Narrow Headed Ant

Formica exsecta Nylander, 1846a PDF: 909, pl. 18, fig. 20 (w.q.m.) FINLAND. Palearctic. AntCat AntWiki HOL

Taxonomic history

Combination in Formica (Adformica): Lomnicki, 1925a PDF: 14 (in key).Combination in Formica (Coptoformica): Müller, 1923b PDF: 146.Combination in Coptoformica: Röszler, 1950 PDF: 211.Status as species: Foerster, 1850a: 23; Schenck, 1852 PDF: 38; Mayr, 1855 PDF: 340 (redescription); Nylander, 1856b PDF: 63; Gredler, 1858 PDF: 8; Smith, 1858a PDF: 4; Mayr, 1861 PDF: 46 (in key); Meinert, 1861: 317; Mayr, 1863a PDF: 414; Roger, 1863b PDF: 13; Smith, 1871c: 1; Dours, 1873 PDF: 165; Forel, 1874 PDF: 51 (in key); André, 1874b: 183 (in key); Emery, 1878: 48; Emery & Forel, 1879 PDF: 450; Saunders, 1880 PDF: 206; André, 1882c PDF: 178 (in key); White, 1884 PDF: 251; Nasonov, 1889: 15; Lameere, 1892: 62; Forel, 1892j PDF: 307; Dalla Torre, 1893 PDF: 195; Ruzsky, 1896 PDF: 68; Saunders, 1896 PDF: 21; Ruzsky, 1902d PDF: 10; Ruzsky, 1903c PDF: 206; Ruzsky, 1905b: 353; Wasmann, 1906 PDF: 111 (in key); Emery, 1909b PDF: 189; Bondroit, 1910 PDF: 483; Yano, 1910a PDF: 422; Wheeler, 1913i PDF: 489 (redescription); Stitz, 1914 PDF: 91; Ruzsky, 1914b PDF: 103; Emery, 1914c PDF: 159; Ruzsky, 1915b: 9; Forel, 1915d: 56 (in key); Donisthorpe, 1915f: 273; Wolf, 1915 PDF: 46; Emery, 1916a PDF: 256; Ruzsky, 1916: 5; Escherich, 1917: 335 (in key); Bondroit, 1918 PDF: 61; Nadig, 1918 PDF: 341; Kulmatycki, 1922 PDF: 83; Soudek, 1922b PDF: 81; Müller, 1923b PDF: 146; Vashkevich, 1924b PDF: 147; Emery, 1925d PDF: 257; Lomnicki, 1925a PDF: 14 (in key); Ruzsky, 1925a PDF: 287; Ruzsky, 1925b PDF: 43; Karavaiev, 1926e PDF: 195; Kuznetsov-Ugamsky, 1926c PDF: 96; Stärcke, 1926a PDF: 146 (in key); Donisthorpe, 1927c: 316; Karavaiev, 1927d: 283 (in key); Kuznetsov-Ugamsky, 1928b PDF: 15; Donisthorpe, 1929a: 447; Kuznetsov-Ugamsky, 1929a PDF: 23; Kuznetsov-Ugamsky, 1929b PDF: 38; Wheeler, 1929g PDF: 10; Karavaiev, 1930b PDF: 149; Karavaiev, 1931e PDF: 217; Arnol'di, 1933a: 603 (in key); Grandi, 1935 PDF: 103; Karavaiev, 1936: 252 (redescription); Ruzsky, 1936 PDF: 91; Menozzi, 1939a PDF: 321 (in key); Novák & Sadil, 1941 PDF: 104 (in key); Holgersen, 1942b PDF: 11; Holgersen, 1943c PDF: 176 (in key); Holgersen, 1944a PDF: 184; Ruzsky, 1946 PDF: 69; Röszler, 1950 PDF: 211; Betrem, 1954 PDF: 224; Ceballos, 1956: 318; Kutter, 1957 PDF: 11 (in key); Dlussky, 1962 PDF: 182; Dlussky, 1964 PDF: 1027 (redescription); Baroni Urbani, 1964c PDF: 169; Dlussky, 1965a PDF: 26; Dlussky, 1967a PDF: 100; Bernard, 1967a PDF: 323 (redescription); Kutter, 1968b: 61; Kutter, 1968c: 206; Collingwood & Yarrow, 1969 PDF: 90; Baroni Urbani, 1971c PDF: 225; Collingwood, 1971 PDF: 166; Dlussky & Pisarski, 1971 PDF: 194 (redescription); Banert & Pisarski, 1972 PDF: 356; Parapura, 1972 PDF: 763; Bolton & Collingwood, 1975: 6 (in key); Pisarski, 1975: 51; Azuma, 1977a PDF: 117; Van Boven, 1977 PDF: 157; Kutter, 1977c: 283; Arnol'di & Dlussky, 1978: 552 (in key); Collingwood, 1978 PDF: 93 (in key); Collingwood, 1979 PDF: 129; Kupyanskaya, 1980 PDF: 102; Kupyanskaya, 1986b PDF: 98; Agosti & Collingwood, 1987a PDF: 59; Agosti & Collingwood, 1987b PDF: 285 (in key); Nilsson & Douwes, 1987: 77; Agosti & Hauschteck-Jungen, 1988 PDF: 280; Kupyanskaya, 1990a: 200; Atanassov & Dlussky, 1992: 282; Arakelian, 1994 PDF: 95; Radchenko, 1994b: 112 (in key); Douwes, 1995: 97; Bolton, 1995b: 194; Poldi et al., 1995: 8; Tang et al., 1995: 104; Espadaler, 1997g PDF: 28; Gallé et al., 1998: 218; Tinaut & Martínez-Ibañez, 1998d PDF: 36 (in key); Seifert, 2000a PDF: 525 (redescription); Czechowski et al., 2002 PDF: 89; Karaman & Karaman, 2003 PDF: 49; Karaman & Karaman, 2005 PDF: 59; Markó et al., 2006 PDF: 67; Petrov, 2006 PDF: 111 (in key); Schultz et al., 2006 PDF: 203; Bračko, 2007 PDF: 19; Radchenko, 2007 PDF: 36; Seifert, 2007: 322; Werner & Wiezik, 2007 PDF: 143; Zryanin & Zryanina, 2007 PDF: 234; Casevitz-Weulersse & Galkowski, 2009 PDF: 481; Lapeva-Gjonova et al., 2010 PDF: 48; Boer, 2010: 21; Csosz et al., 2011 PDF: 59; Karaman, 2011a PDF: 83; Legakis, 2011 PDF: 35; Borowiec & Salata, 2012 PDF: 493; Czechowski et al., 2012: 228; Guénard & Dunn, 2012 PDF: 31; Kiran & Karaman, 2012 PDF: 11; Borowiec, 2014 PDF: 74; Bračko et al., 2014 PDF: 19; Lebas et al., 2016: 170; Radchenko, 2016: 309; Salata & Borowiec, 2018c 10.5281/zenodo.2199191 PDF: 44; Seifert, 2018: 335; Seifert, 2019 10.3897/dez.66.34868 PDF: 56.Senior synonym of Formica dalcqi: Dlussky & Pisarski, 1971 PDF: 194; Bolton, 1995b: 194; Seifert, 2000a PDF: 526; Casevitz-Weulersse & Galkowski, 2009 PDF: 481; Radchenko, 2016: 309.Senior synonym of Formica etrusca: Dlussky, 1967a PDF: 100; Bernard, 1967a PDF: 323; Dlussky & Pisarski, 1971 PDF: 194; Bolton, 1995b: 194; Seifert, 2000a PDF: 525; Radchenko, 2016: 309.Senior synonym of Formica exsecta exsectopressilabris: Bernard, 1967a PDF: 323; Dlussky & Pisarski, 1971 PDF: 194; Van Boven, 1977 PDF: 157; Bolton, 1995b: 194; Seifert, 2000a PDF: 525; Czechowski et al., 2002 PDF: 89; Casevitz-Weulersse & Galkowski, 2009 PDF: 481; Czechowski et al., 2012: 228; Radchenko, 2016: 309.Senior synonym of Formica kontuniemii: Dlussky, 1967a PDF: 100; Dlussky & Pisarski, 1971 PDF: 194; Pisarski, 1975: 51; Bolton, 1995b: 194; Seifert, 2000a PDF: 526; Czechowski et al., 2002 PDF: 89; Czechowski et al., 2012: 228; Radchenko, 2016: 309.Senior synonym of Formica nemoralis: Seifert, 2000a PDF: 526; Radchenko, 2016: 309.Senior synonym of Formica rubens: Dlussky, 1964 PDF: 1027; Dlussky, 1967a PDF: 100; Bernard, 1967a PDF: 323; Bolton, 1995b: 194; Seifert, 2000a PDF: 525; Czechowski et al., 2002 PDF: 89; Casevitz-Weulersse & Galkowski, 2009 PDF: 481; Czechowski et al., 2012: 228; Radchenko, 2016: 309; Seifert, 2019 10.3897/dez.66.34868 PDF: 58.Senior synonym of Formica exsecta sudetica: Dlussky, 1967a PDF: 100; Dlussky & Pisarski, 1971 PDF: 194; Pisarski, 1975: 51; Bolton, 1995b: 194; Seifert, 2000a PDF: 526; Czechowski et al., 2002 PDF: 89; Czechowski et al., 2012: 228; Radchenko, 2016: 309.Senior synonym of Formica exsecta wheeleri Stitz, 1939: Dlussky, 1967a PDF: 100; Dlussky & Pisarski, 1971 PDF: 194; Bolton, 1995b: 194; Radchenko, 2016: 309.

This ant makes small nest mounds, which reach 25 cm in height and are around 30 cm in diameter. The core of the nest is either a tussock of grass or soil, covered with a 'thatch' of pieces of grass, heather and pine needles (4). The nests are located in sunny positions, which maximise the amount of sunlight falling on them (4). Coupled with the heat produced by the workers and the thatching (which helps to conserve heat) the nests are warmer than the surrounding soil (2). The nests usually have more than one queen and around 1000 workers. Although most recent records are of single, isolated nests, aggregations of 10-30 nests were once common, in which the workers of different nests interact without aggression (4). Usually, however the workers are extremely aggressive, and even attack larger wood ants, climbing onto the back of their opponent and decapitating them (4). The workers tend aphids in order to obtain 'honeydew', a sweet substance excreted by the aphids. Invertebrates are also caught or scavenged and taken back to the colony (4). Winged males and females fly in July and August. The fertilised females may return to their nest, or establish a new colony (4).

Work to conserve the narrow headed ant has been funded by English Nature's Species Recovery Programme. The species has been identified as a priority for conservation under the UK Biodiversity Action Plan (UK BAP), and a Species Action Plan has been produced. The aims of this plan include the restoration of this ant to 10 populations in suitable locations before 2005 (3).

The workers of this endangered ant can be distinguished from other wood ants by the characteristic deep notch on the back of the head (2). It is a medium-sized ant, red and dark brown in colour, and is aggressive (4). The wood ants are the largest of the British ants, all of which are reddish in colour and have a single segment forming the 'waist' (2). Reproductive females (queens) and males are larger than the workers, and have well-developed thoraxes and wings (which are shed from the body after mating). Males have obvious sex organs that protrude from the abdomen (2).

Inhabits open lowland heathland or moorland in southern England and Caledonian pine forest in Scotland (4), where it is found in glades and at the forest edge (2). It may occasionally be found in rides and clearings in woodland, in scrub and by roads or paths (4).

This ant is restricted to parts of southern England and the Scottish Highlands (4). In England, old records exist from the New Forest, Bournemouth, and parts of South Devon. There was also a population on the Isle of Wight, but the species has not been found there since 1913 (4). In Scotland it is known mainly from the mid Spey Valley, including the forests around Loch Morlich, Abernethy Forest and Carrbridge (4). It is currently only known in England from two sites in south Devon (5). It has undergone a serious decline, and it is thought that it may become extinct in England in the near future (4). This ant has a wide but patchy distribution in Europe (3). Elsewhere it if found from southern Spain reaching as far east as Mongolia and northern China, and from the Appenines to Arctic Scandinavia in the north (4).

Classified as Endangered in Great Britain (3).

The narrow headed ant has suffered as a result of habitat loss. In England heathland has been lost due to development, agriculture or forestry, or degraded due to unsuitable management, such as overgrazing, or through scrub invasion (3). In Scotland, native pine forests have been lost for similar reasons; a particular problem has been the intensive management of this habitat for game species (3). Other, more competitive species of ant may pose a threat; the southern wood ant (Formica rufa) is thought to over-run nests of the narrow headed ant (4). Fire, quarrying, and motorbike scrambling also pose threats to the fragile habitat, and the ant colonies (5).

Animal / guest
larva of Clytra quadripunctata is a guest in nest of Formica exsecta
Other: major host/prey

In Great Britain and/or Ireland:
Animal / slave maker
Formica exsecta makes a slave of adult of Formica lemani

Animal / parasite
Formica exsecta parasitises nest (queenless) of Formica fusca

Animal / honeydew feeder
adult of Formica exsecta feeds on honeydew Aphidoidea
Other: major host/prey

Animal / predator
Tetrao urogallus is predator of adult of Formica exsecta
Remarks: Other: uncertain

Records

(Map 64): Bulgaria ( Emery 1914 , Agosti and Collingwood 1987a , Seifert 2000c ); Predbalkan [ Wesselinoff 1973 (as Coptoformica exsecta )]; Central Predbalkan: Dermantsi vill. (Lukovit) ( Atanassov 1934 ); Stara Planina Mts [ Bobev 1972 , Wesselinoff 1973 (as Coptoformica exsecta ), Vatov and Bobev 1976 , Atanassov and Dlusskij 1992 ]; Western Stara Planina Mts: Gerana mine (Vratsa district), Petrohan-Kom ( Atanassov 1936 ); Central Stara Planina Mts: Vezhen hut, Zhaltets peak, Bratanitsa peak ( Atanassov 1936 ), Dobrila peak [ Wesselinoff 1973 (as Coptoformica exsecta )], Tsarichina reserve (under Vezhen peak), Dermenka hut ( Atanassov and Dlusskij 1992 ); Viskyar Mt., Lyulin Mt., Verila Mt. [ Wesselinoff 1973 (as Coptoformica exsecta )]; Vitosha Mt. [ Atanassov 1934 , 1936 , 1952, Wesselinoff 1967 , 1973 (as Coptoformica exsecta ), Atanassov and Dlusskij 1992 ]: Momina skala loc. ( Atanassov 1934 ); Plana Mt. [ Wesselinoff 1967 , 1973 (as Coptoformica exsecta )]; Sredna Gora Mts ( Bobev 1972 , Vatov and Bobev 1976 ); Osogovo-Belasitsa group ( Vatov and Bobev 1976 ); Osogovska Planina Mt., Slavianka Mt., Belasitsa Mt. ( Atanassov and Dlusskij 1992 ); Rila-Pirin group ( Bobev 1972 , Vatov and Bobev 1976 ); Rila Mt. [ Wesselinoff 1973 (as Coptoformica exsecta ), 1979, Vesselinov 1981 , Atanassov and Dlusskij 1992 ]: Elenin peak ( Forel 1892 ), Parangalitsa reserve [ Wesselinoff 1968 and 1973 (as Coptoformica exsecta )], Ibar reserve ( Atanassov 1983 ); Pirin Mt. [ Wesselinoff 1973 (as Coptoformica exsecta ), 1979 , Vesselinov 1981 , Atanassov and Dlusskij 1992 ]; Rhodopi Mts [ Wesselinoff 1973 (as Coptoformica exsecta ), 1979 , Vesselinov 1981 , Atanassov 1983 , Atanassov and Dlusskij 1992 ]; Western Rhodopi Mts: Devin ( Lapeva-Gjonova in press (a) ); Eastern Rhodopi Mts ( Bobev 1972 , Vatov and Bobev 1976 ).

Formica exsecta , Nyl. Adno, Mon. Form. Bor. 909.9; Form. Fr.

et d'Alger. 63.17.

Foerst. Hym. Stud. Form. 23. 8.

Schenck, Beschr. Nass. Ameis. 38.

Mayr. Form. Austr. 68. 14; Ungar. Ameis. 10. 14.

Hab. France; Germany; Austria; Finland; Lapland; Hungary.

Operaria: ferrugineo-rufa parum nitida, abdomine castaneoatro; palpis, antennarum flagellis et vertice fuscescentibus; occipite late emarginato; squama cordata, supra profunde exsecta; pedibus sparse pilosis.

Femina: testaceo-rufa flavido-pubescens nitida; palpis, antennis, fronte cum vertice, thorace supra et abdomine castaneoatris; clypei disco, mesosterno et mesopleuris fuscescentibus; occipite late emarginato; squama cordata vel supra profunde exsecta; alis hyalinis obsoletissime fuscedine tinctis, nervis cinereo-flavidis, stigmate parum fusciori.

Mas: niger parum nitidus brevius pubescens, genitalibus et pedibus vel totis vel ad partem testaceo-pallescentibus; occipite parum emarginato; squama transversim subrectaugulari crassa, supra late concaviuscula; alis hyalinis stigmate fusco.

Hab. saltem in patria usque in Lapponiam frequenter; versatur iisdem locis ac F. rufa , sed magis aprica amare videtur; acervos minores, supra plerumque planos, construit. Examinat in Fennia praesestim circa d. 20 Julii. Marem adhuc d. 11 Aug. (1845) in Ostrobottnia media invenit Stud. F. Hellstroem. Feminam oviparam semel d. 8 Julii (eodem anno) in nido juxta Helsiugforsiam deprehendi.

[[ worker ]]. Long. 2 - 2 1 / 2 lin. Parum nitida, colorata ut supra dictum; minora tamen individua verticem castaneo-fuscam, antennas fere totas et pedum saltem tibias fuscescentes habent. A. F. rufa, cui leviter inspecta similis videtur, differt jam: mandibulis magis complanatis, occipite concavo, clypeo margine inferiori magis truncato, supra vestigio cannulas medianae, squama cordata h. e. ovata sursum parum latiori, supra semiovaliter excisa, colore abdominis atriori, pubescentia denique corporis conspicuiori (canitie sericeo-micante vix alia). Palpi labiales articulo ultimo oblongo, longitudine 3: tii. Metanotum a latere visum arcuatum. Pedes pilis sparsis obsiti; tibiis latere interiori versus apicem sparse setulosis. Segmentutn anale rufescens.

[[ queen ]]. Long. 3 1 / 4 lin. Sat longe flavido-pubescens valde nitida, capite fere lit in [[ worker ]]. Clypeus obsolete convexiuscula, margine infero tenui in medio recta late truncalo; vestigio vix ullo carinulae. Linea frontalis elevatiuscula. Oculi parce pilosuli, pilis his nonnullis parvis tenuibus apice flexis. Thorax mesonoto toto cum parte adjacente prothoracis, scutello, postscutello, mesopleuris et mesosterno obscurius vel dilutius infuscalis. Alas ut in diagnosi, stigmate pallide fusco; anticae 3 1 / 3 lin. longae. Pedes pubescentes, tibiis cum tarsis saepe cinerascentibus vel obscurioribus. Squama ut in [[ worker ]] valde compressa, profunde semiovaliter exsecta. Abdomen nitidum crebre subtiliter flavido pubescens, pubescentia ventris longiori. Basis abdominis truncata macula magna et segmentum anale rufa.

[[ male ]]. Long. 3 - 3 1 / 4 iin. Similis mari F. rufae, sed magis nitidus, occipite concaviusculo alarumque colore nullo statim distinguitur. Brevius flavido pubescens quam [[ queen ]], abdominis pubescentia subtiliori decumbente. Oculi, ut in [[ queen ]], tenuissime pilosuli; ocelli in cacumine verticis elevatiusculi. Alae hyalinae ne minimis, fere vestigiis fuscescentiae, nervis flavido-cinereis, stigmate fusco; anticas fere 3 1 / 4 lin. longas. Pedes vel pallescenti-cinerei, coxis obscurioribus vel femoribus fere totis cum tibiis tarsisque pallide testaceis pubescentia flavida cinerascentibus. Genitalia fere ut in F. rufa . Marginibus segmentorum certo situ magis nitidis, concoloribus.

Obs. Sub nomine F. emarginata Latr . a Cel. Dah 1 bom specimen quoddam feminenm male sub itinere mutilatum absque loco adnotato recepi. Simillima nostras descriptas F. exaectae videlur, sed alis magis fere albescentibus, nervis et stigmate flavidis, palporum labialinm articulo ultimo longiovi, cylindrico; alias differentias e reliquiis mutilatis eruere nequeo. Forte sit vera F. emarginata Latr . Fourm. 163, pl. VI, fig. 33. [[ worker ]] [[ queen ]] [[ male ]], quae a F. exsecta nostra bene est distincta: [[ worker ]] " squama subemarginata " (vel ut infra eodem loco definitur: " avec le bord superieur presque droit un peu echancre au milieu "); [[ male ]] [[ queen ]] alis albis nervis flavidis. Descriptio vero maris praecipue differentias praebet: " Le corps est d'un brun rougeatre. La tete est plus foncee, avec les mandibules plus rougeatres. Les antennes et les pattes sont d'un brun plus clair " & cet. 1. c. pag. 165. Mores et nidificatio praeterea omnino diversa. " Cette espece ( F. emarginata ) etablit sa demeure dans les fentes des murailles et dans les vieux arbres. Elle sent nn peu le musc. Friande de sucreries elle penetre en quantite dans les armoires ou l'on en conserve, et y fait promptement un grand degat. " 1. c. - lu Fennia hucusque non detecta est, quantum scio, hasc species, in Europa media et australi frequenter obvia.

Nyl. Adn. p. 909, 9.

Operaria: Ferrugineo-rufa, parum nitida, abdomine castaneo atfo; palpis, antennarum flagellis et vertice fuscescentibus; occipite late emarginata; mandibulis gnbtlliter confertim rugulosis; foveolis lateralibus clypei et area frontali subtilissime rugulosis, opacis; oculis parce pilosulis; squama cordata, supra profunde exsecta; pedibus sparse pilosis, - Lg. 2 l/2 lin.

Femina: Testaceo-rufa, flavidopubescens, nitida; palpis, antennis, fronte cum vertice, thorace supra et abdomine castaneo-atris; clypei disco, mesosterno et mesopleuris fuscescentibus; occipite late emarginata; squama cordata, vel supra profunde exsecta; alis hyalinis, obsoletissime fuscedine tiaetis, nervis cinereo-flavidis, stigmate parum fascítori . - Lg. 3 1/4 lin.

Mas: Niger, parum nitidus brevius pubescens , geniltalibus et pedibus vel totis vel ad partem testacco-pallescentibus; occipite parum emarginata, squama transversim subrectangulari crassa, sapra late concaviuscula; alis hyalinis, stigmate fusco. - Lg. 3 - 3 1/4 lin.

Der Kopf des Arbeiters ist roth, die Stirn und der sehr breit ausgerandete Scheitel meist braun oder bräunlich , selten fast ganz roth; die Mandibeln dicht längsrunzlig , Zwischen den Runzeln mit gröberen , ziemlich deutlichen Punkten; der Clypeus fein runzlig, auch die - Seiten - gruben, daher matt, kaum mit der Spur eines Mittelkiels; die area frontalis schmal, nach oben sehr stark zugespitzt, ebenfalls sehr fein runzlig, ohne Glanz; die Augen fein haarig, die Nebenaugen sehr klein; die Stirnrinne schwach, bis zum mittleren Nebenauge reichend. Der Mittelleib roth, selten auf dem Vorderbrustrücken mit einem bräunlichen Querschatten. Der Hinterbrustrücken sanft gewölbt , so daß der Basaltheil fast unmerklich in den abschüssigen Theil übergeht . Die Beine roth, die Schenkel- nach der Spitze hin und die Schienen mitunter schwach bräunlich . Kopf und Mittelleib sind äußerst fein runzlig, mit anliegenden, greisen, etwas zerstreuten Härchen bekleidet; Borstenhaare fehlen oder höchstens stehen einige auf dem Scheitel. Der Hinterleib hat dagegen außer der gewöhnlichen anliegenden und noch etwas zerstreuteren Behaarung auch noch gelbliche Borstenhaare, die auf dem Rückenaußer der gewoehnlichen Reihe am Hinterrande der Segmente äußerst sparsam erscheinen, an der Spitze des Hinterleibs aber und auf der Bauchseite häufiger und deutlicher hervortreten. Die Sculptur ist fein runzlig; der Glanz schwach, fast matt, nur unter günstig einfallendem Lichte bemerkt man einen weißlichen Seidenschimmer. Die Schuppe ist tief und fast winklig eingeschnitten, ohne Wimperhaare.

Das Weibchen hat lange, gelbliehe Borstenhaare und ist stark glänzend , der Kopf desselben fast wie bei dem Arbeiter. Der Clypeus schwach gewölbt , am Mundrande in der Mitte weit aber schwach abgestutzt, kaum eine Spur von Kiel zeigend. Die Stirnrinne etwas erhaben. Die Augen sparsam behaart, einige von diesen zarten, kurzen Härchen an der Spitze gebogen. Am Thorax ist der ganze Mittelbrustrücken mit dem angrenzenden Theil des Vorderbrustrückens , das Schildchen, die Mittelbrustseiten und die Mittelbrust dunkler oder heller bräunlich . Die Flügel wie in der Diagnose angegeben gebildet, das Randmal schwach braun. Die Beine behaart, die Tibien sammt den Tarsen oft graubraun oder dunkler. Die Schuppe wie bei dem Arbeiter tief und halb eiförmig ausgeschnitten. Der Hinterleib glänzend , mit dichten, gelblichen Haarborsten, die am Bauche etwas länger sind. Eine große Makel an der Basis des 2ten und das letzte Segment roth.

Das Männchen ist dem der Form. rufaähnlich aber glänzender , durch das ausgebuchtete Hinterhaupt und die nicht gefärbtenFlügel gleich zu unterscheiden. Die Borstenhaare kürzer als beim Weibchen und die niederliegende Behaarung etwas feiner. Die Augen wie bei dem Weibchen sehr zart haarig. Die Flügel wasserhell, ohne Spur einer bräunlichenFärbung , die Adern gelbbräunlich , das Randmal braun. Die Beine entweder bloßbräunlich mit dunkleren Hüften , oder die Schenkel faßt ganz blaßgelb , mit gelbbraunlicher Behaarung. Die Genitalien wie bei F. rufa . Die Ränder der Segmente in bestimmter Richtung gesehen glänzender und gleichfarbig.

Von dieser Art sind mir alle Geschlechter bekannt; sie legt kleine Haufen am Rande der Wälder an und zwar an sonnigen Plätzen . Das Material derselben besteht aus vertrockneten Grashalmen und ähnlichen kleinen Pflanzenpartikeln. Bis jetzt hat sie sich nur zu Stollberg bei Aachen gefunden.

Formica exsecta (the narrow-headed ant or excised wood ant) is a species of ant found from Western Europe to Asia.

A rare formicine ant with a deeply excised head, F. exsecta forms small mounds up to around a foot in height consisting of much finer material than that used by "true" wood ants of the F. rufa group.

An interesting feature of F. exsecta is that it occurs in two distinct social forms: either a monogyne form where the colony has a single egg-laying queen, or a polygyne form where many egg-laying queens are part of the same colony.

F. exsecta is placed in the Coptoformica subgenus within the genus and is closely related to Formica exsectoides, an American species. Both species may form vast colony networks. The largest known polydomous system of F. exsecta consists of 3,350 nests dispersed over about 22 ha in Transylvania, Romania.

In Great Britain, F. exsecta can be found only in a few scattered heathland locations in South West England — principally Chudleigh Knighton Heath and nearby Bovey Heath, which are both managed by the Devon Wildlife Trust, and in the central Scottish Highlands (including Rannoch Moor). A population centre previously existed in the New Forest, and such eminent myrmecologists as Horace Donisthorpe recorded this species there and in Parkhurst Forest on the Isle of Wight in the last century, but this seems to have declined considerably over the past few decades, and recent searches in such locations have failed to find any trace of colonies. The narrow-headed ant is currently one of the target species in the Back from the Brink project, which aims to extend its range in England.

F. exsecta has also been found in forests in Sweden, Finland, Germany, Tibet, and China.