maximum width of tibia. - Europe (to southern England and Denmark in the north), Caucasus, Asia Minor, Iran, Turkmenistan, south of West Siberia, northern Kazakhstan, to Altai Mts. in the east . . . . . Myrmica specioides
 * Propodeal spines longer, species' means ESLI > 0.40; petiole usually with a distinct horizontal or slightly declined posteriorly dorsal plate, its posterior surface falls abruptly to postpetiole, often appearing as a distinct step. Frons somewhat narrower, species' means FI 0.36 … 0.37; frontal lobes variously extended. Males: scape of various length. Middle and hind tibiae and basitarsi with longer hairs, they are longer than maximum width of tibia . . . . . 29

29
return to couplet #28
 * Workers: frontal lobes more extended, mean FLI 1.42. Males: scape short, as long as 3-3.5 basal funicular segments together, SI1 < 0.45. - Europe, Caucasus, Asia Minor, northern Kazakhstan, West Siberia; the easternmost confirmed locality - vicinity of Krasnoyarsk (ca. 93°E) and 100 km N of Kansk (ca. 96°E) . . . . . Myrmica scabrinodis
 * Workers: frontal lobes less extended, mean FLI 1.33. Males: scape relatively long, as long as 4- 4.5 basal funicular segments together, SI1 > 0.50. - South-west of Mediterranean Region (Iberian Peninsula, southern France, Italy) . . . . . Myrmica spinosior

=Altenative key based primarily on male characters=

30
return to couplet #24
 * Males: scape relatively long, as long as 4-4.5 basal funicular segments together, SI1 > 0.50 (Myrmica lonae, Myrmica sabuleti, Myrmica spinosior, these species can only be separated with certainty on worker characters) . . . . . 31
 * Males: scape short, as long as 3-3.5 basal funicular segments together, SI1 < 0.45 . . . . . 33

31
return to couplet #30
 * Workers: scape at the base with very large, massive lobe, which is clearly raised' over the dorsal plane of scape. Frons narrow, mean FI 0.32. - Central and North Europe, Balkans (from northwestern Italy to Bulgaria), East Europe, Asia Minor, Caucasus, West Siberia and northern Kazakhstan . . . . . Myrmica lonae
 * Workers: scape at the base with smaller and not massive lobe, which is never raised over the dorsal plane of scape . . . . . 32

32
return to couplet #31
 * Workers: frons narrow, mean FI 0.33. - Europe (to southern Sweden, Finland and Norway in the north), Caucasus . . . . . Myrmica sabuleti
 * Workers: frons wider, mean FI 0.37. - South-west of Mediterranean Region (Iberian Peninsula, southern France, Italy) . . . . . Myrmica spinosior

33
return to couplet #30
 * Males: middle and hind tibiae and tarsi with short hairs, they are shorter than maximum width of tibia. Workers: frons relatively wide, mean FI 0.38; frontal lobes less extended, mean FLI 1.32. Scape at the base usually with narrow lobe or even carina. Propodeal spines shorter, mean ESLI 0.36; petiolar node without a distinct horizontal dorsal plate, its posterior surface declines gradually to postpetiole. - Europe (to southern England and Denmark in the north), Caucasus, Asia Minor, Iran, Turkmenistan, south of West Siberia and northern Kazakhstan, to the Altai Mts. in the east . . . . . Myrmica specioides
 * Males: middle and hind tibiae and tarsi with very long erect, often curved hairs, they are distinctly longer than maximum width of tibia. Workers: frons narrower, species' means FI 0.34 ... 0.36; frontal lobes more extended, species' means FLI > 1.40. Scape at the base usually with more developed, sometimes large lobe. Propodeal spines longer, means ESLI > 0.40; petiole usually with a distinct horizontal or slightly declined posteriorly dorsal plate, its posterior surface falls abruptly to postpetiole, often appearing as a distinct step (Myrmica tulinae and Myrmica scabrinodis, these species can only be separated with certainty on worker characters) . . . . . 34

34
return to couplet #33
 * Workers: frons relatively narrow, mean FI 0.34. Scape at the base with relatively large lobe. - Turkey, Georgia, France, Italy, Netherlands, Poland . . . . . Myrmica tulinae
 * Workers: frons wider, mean FI 0.36. Scape at the base usually with much smaller lobe, or even with carina. - Europe, Caucasus, Asia Minor, northern Kazakhstan, West Siberia; the easternmost confirmed locality - vicinity of Krasnoyarsk (ca. 93°E) and 100 km N of Kansk (ca. 96°E) . . . . . Myrmica scabrinodis

=A key for the identification of the socially-parasitic Myrmica species of West Europe and North Africa (queens)=

1

 * Scape at the base strongly angled or only curved, but always with a horizontal lobe or at least well developed carina . . . . . 2
 * Scape at the base only curved, always without lobe or carina . . . . . 4

2
return to couplet #1
 * Scape at the base gradually curved, with narrow horizontal carina. Eyes with conspicuous hairs, length of the longest hairs 0.035 mm. – Italy . . . . . Myrmica laurae
 * Scape at the base strongly angled, with more developed horizontal lobe. Eyes usually without hairs, or if present, they are inconspicuous and very short, length of the longest hairs ≤ 0.01 mm . . . . . 3

3
return to couplet #2
 * Large species (HW 1.22-1.24 mm). Frons quite narrow (FI 0.34-0.35). Only frons with longitudinal sinuous rugae, remainder part of head dorsum with coarse reticulation. - Switzerland, Germany . . . . . Myrmica bibikoffi
 * Smaller species (HW 0.80-1.10 mm). Frons wider (FI 0.39-0.46). Head dorsum mainly with longitudinal, slightly sinuous rugae, only its rear third with reticulation. - England, Denmark, Sweden, southern Finland, Netherlands, Germany, Austria, Hungary, southern Poland, Czech and Slovak Republics, Serbia . . . . . Myrmica hirsuta

4
return to couplet #1
 * Scape relatively short, SI1 < 0.76, SI2 < 0.70. Petiolar node (seen in profile) subtriangular. - Switzerland . . . . . Myrmica myrmicoxena
 * Scape longer, SI1 > 0.80, SI2 > 0.85. Petiolar node (seen in profile) with broadly rounded dorsum . . . . . 5

5
return to couplet #4
 * The basal half of the first gastral tergite with conspicuous, fairly long, suberect hairs; postpetiolar dorsum with distinct reticulation. - France, Spain . . . . . Myrmica lemasnei
 * First gastral tergite with only sparse, short, decumbent pubescence; postpetiolar dorsum without reticulation . . . . . 6

6
return to couplet #5
 * Surface of head, alitrunk and waist finely but densely punctated, appears dull; petiolar and postpetiolar nodes with relatively short, straight or slightly downward-curved hairs. - Algeria . . . . . Myrmica kabylica
 * Surface of head, alitrunk and waist smooth or at most superficially punctated, appears shiny; petiolar and postpetiolar nodes with fairly long, downward-curved hairs. - East, Central and North Europe . . . . . Myrmica karavajevi

=A key for the identification of the socially-parasitic Myrmica species of West Europe and North Africa (males)=

1

 * Antennae 12-segmented . . . . . 2
 * Antennae 13-segmented . . . . . 5

2
return to couplet #1
 * Eyes with conspicuous hairs, length of the longest hairs 0.04 mm. Propodeum with pointed teeth. - Italy . . . . . Myrmica laurae
 * Eyes usually with no hairs, or if present, they are inconspicuous and very short, length of the longest hairs ≤ 0.01 mm. Propodeum with short blunt denticles . . . . . 3

3
return to couplet #2
 * Surface of alitrunk (especially of scutum and scutellum) finely but densely punctated, appearing dull. - Algeria . . . . . Myrmica kabylica
 * Surface of alitrunk not punctated, smooth and appearing shiny . . . . . 4

4
return to couplet #3
 * First gastral tergite with only sparse short decumbent pubescence. - East, Central and North Europe . . . . . Myrmica karavajevi
 * Basal half of first gastral tergite with conspicuous, fairly long suberect hairs. - France, Spain . . . . . Myrmica lemasnei

5
return to couplet #1
 * Head margins with short hairs; antennal scape short (SI1 = SI2 = 0.35). Switzerland . . . . . Myrmica myrmicoxena
 * Head margins with long hairs; antennal scape longer (SI1 > 0.40, SI2 > 0.45) . . . . . 6

6
return to couplet #5
 * Lateral and posterior parts of head dorsum with distinct reticulation - Switzerland, Germany . . . . . Myrmica bibikoffi
 * Lateral and posterior parts of head dorsum without reticulation, at most with longitudinal striation or sometimes only punctated. - England, Denmark, Sweden, southern Finland, Netherlands, Germany, Austria, Hungary, southern Poland, Czech and Slovak Republics, Serbia . . . . . Myrmica hirsuta