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Formicidae
Formica exsecta Nylander, 1846
EOL Text
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).
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | Copyright Wildscreen 2003-2008 |
Source | http://www.arkive.org/narrow-headed-ant/formica-exsecta/ |
The following is a representative barcode sequence, the centroid of all available sequences for this species.
There are 2 barcode sequences available from BOLD and GenBank.
Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.
See the BOLD taxonomy browser for more complete information about this specimen and other sequences.
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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).
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | Copyright Wildscreen 2003-2008 |
Source | http://www.arkive.org/narrow-headed-ant/formica-exsecta/ |
Barcode of Life Data Systems (BOLDS) Stats
Public Records: 2
Specimens with Barcodes: 8
Species With Barcodes: 1
Mostly alpine grasslands
License | http://creativecommons.org/licenses/by-nc-sa/1.0/ |
Rights holder/Author | AntWeb |
Source | http://www.antweb.org/description.do?genus=formica&name=exsecta&rank=species |
Classified as Endangered in Great Britain (3).
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | Copyright Wildscreen 2003-2008 |
Source | http://www.arkive.org/narrow-headed-ant/formica-exsecta/ |
50 . Formica exsecta Nylander HNS , 1846 Figs. 201, 202,208,212, 214, 217.
Formica exsecta Nylander HNS , 1846a: 909.
Worker. Bicoloured with gaster dark brown, rest of body reddish with varying amount of dark colour on head and promesonotum. Head strongly excised posteriorly; maxillary palps 6 segmented, long as half head length. Scale strongly emarginate. Eyes with very distinct erect hairs which are normally abundant. Body pilosity variable - erect hairs on all gaster tergites, on clypeus and on dorsum of head, sometimes also on occipital margins. Clypeus not impressed. Length: 4.5-7.5 mm.
Figs. 197-200. Formica rufibarbis Fabr HNS . - 197: worker in profile; 198: head of queen in dorsal view; 199: queen in profile; 200: head of male in dorsal view: Scale: 1 mm.
Queen . As worker, head normally somewhat darker and promesonotum more or less dark brown. Head pilosity very variable but eyes always distinctly haired. Length: 7.5-9.5 mm.
Male. Dark brownish black, appendages yellowish to brown. Head broadly emarginate, scale excised. Eyes with distinct but sparse hairs. Maxillary palps 6 segmented, long. Length: 6.2-9.0 mm.
Distribution. Throughout Denmark and Fennoscandia, very common. - Local in Southwest England and Scottish Highlands. - Range: Central Spain to Urals, Appenines to extreme north of Europe.
Biology. This is an active aggressive species building mounds of leaf litter in open woodland, moorland and rough pasture. On disturbance the ants swarm out and bite vigorously. Nests may contain a thousand or more workers with more than one queen. They are often grouped with amicable interchange of workers between each. F. exsecta HNS is mainly aphidicolous tending aphids on Juniperus, Picea and other trees but is also predaceous. Colonies extend by nest splitting but single queens also start colonies by securing acceptance in nests of Formica lemani HNS or F. fusca HNS . Alatae occur in July.
License | Public Domain |
Rights holder/Author | No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation. |
Source | http://treatment.plazi.org/id/FD063E2318DFD0F90015B7C1EEA3D3BA |
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).
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | Copyright Wildscreen 2003-2008 |
Source | http://www.arkive.org/narrow-headed-ant/formica-exsecta/ |
8. Form. exsecta HNS .
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 HNS , 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. rufa HNS ähnlich 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 HNS . 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.
License | Public Domain |
Rights holder/Author | No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation. |
Source | http://treatment.plazi.org/id/920EE9C917109E414A93D23F02853535 |
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).
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | Copyright Wildscreen 2003-2008 |
Source | http://www.arkive.org/narrow-headed-ant/formica-exsecta/ |