leptothorax acervorum is a small brown to yellow ant in the subfamily myrmicinae .

it was first described by johan christian fabricius in 1793 .

l. acervorum is vastly distributed across the globe , most commonly found in the coniferous forests of central , western and northern europe .

the morphology of l. acervorum is extremely similar to that of other leptothorax ants .

the difference arises in the two-toned appearance of l. acervorum , with the head and metasoma being darker than the mesosoma segment of the body , and hair across its body .

following bergmann 's rule — unusually , for ectothermic animals — body size increases with latitude .

leptothorax acervorum

she is a important hostant for the slavekeepingant harpagoxenus sublaevis and the three workerless leptothorax - species leptothorax goesswaldi , leptothorax kutteri and leptothorax pacis .
senior synonym of leptothorax lacteipennis : nylander , 1846a pdf : 936 ; of leptothorax kamtshaticus : kupyanskaya , 1986b : 96 ; of leptothorax acervorum orientalis : kupyanskaya , 1990a : 137 ; of leptothorax nigrescens , leptothorax superus : radchenko , 1995a : 23 .
mating frequency and mating system of the polygynous ant , leptothorax acervorum . - pubmed - ncbi
queen - worker ratios in high skew and low skew populations of the ant leptothorax acervorum .
senior synonym of leptothorax acervorum vandeli : casevitz - weulersse & galkowski , 2009 pdf : 488 .
kurtjacobsen’s leptothorax acervorum journal - including lots of pictures and videos . - the ant farm and myrmecology forum
key words : leptothorax acervorum , functional monogyny , mating behavior , intranidal mated offspring hibernation , ecology .
the measured values are by no means unusual among related leptothorax species . leptothorax athabasca is a bit larger than the european leptothorax muscorum and the syntopic leptothorax retractus , but smaller than leptothorax acervorum and the north american leptothorax “sp . b” sensu heinze & buschinger ( 1987 ) , heinze ( 1989b ) and loiselle & al . ( 1990 ) .
a misunderstood instance of teratology in belgian leptothorax acervorum ( fabricius , 1793 ) ( hymenoptera , formicidae ) .
this taxon is not in use as it is currently considered to be a junior synonym of leptothorax acervorum .
kamtshaticus . leptothorax ( mychothorax ) acervorum subsp . kamtshaticus ruzsky , 1920 : 77 ( w . ) russia . junior synonym of acervorum : kupyanskaya , 1986b : 96 .
hammond rl , bourke af , bruford mw . mating frequency and mating system of the polygynous ant , leptothorax acervorum .
in deze video laat ik mijn leptothorax acervorum ( behaarde slankmier ) kolonie zien . mail : mierenkopen @ gmail . com .
leptothorax mayr , 1855 : 431 . type - species : formica acervorum , by subsequent designation of bingham , 1903 : 214 .
intra - and inter - nest variation in mitochondrial dna in the polygynous ant leptothorax acervorum ( hymenoptera ; formicidae ) . insectes soc
a misunderstood instance of teratology in belgian leptothorax acervorum ( fabricius , 1793 ) ( hymenoptera , formicidae ) . | vankerkhoven francois - urltoken
afg ( 1995a ) geographical variation in the social and genetic structure of the ant , leptothorax acervorum - heinze , lipski , et al .
bourke afg ( 1995 ) further evidence of lack of pheromonal inhibition among queens of the ant leptothorax acervorum . ethology 101 : 46 - 50 .
queen behaviour , reproduction and egg cannibalism in multiple - queen colonies of the ant leptothorax acervorum . anim behav 42 : 295 - afg - 1991
rüppell o ( 2001 ) sex allocation ratios in the facultatively polygynous ant , leptothorax acervorum . behav ecol sociobiol 50 : 270–274 - heinze , hartmann
combination in leptothorax : mayr , 1855 pdf : 436 ; in leptothorax ( mychothorax ) : ruzsky , 1904a pdf : 288 .
in britain no parasitic ant species is known to be associated with l . acervorum .
bourke afg ( 1993 ) lack of experimental evidence for pheromonal inhibition of reproduction among queens in the ant leptothorax acervorum . animal behaviour 45 : 501 - 509 .
reproductive status and skew of pyrenean ( py ) and inner iberian colonies of l . acervorum
leptothorax acervorum is the only species remaining in leptothorax after the other four british species were moved to temnothorax ( bolton 2003 ) . l . acervorum are small myrmicine ants with distinct propodeal spines and three - segmented antennal clubs . l . acervorum are larger than the british temnothorax species and can be distinguished by an 11 - segmented antenna in the females ( 12 in males ) ; the temnothorax species have one extra funicular segment .
friend la , bourke afg ( 2012 ) absence of within - colony kin discrimination in a multiple - queen ant , leptothorax acervorum . ethology 118 : 1182 - 1190 .
hammond rl , bourke afg , bruford mw ( 2001 ) mating frequency and mating system of the polygynous ant , leptothorax acervorum . molecular ecology 10 : 2719 - 2728 .
bourke afg ( 1991 ) queen behaviour , reproduction and egg - cannibalism in multiple - queen colonies of the ant leptothorax acervorum . animal behaviour 42 : 295 - 310 .
mychothorax ruzsky , 1904a : 288 . type - species : formica acervorum , by original designation .
results of analysis of molecular variance ( amova ) by pairwise comparison between regions for l . acervorum
the flights of l . acervorum males and gynes usually occur in mid - summer and are inconspicuous .
genetic diversity indices and neutrality tests for mtdna sequences of l . acervorum in sw - and c - europe
heinze j , lipski n , hölldobler b , bourke afg ( 1995 ) geographical variation in the social and genetic structure of the ant , leptothorax acervorum . zoology 98 : 127 - 135 .
[ later misspelled as leptothorax superbus by ruzsky , 1936 pdf : 94 . ] .
the above specimen data are provided by antweb . please see leptothorax athabasca for further details
mychothorax junior synonym of leptothorax : smith , m . r . 1950 : 29 .
the above specimen data are provided by antweb . please see leptothorax crassipilis for further details
material of the nomen nudum leptothorax melanocephala referred here by mayr , 1855 pdf : 411 .
mychothorax subgenus of leptothorax : ruzsky , 1905b : 609 ; emery , 1915g : 24 .
[ leptothorax and mychothorax share the same type - species , synonymy is therefore absolute . ]
leptothorax acervorum are small ants that can resist extremely cold temperatures and live in regions where temperatures can reach - 40°c in winter . they live in small colonies made of about 200 workers and a few queens .
19 . bernadou a , römermann c , gratiashvili n , heinze j ( 2016 ) body size but not colony size increases with altitude in the holarctic ant , leptothorax acervorum . ecol entomol 41 : 733 - 736
63 . trettin j , seyferth t , heinze j ( 2014 ) behavioral plasticity in ant queens : environmental manipulation induces aggression among normally peaceful queens in the socially polymorphic ant leptothorax acervorum . plos one 9 : e95153
the origin of workerless parasites in leptothorax ( s . str . ) ( hymenoptera : formicidae )
leptothorax acervorum is a non - aggressive ant which avoids most combats with other ants . the workers forage singly , predating small insects or scavenging insect corpses . they are suitable to co - house them with other ants .
result of general linear model tests for the second experiment : the effect of manipulation on different life - history traits , whilst accounting for species ( leptothorax acervorum and l . muscorum ) and habitat ( abensberg and innichen )
this 5x photo of an ant ( leptothorax acervorum ) carrying its larva received an honorable mention in the 2014 nikon small world photomicrophotography competition , which recognizes excellence in photography with the optical microscope , and was taken by . . .
results of general linear model tests for the first experiment : the effect of parasite manipulation on different life - history traits , whilst accounting for habitat heterogeneity ( experimental blocks ) and host species ( leptothorax acervorum and l . muscorum )
heinze and gratiashvili ( 2015 ) - a phylogenetic analysis suggests that functional monogyny evolved convergently in several lineages of leptothorax . reproductive skew thus appears to be a labile trait . this is made particularly obvious by the existence of both functionally monogynous and polygynous populations of leptothorax acervorum ( heinze et al . 1995 ; gill et al . 2009 ) .
citation : trettin j , seyferth t , heinze j ( 2014 ) behavioral plasticity in ant queens : environmental manipulation induces aggression among normally peaceful queens in the socially polymorphic ant leptothorax acervorum . plos one 9 ( 4 ) : e95153 . urltoken
remarks on the occurrence of leptothorax nylanderi ( först . ) ( hymenoptera , formicidae ) in poland and its taxonomy
diethe ortius , and jürgen heinze , “dynamics and consequences of hierarchy formation in the ant leptothorax sp . a , ”
mackay , w . p . 2000 . a review of the new world ants of the subgenus myrafant , ( genus leptothorax ) ( hymenoptera : formicidae ) . sociobiology 36 : 265 - 444 ( page 267 , leptothorax in myrmicinae , formicoxenini )
sur le polymorphisme social de la fourmi leptothorax nylanderi ( förster ) . ii . − activité des ouvrières et déterminisme des castes
j . heinze , and n . gratiashvili , “high skew in the caucasus : functional monogyny in the ant leptothorax scamni , ”
the color of l . athabasca gynes and workers is evenly dark brown , similar to l . acervorum ( but lacking the lighter areas on the body of that species ) , lighter than in the sympatric leptothorax “sp . b” , and darker than in l . retractus from the same site .
this stacking image of the ant , leptothorax acervorum carrying won honorable mention in the 2014 nikon small world competition . leptothorax acervorum is a model system used to study ant colonies with multiple queens . female reproductives leave the nest and mate with males from other nests . a successful mated queen will typically follow one of two options . she will drop to the ground near her home nest and hope to be “adopted” . adopted queens are carried into the nest by workers . alternatively the a mated queen can disperse to initiate a new colony . the success rate of new colony initiation is low .
sculpture and pilosity are quite similar to other north american species of leptothorax . some negative characters may be helpful for identification , though :
j . ürgen heinze , “the origin of workerless parasites in leptothorax ( s . str . ) ( hymenoptera : formicidae ) , ”
j . heinze , and b . oberstadt , “worker age , size and social status in queenless colonies of the ant leptothorax gredleri , ”
leptothorax retractus is characterized by a small but clearly visible notch in the anterior margin of the clypeus . this notch lacks in l . athabasca .
snelling , r . r . 1986 . new synonymy in caribbean ants of the genus leptothorax ( hymenoptera : formicidae ) . proc . entomol . soc . wash . 88 : 154 - 156 ( page 154 , leptothorax senior synonym of macromischa ( and its junior synonyms antillaemyrmex and croesomyrmex ) )
leptothorax acervorum colonies were more abundant and larger than l . muscorum colonies in innichen . leptothorax acervorum colonies also contained more queens and exhibited higher total production , but only in innichen . in abensberg , the other host species , l . muscorum , often did better ; for example , it had higher per capita productivity than l . acervorum . this result can be explained by the colder climate of innichen , which is approximately 800 m higher than abensberg , as expected from previous studies of ectotherms in general and ants in particular . in addition , the body size of l . acervorum workers is larger than that of the other host species . colonies in innichen did not contain more queens per se , but l . acervorum , which was more abundant than l . muscorum in innichen , contained , in general , more queens , fitting the expected increase in polygyny in harsher habitats . finally , the average colony size was more than double in innichen compared with abensberg . it should be noted that , in a previous study comparing two populations of l . acervorum , such a climate - dependent difference in colony size was not found ( heinze et al . , 2003 ) . in any case , only a large - scale documentation of colony sizes along the whole geographical range ( and not focusing only on two populations as performed here and in the former study ) will provide strong support for this temperature–size pattern .
propodeal spine length ( psl , gusten & al . 2006 ) has not been measured in other species of leptothorax . the propodeal spine index ( psi ; epinotal spine index in buschinger 1966 ) can be compared among a few species . in l . athabasca gynes it is 1 . 3 - 1 . 6 ; in l . acervorum ( europe ) 1 . 87 ± 0 . 06 ( buschinger 1966 ) ; in l . muscorum ( europe ) 1 . 73 ± 0 . 09 ( buschinger 1966 ) ; in leptothorax gredleri ( europe ) 1 . 48 ± 0 . 06 ( buschinger 1966 ) ; in leptothorax scamni ( caucasus and northern turkey ) c . 2 . 0 ( heinze & al . 1993 ) ; in leptothorax pocahontas ( canada ) 1 . 7 - 1 . 8 ( buschinger 1979 ) ; and in leptothorax faberi ( canada ) 1 . 5 - 1 . 8 ( buschinger 1983 ) .
smith , m . r . 1950a . on the status of leptothorax mayr and some of its subgenera . psyche ( camb . ) 57 : 29 - 30 ( page 29 , leptothorax senior synonym of mychothorax ; [ both have the same type - species , synonymy is therefore absolute ] . )
s . foitzik , m . stratz , and j . heinze , “ecology , life history and resource allocation in the ant , leptothorax nylanderi , ”
the aims of this study , therefore , were ( i ) to map the distribution of the two social phenotypes of l . acervorum in inner iberian mountains and pyrenees , ( ii ) to analyse the micro - evolutionary history of the two social forms using genetic markers , and ( iii ) to infer the population history of l . acervorum in sw - europe in a broader phylogeographic context .
leptothorax sp . c ( sensu heinze & buschinger 1987 , heinze 1989b and loiselle & al . 1990 ) , supposed to be the host species of l . pocahontas , is much lighter in coloration . higgins ( year unknown ) suggested that leptothorax sp . c from jasper np is identical to leptothorax muscorum var . septentrionalis wheeler , 1917 , though this taxon still is considered a junior synonym of l . muscorum according to urltoken and bolton & al . ( 2007 ) .
leptothorax senior synonym of mychothorax : smith , m . r . 1950 : 29 [ both have the same type - species , synonymy is therefore absolute ] .
intrapopulation nest clusters of maternal mtdna lineages in the polygynous ant leptothorax mec _ 1394 . fm page 2727 tuesday , october 23 , 2001 6 : 43 pm 2728
second experiment . number of queens according to treatment ( parasite - free , sympatric parasite and allopatric parasite plots ) ( a ) and species ( leptothorax acervorum and l . muscorum ) and habitat ( abensberg and innichen ) ( b ) . total production according to treatment ( c ) and species and habitat ( d ) . means ± standard error are presented .
39 . heinze j , gratiashvili n ( 2015 ) high skew in the caucasus : functional monogyny in the ant leptothorax scamni . insectes soc 62 : 385 - 392
mean pairwise migration rates for iberian populations of l . acervorum ( with error bars indicating 95 % cis ) . rates are given as immigration and emigration separately , with respect to pyrenees ( py i and ii )
cantiacus – you know more about this species ? by the way , what ant is it on your avatar – it could actually look a bit like leptothorax or similar .
bolton , b . 2003 . synopsis and classification of formicidae . mem . am . entomol . inst . 71 : 370pp ( page 247 , leptothorax in myrmicinae , formicoxenini )
gt dinucleotide repeat polymorphisms in a polygynous ant , leptothorax spinosior and their use for measurement of relatedness . naturwissenschaften 80 : 179–181 - hamaguchi , itô , et al . - 1993
leptothorax acervorum is widely distributed throughout england , wales , scotland and ireland . it is relatively abundant throughout its range from cornwall to northern scotland and can be found quite readily in most areas , apart from extreme urban and intensively agricultural sites . the species is more commonly associated with inland rather than coastal sites . this species occurs from arctic scandinavia south to southern europe , and across asia to japan .
hey , i have wondered where to buy springtails in europe for a while . they seem like awsome food for temnothorax / leptothorax colonies . where abouts do you get them ? thanks .
fabricius ' s ( 1793 ) description is at . nylander ( 1846a : 936 ) gave a full description , as myrmica acervorum , this is at . bondroit ( 1918 : 112 ) gave a fuller description , this is at .
scientists have asked , “why has sociality evolved many times in the hymenoptera . one answer proposes that genetic relatedness is key . male hymenoptera have only one set of chromosomes . every female progeny of the male with a single queen will be on average 3 / 4 genetically identical . the half of their genes that come from the male are 100 % identical . the half of the genes that come from the queen are 50 % identical . thus , sociality may be genetically favorable because workers would benefit more from raising sisters ( which are 3 / 4 identical ) than raising their own offspring which would share only 50 % identity . when societies such as leptothorax acervorum have multiple queens , this answer no longer applies because the relatedness of sisters is less than half on average . leptothorax acervorum is studied as a model of a society with low relatedness of workes .
the flat and slender mesosoma in the female castes probably represents an adaptation to life in narrow rock crevices . this character corresponds well with the fact that practically all other leptothorax species both in europe and in north america preferably are nesting in dead wood or bark ( leptothorax acervorum in some places also in rock crevices ) , where nest entrances and galleries usually are tubular . the new species seems to have an extremely limited range as far as is known , a phenomenon , however , that appears to be not unusual among the formicoxenini . intensive search in alberta did not reveal any other site where l . athabasca would occur .
l ' essaimage de quelques fourmis leptothorax : rôles de l ' éclairement et de divers autres facteurs . effet sur l ' isolement reproductif et la répartition géographique . 2e partie , suite et fin
mayr , g . 1861 . die europäischen formiciden . nach der analytischen methode bearbeitet . wien : c . gerolds sohn , 80 pp . ( page 57 , leptothorax in myrmicinae [ myrmicidae ] )
allies ab , bourke afg , franks nr ( 1986 ) propaganda substances in the cuckoo ant leptothorax kutteri and the slave - maker harpagoxenus sublaevis . journal of chemical ecology 12 : 1285 - 1293 .
few studies have reported intraspecific tests within ant species . there was no support for the prediction of transactional models of a positive association between skew and relatedness in myrmica tahoensis ( evans , 1995 ) , and data from formica fusca agrees better with predictions of compromise models ( hannonen mt and sundström l , personal communication ) . in contrast , bourke et al . ( 1997 ) provided supportive data for transactional models by comparing two populations of leptothorax acervorum .
bolton , b . 1994 . identification guide to the ant genera of the world . cambridge , mass . : harvard university press , 222 pp . ( page 105 , leptothorax in myrmicinae , formicoxenini )
kusnezov , n . 1964 [ 1963 ] . zoogeografía de las hormigas en sudamérica . acta zool . lilloana 19 : 25 - 186 ( page 57 , leptothorax in myrmicinae , myrmicini ( anachronism ) )
41 . bernadou a , ruther j , heinze j ( 2015 ) avoid mistakes when choosing a new home : nest choice and adoption of leptothorax ant queens . j insect physiol 79 : 88 - 95
supplementary material tab . s1 . collecting sites of leptothorax samples , genbank accession numbers of gene sequences , and deposition of voucher specimens [ to be completed in final version ] . ( doc 65 kb )
rüppell o , schäffler l , hölldobler b ( 2002 ) lack of plasticity in the behaviour of queens of the ant leptothorax rugatulus emery ( formicidae : hymenoptera ) . j insect behav 15 : 447–454 .
the evolutionary origin of workerless parasitic ants parasitizing colonies of leptothorax ( s . str . ) is investigated using data on morphology , chromosome number , and allozyme phenotype of both social parasites and their hosts . of the three previously proposed pathways , the evolution of workerless parasites from guest ants or slave - makers is unlikely , at least according to a phenogram obtained by upgma clustering of nei ' s similarities based on seven enzymes , lntraspecific evolution of the workerless parasites doronomyrmex goesswaldi , d . kutteri , and d . pacis from their common host , leptothorax acervorum cannot be excluded with the present data . the workerless parasite l . paraxenus , however , clearly differs from its host , l . cf . canadensis , in morphology and biochemistry , and most probably did not evolve from the latter species . it is proposed to synonymize doronomyrmex under leptothorax ( s . str . ) .
frequency of egg eating ( observations per queen during the total observation period , median , quartiles , range ) in colonies of the ant leptothorax acervorum from the low - skew population in nürnberger reichswald . individual colonies were subjected to different types of stress ( food reduction f , worker reduction w , or both fw ) or left unmanipulated ( control c ) in two different seasons ( july , i , and september , ii ) . outliers are indicated as circles .
wheeler , w . m . 1910b . ants : their structure , development and behavior . new york : columbia university press , xxv + 663 pp . ( page 139 , leptothorax in myrmicinae , myrmicini )
frequency of queens groomed by workers ( observations per queen and worker during the total observation period , median , quartiles , range ) of the ant leptothorax acervorum from the low - skew population in nürnberger reichswald . individual colonies were subjected to different types of stress ( food reduction f , worker reduction w , or both fw ) or left unmanipulated ( control c ) in two different seasons ( july , i , and september , ii ) . outliers are indicated as circles .
forel , a . 1895b . a fauna das formigas do brazil . bol . mus . para . hist . nat . ethnogr . 1 : 89 - 139 ( page 125 , leptothorax in myrmicinae , myrmicini )
forel , a . 1917 . cadre synoptique actuel de la faune universelle des fourmis . bull . soc . vaudoise sci . nat . 51 : 229 - 253 ( page 244 , leptothorax in myrmicinae , leptothoracini )
emery , c . ; forel , a . 1879 . catalogue des formicides d ' europe . mitt . schweiz . entomol . ges . 5 : 441 - 481 ( page 458 , leptothorax in myrmicinae [ myrmicidae ] )
frequency of trophallaxis , i . e . , food exchange , among queens ( observations per queen during the total observation period , median , quartiles , range ) of the ant leptothorax acervorum from the low - skew population in nürnberger reichswald . individual colonies were subjected to different types of stress ( food reduction f , worker reduction w , or both fw ) or left unmanipulated ( control c ) in two different seasons ( july , i , and september , ii ) . outliers are indicated as circles .
we investigated whether queens from a low - skew population of the ant leptothorax acervorum adjust their behavior towards nestmate queens and the partitioning of reproduction in response to experimentally changed conditions . our data show that experimental manipulation , in particular the reduction of worker numbers , provoked fighting and dominance interactions similar in quality and quantity to those previously observed in high - skew populations of this and other leptothorax species . though the absolute number of queen - queen attacks was low , few and infrequent interactions may suffice to establish clear social and reproductive rank orders among ants ( e . g . , [ 31 ] ) . food reduction alone did not lead to an increase in aggression but resulted in a higher frequency of food begging and food exchange among queens .
bolton , b . 1982 . afrotropical species of the myrmecine ant genera cardiocondyla , leptothorax , melissotarsus , messor and cataulacus ( formicidae ) . bulletin of the british museum ( natural history ) . entomology , 46 : 307 - 370 ( page 319 , leptothorax senior synonym of dichothorax , mychothorax , myrafant ( and its junior synonym icothorax ) , myrmammophilus , nesomyrmex ( and its junior synonyms caulomyrma , goniothorax ( junior homonym ) and limnomyrmex ) , temnothorqax , tetramyrma )
bingham , c . t . 1903 . the fauna of british india , including ceylon and burma . hymenoptera , vol . ii . ants and cuckoo - wasps . london : taylor and francis , 506 pp . ( page 214 , type - species : formica acervorum , by subsequent designatio )
wheeler , w . m . 1915i [ 1914 ] . the ants of the baltic amber . schr . phys . - ökon . ges . königsb . 55 : 1 - 142 ( page 63 , leptothorax in myrmicinae , myrmicini )
buschinger , a . and a . schulz . 2008 . leptothorax athabasca sp . n . ( hymenoptera : formicidae ) from alberta , canada , an ant with an apparently restricted range . myrmecologische nachrichten . 11 : 243 - 248 . pdf
arnold , g . 1916 . a monograph of the formicidae of south africa . part ii . ponerinae , dorylinae . ann . s . afr . mus . 14 : 159 - 270 ( page 257 , leptothorax in myrmicinae , leptothoracini )
dalla torre , k . w . von . 1893 . catalogus hymenopterorum hucusque descriptorum systematicus et synonymicus . vol . 7 . formicidae ( heterogyna ) . leipzig : w . engelmann , 289 pp . ( page 122 , leptothorax in myrmicinae )
emery , c . 1877b . saggio di un ordinamento naturale dei mirmicidei , e considerazioni sulla filogenesi delle formiche . bull . soc . entomol . ital . 9 : 67 - 83 ( page 81 , leptothorax in myrmicidae , myrmicidae ` )
leptothorax rugatulus is widespread in the western united states ( creighton , 1950 ) . in our study area ( southern arizona and new mexico ) , it mainly nests under stones or in rock crevices in mixed coniferous forests on mountain ranges . to investigate the pattern of reproduction among leptothorax rugatulus queens , two experimental groups of colonies were established in the laboratory : unmanipulated colonies and artificially mixed groups . both groups comprised colonies with only macrogynes , only microgynes , or both ( mixed colonies ) .
workers of l . acervorum forage singly and unobtrusively , mainly in search of carrion , although they may tackle very small and weak invertebrates . homoptera are not actively tended for their honeydew . they forage over the ground and rock surface or amongst fallen dead wood and leaf litter and can often be found taking scraps of food , dead corpses and nest rubbish from around the colonies of other much larger ants such as formica species . they are rarely bothered by the larger ants due to their stealthy and appeasing nature and l . acervorum nests can also often be found in close association with those of other species .
supported by deutsche forschungsgemeinschaft ( he1623 / 30 ) and shota rustaveli national science foundation ( 04 / 24 ) . we thank abel bernadou and nina spitzenpfeil for providing sequences of l . gredleri and andreas trindl and jürgen trettin for sequences of l . acervorum . three referees made helpful comments on the manuscript .
ideally we should also have performed the opposite experiment , i . e . , trying to induce queen tolerance in colonies from high skew populations of l . acervorum by adding workers or overfeeding the colonies . however , documenting the complete disappearance of a rare behavioral trait is more difficult than documenting its induction . furthermore , queen aggressiveness and reproductive skew appear to vary to some extent among natural colonies of high skew populations of l . acervorum and related species , and not in all studied colonies were queens seen to engage in aggressive interactions [ 19 ] , [ 28 ] , [ 31 ] , [ 49 ] .
emery , c . 1895l . die gattung dorylus fab . und die systematische eintheilung der formiciden . zool . jahrb . abt . syst . geogr . biol . tiere 8 : 685 - 778 ( page 769 , leptothorax in myrmicinae , myrmicini )
leptothorax pocahontas has long , tapering hairs and , in the typical case , a smooth and shiny surface ( however ,
dull
gynes with shorter hairs have been found and provisionally attributed to this species , cf . buschinger & heinze 1993 ) .
heinze , j . and n . gratiashvili . 2015 . high skew in the caucasus : functional monogyny in the ant leptothorax scamni . insectes sociaux . 62 : 385 - 392 . doi : 10 . 1007 / s00040 - 015 - 0415 - 5
buschinger & schulz ( 2008 ) - the habitat is the river bank that sometimes is evidently flooded . a horizontally split , schist - like sandstone cliff is exposed there . the ants were exclusively found in rock crevices , whereas above the flood line a number of related species of leptothorax were dwelling dead wood , or a layer of conifer needles and debris beneath small flat rocks . mainly leptothorax retractus could be found there . close to the river and in the collecting site the coniferous forest was comparatively open .
heinze , j . 1998 (
1995
) . the origin of workerless parasites in leptothorax ( s . str . ) ( hymenoptera : formicidae ) . psyche ( cambridge ) 102 : 195 - 214 . [ 1998 - 03 - 27 ] pdf
supplementary material fig . s1 . close up of the nest of leptothorax scamni under spruce bark . the arrow points to the nest cavity with a cluster of larvae . the white material above and below the nest is dried resin . ( jpeg 173 kb )
haplotype network of l . acervorum from sw - europe , germany ( d ) and england ( e ) . populations and geographic regions are labelled by different colours . the size of haplotypes is proportional to the number of individuals ( see concentric circles ) and each line between haplotypes represents a single mutational step . included are two extreme divergent haplotypes that differ by 31 ( 23 + 8 ) ( py i ) and 26 ( fr iii ) mutations and a reference sequence of leptothorax kutteri ( lk ) that differ by 32 ( 24 + 8 ) mutations from the core network , respectively
. . . queen : worker ratios of 1 : 4 or more are commonly observed in high - skew populations of l . acervorum ( e . g . , see figure s1 in trettin et al . 2014 ) . for example , the ratio varied from 1 : 8 to 1 : 4 queens per worker in l . acervorum colonies in japan ( ito 2005 ) , and queen : worker ratios ≥1 : 4 were observed in 25 of 50 colonies from spain ( felke 1999 ; felke and buschinger 1999 ) . therefore , the ratio employed in our study is biologically realistic and resembles natural conditions observed in high - skew popu - lations . . . .
buschinger & schulz ( 2008 ) - a detailed differential diagnosis cannot be provided because of the desolate condition of leptothorax taxonomy in north america . a comparison is possible only with a few well - known species and with the sympatric forms in the vicinity of the type locality .
ashmead , w . h . 1905c . a skeleton of a new arrangement of the families , subfamilies , tribes and genera of the ants , or the superfamily formicoidea . can . entomol . 37 : 381 - 384 ( page 383 , leptothorax in myrmicinae , stenammini )
angelika oppelt , fernanda c . humann , marion fuessl , sergio v . azevedo , david s . marco antonio , juergen heinze , and klaus hartfelder , “suppression subtractive hybridization analysis reveals expression of conserved and novel genes in male accessory glands of the ant leptothorax gredleri , ”
emery , c . 1914e . intorno alla classificazione dei myrmicinae . rend . sess . r . accad . sci . ist . bologna cl . sci . fis . ( n . s . ) 18 : 29 - 42 ( page 42 , leptothorax in myrmicinae , leptothoracini )
total production was higher in allopatric parasite plots than in parasite - free plots ( least - significant difference post hoc test ; fig . 3c ) . species and habitat interacted again to affect total production : l . acervorum had a higher total production in innichen , whereas l . muscorum did better in abensberg ( significant habitat × species ' interaction ; fig . 3d ) . habitat and species as main effects were not significant . per capita productivity differed between species ( higher in l . muscorum ) and between habitats ( higher in abensberg ) . the treatment ' s main influence was through a treatment × habitat interaction : allopatric parasite plots included more productive colonies than parasite - free plots in abensberg , but treatment had little effect in innichen ( fig . 4a ) . leptothorax muscorum colonies showed higher per capita productivity in abensberg than in innichen , whereas l . acervorum colony per capita productivity did not differ between the habitats ( significant habitat × species ' interaction ; fig . 4b ) .
we investigated sex allocation in a central european population of the facultatively polygynous ant leptothorax acervorum . the population - wide sex ratio was found to be quite balanced , with a proportional investment in female sexuals of 0 . 49 . sex allocation varied considerably between colonies , resulting in split sex ratios . the productivity of colonies was negatively correlated with queen number and positively with colony size . in contrast , the sex ratio ( proportional investment in female sexuals ) was neither correlated with queen number , colony size , nor total sexual production , but with worker relatedness . the uncoupling of the genetic colony structure and queen number presumably results from frequent queen turnover and colony splitting .
in social insects , workers of different morphological castes and age are known to act differently . yet , it is unclear how body size and ovarian development influence worker personalities ( i . e . consistent behavioral variation ) and task allocation in similar aged ant workers of monomorphic species . behavioral variation is thought to be a key element of division of labor , but few studies have linked worker personality to task allocation . we investigated individual behavior in leptothorax acervorum ant workers at two time points during the first three months of their life and in two different settings . we observed worker behavior in the nest ( i . e . task allocation ) and in standardized aggression , exploration and brood care experiments ( i . e . personality ) and found behavioral repeatability in foraging and exploration . further , workers acted consistently across settings : workers with a more aggressive and exploratory personality type were more active in the nest . moreover , ovarian development was associated with worker personality and task allocation : older workers with well - developed ovaries foraged less , but were more aggressive and exploratory . in accordance with the typical age - polyethism of social insects , workers became more active and foraged more as they grew older . consequently , our study suggests that task allocation in leptothorax acervorum is not only influenced by ovarian development and age , but moreover by the personalities of its workers
multiple mating by queens ( polyandry ) and the occurrence of multiple queens in the same colony ( polygyny ) alter patterns of relatedness within societies of eusocial insects . this is predicted to influence kin - selected conflicts over reproduction . we investigated the mating system of a facultatively polygynous uk population of the ant leptothorax acervorum using up to six microsatellite loci . we estimated mating frequency by genotyping 79 dealate ( colony ) queens and the contents of their sperm receptacles and by detailed genetic analysis of 11 monogynous ( single - queen ) and nine polygynous colonies . results indicated that 95 % of queens were singly mated and 5 % of queens were doubly mated . the corrected population mean mating frequency was 1 . 06 . parentage analysis of adults and brood in 17 colonies ( 10 monogynous , 7 polygynous ) showed that female offspring attributable to each of 31 queens were full sisters , confirming that queens typically mate once . inbreeding coefficients , queen - mate relatedness of zero and the low incidence of diploid males provided evidence that l . acervorum sexuals mate entirely or almost entirely at random . males mated to queens in the same polygynous colony were not related to one another . our data also confirmed that polygynous colonies contain queens that are related on average and that their workers had a mixed maternity . we conclude that the mating system of l . acervorum involves queens that mate near nests with unrelated males and then seek readoption by those nests , and queens that mate in mating aggregations away from nests , also with unrelated males .
wheeler , w . m . 1922i . ants of the american museum congo expedition . a contribution to the myrmecology of africa . vii . keys to the genera and subgenera of ants . bull . am . mus . nat . hist . 45 : 631 - 710 ( page 664 , leptothorax in myrmicinae , leptothoracini )
the genus leptothorax may prove particularly important for tests of reproductive partitioning in ants because the relatively small colonies can be collected completely and maintained under seminatural condition in the laboratory ( buschinger , 1974a ) . leptothorax species exhibit a variety of social structures ( bourke and heinze , 1994 ; buschinger , 1974b ) , and remarkable data sets exist on various aspects of their biology ( e . g . , bourke et al . , 1997 ; herbers , 1990 ) . social diversity is also common within leptothorax species : in many cases single - queen ( monogynous ) and multiple - queen ( polygynous ) colonies coexist ( facultative polygyny ; bourke and franks , 1995 ) , which can be attributed to variation in ecological constraints on independent founding ( bourke and franks , 1995 ; herbers , 1993 ) . in some cases , variation in reproductive strategies has led to alternative queen morphs ( buschinger and heinze , 1992 ; heinze and tsuji , 1995 ; rüppell and heinze , 1999 ) .
supplementary material fig . s2 . timing of sexual activity ( median , quartiles of the proportion of active female sexuals ) in 16 colonies of the ant leptothorax scamni . colonies were removed from dark incubators at 15 °c and exposed to light and room temperature ( 19 °c ) at 8 : 00 . ( jpeg 23 kb )
loiselle , r . ; francouer , a . ; fischer , k . ; buschinger , a . 1990 . variations and taxonomic significance of the chromosome numbers in the nearctic species of the genus leptothorax ( s . s . ) ( formicidae : hymenoptera ) . caryologia 43 : 321 - 334 ( page 329 , see also )
mayr , g . 1865 . formicidae . in : reise der österreichischen fregatte
novara
um die erde in den jahren 1857 , 1858 , 1859 . zoologischer theil . bd . ii . abt . 1 . wien : k . gerold ' s sohn , 119 pp . ( page 20 , leptothorax in myrmicinae [ myrmicidae ] )
the disjunct distribution of several palearctic species has been widely shaped by the changes in climatic conditions during the quaternary . the observed genetic differentiation or reproductive isolation between extant populations may be the outcome of their contemporary geographic separation or reproductive incompatibility due to differences in phenotypic traits which have evolved in isolated refugia . in the boreal ant leptothorax acervorum , colonies from central and peripheral populations differ in social structure : colonies from central and northern europe may contain several equally reproductive queens ( facultative polygyny ) , while in colonies from peripheral populations in spain only one the most dominant of several queens lays eggs ( functional monogyny ) . by reconstructing the specie’s evolutionary and demographic history in southwestern europe we examine whether variation in social organization is associated with restricted gene flow between the two social forms .
there are several studies with ants that explore the relationship between latitude , altitude , and either colony size or body size ; kaspari & vargo ( 1995 ) , for example , found that extreme latitudes hold larger colonies and they explained this as a strategy to survive winter starvation . this explanation is known as the endurance hypothesis and found support from heinze et al . ( 2003 ) paper where worker size in leptothorax acervorum ( fabricius ) decreases but colony size increases with latitude . porter & hawkins ( 2001 ) however , questioned the application of these results to all social insects . we are unaware of papers studying jame ' s rule ( or bergmann ' s rule in an extended sense ) in social wasps despite that there are several species with wide altitudinal and latitudinal ranges .
our study demonstrates that queens of l . acervorum from low skew populations are able to react to changes in their social environment . in addition , it highlights the importance of queen - worker ratio for the adjustment of skew and the need for further studies to clarify its role and the role of other factors ( e . g . , egg cannibalism and habitat structure ) in the formation and maintenance of reproductive skew in insect societies .
analysis of genetic structure and relationship between and within iberian populations ( for microsatellites ) of l . acervorum . a unrooted neighbour - joining tree using nei ' s d a distance ( bootstrap values given as numbers close to nodes ) . b bayesian assignment analysis with all samples included ( individual membership proportions for k = 2 clusters ) . c bayesian assignment analysis without samples from py ii ( individual membership proportions for k = 4 clusters )
kin selection theory predicts that social insects should perform selfish manipulations as a function of colony genetic structure . we describe a novel mechanism by which this occurs . first , we use microsatellite analyses to show that , in a population of the ant leptothorax acervorum , workers ' relatedness asymmetry ( ratio of relatedness to females and relatedness to males ) is significantly higher in monogynous ( single–queen ) colonies than in polygynous ( multiple–queen ) colonies . workers rear mainly queens in monogynous colonies and males in polygynous colonies . therefore , split sex ratios in this population are correlated with workers ' relatedness asymmetry . together with significant female bias in the population numerical and investment sex ratios , this finding strongly supports kin–selection theory . second , by determining the primary sex ratio using microsatellite markers to sex eggs , we show that the ratio of male to female eggs is the same in both monogynous and polygynous colonies and equals the overall ratio of haploids ( males ) to diploids ( queens and workers ) among adults . in contrast to workers of species with selective destruction of male brood , l . acervorum workers therefore rear eggs randomly with respect to sex and must achieve their favoured sex ratios by selectively biasing the final caste ( queen or worker ) of developing females .
supplementary material fig . s5 . maximum likelihood consensus tree inferred from 523 bp sequences of the nuclear protein - coding gene longwave rhodopsin of leptothorax scamni and related species . figures at the nodes represent the percentage of replicate trees with a particular branching pattern . branches found in less than 50 % of 1000 bootstrap replicates are collapsed . ( pdf 9 kb )
kin selection theory predicts that social insects should perform selfish manipulations as a function of colony genetic structure . we describe a novel mechanism by which this occurs . first , we use microsatellite analyses to show that , in a population of the ant leptothorax acervorum , workers ' relatedness asymmetry ( ratio of relatedness to females and relatedness to males ) is significantly higher in monogynous ( single - queen ) colonies than in polygynous ( multiple - queen ) colonies . workers rear mainly queens in monogynous colonies and males in polygynous colonies . therefore , split sex ratios in this population are correlated with workers ' relatedness asymmetry . together with significant female bias in the population numerical and investment sex ratios , this finding strongly supports kin - selection theory . second , by determining the primary sex ratio using microsatellite markers to sex eggs , we show that the ratio of male to female eggs is the same in both monogynous and polygynous colonies and equals the overall ratio of haploids ( males ) to diploids ( queens and workers ) among adults . in contrast to workers of species with selective destruction of male brood , l . acervorum workers therefore rear eggs randomly with respect to sex and must achieve their favoured sex ratios by selectively biasing the final caste ( queen or worker ) of developing females .
supplementary material fig . s6 maximum likelihood consensus tree inferred from 361 bp sequences of the nuclear protein - coding gene elongation factor 1α - f1 of leptothorax scamni and related species . figures at the nodes represent the percentage of replicate trees with a particular branching pattern . branches found in less than 50 % of 1000 bootstrap replicates are collapsed . ( pdf 10 kb )
. . . unclear . if queens outbreed , and polygyny arises purely by the adoption of daughter queens , relatedness among queens within colonies is predicted to be negatively correlated with colony queen number ( = - = keller 1995 - = - ) . however , we found no relationship between queen number and the relatedness of queens in polygynous colonies of l . acervorum . likewise , heinze et al . ( 1995b ) found no relationship between queen numb . . .
as studies of reproductive distributions in field collected colonies of leptothorax have proven difficult due to potentially missing queens ( bourke et al . , 1997 ) , we investigated the reproductive distribution among cohabiting leptothorax rugatulus queens in a controlled laboratory experiment . specifically , the influence of intracolonial relatedness and body size of queens on reproductive partitioning were studied . we used unmanipulated colonies to investigate naturally occurring skew , as well as randomly assembled colonies to confront alien queens with each other and control for potential worker nepotism ( i . e . , to exclude the possibility that high skews resulted from workers nepotistically favoring the reproduction of their own mother ) . in addition , we investigated whether queens biased their reproduction toward one particular offspring type , relative to their nest - mate queens .
supplementary material fig . s4 . maximum likelihood consensus tree inferred from 646 bp sequences of the mitochondrial co i gene of leptothorax scamni and related species , including additional sequences of l . gredleri . figures at the nodes represent the percentage of replicate trees with a particular branching pattern . branches found in less than 50 % of 1000 bootstrap replicates are collapsed . ( pdf 15 kb )
in southern germany , the two sibling species meet close to the continental divide in the franconian alb , following the line neumarkt–berching–beilngries–ingolstadt–allershausen–mering ( fig . 1 ) . both species were found syntopically in four collecting sites in this area ( dietfurt , manching , eichstätt , berching ) and almost syntopically in velburg , where the two populations are divided by a field approximately 150 m in width . the ranges of both species therefore appear to overlap for at most 25 km . specimens collected further west in germany and other parts of europe were all t . nylanderi , whereas all material collected east and south - east of the contact zone were t . crassispinus . in some areas with apparently suitable habitat ( light forests with pines , beeches , and oaks ) close to the expected contact zone , neither t . crassispinus nor t . nylanderi could be found despite the presence of other ants , which regularly co - occur with the two sibling species in other sites ( e . g . leptothorax gredleri , leptothorax acervorum , temnothorax unifasciatus ) . furthermore , neither t . crassispinus nor t . nylanderi were found in deciduous forests at the northern border of the alps ( kempten , marktoberdorf , schongau , weilheim ; fig . 1 , see also appendix ) .
. . . ehaviour ( felke & buschinger 1999 ) , suggest that queens mate singly . furthermore , inbreeding coefficients not significantly different from zero are consistent with random mating ( stilleset al . 1991 ; = - = stille & stille 1993 - = - ; seppset al . 1995 ; bourkeset al . 1997 ; heinzeset al . 1995a , b , 2001 ) . field observations suggest that at least somesl . acervorum sexuals mate in large mating aggregations situated away from nests . . .
supplementary material fig . s3 . maximum likelihood consensus tree inferred from 820 bp sequences of the mitochondrial co i gene of leptothorax scamni and related species . figures at the nodes represent the percentage of replicate trees with a particular branching pattern . branches found in less than 50 % of 1000 bootstrap replicates are collapsed . functionally monogynous taxa are highlighted by red font . ( pdf 13 kb )
approximately 10 years ago , seifert ( 1995 , 1996 ) recognized that one of the most common ant species in deciduous forests in central europe actually comprises two morphologically very similar sibling species , temnothorax nylanderi [ formerly leptothorax ( myrafant ) nylanderi förster 1850 ; bolton , 2003 ] and temnothorax crassispinus ( karavajev 1926 ) [ previously leptothorax ( myrafant ) crassispinus ; bolton , 2003 ] . these species probably originated from populations of a common ancestor species in different glacial refugia in southern europe and re - immigrated into central europe after the retreat of glaciation . presently , t . nylanderi is widely distributed throughout deciduous forests in western europe , whereas t . crassispinus inhabits similar habitats in eastern europe ( seifert , 1995 , 1996 ; radchenko , czechowski & czechowska , 1999 ; radchenko , 2000 ) .
skew within multiple queen colonies is known to vary widely among species ( see keller 1993 ; bourke & franks 1995 ; keller 1995 ) , although relatively little variation has been found within species ( e . g . field et al . 1998 ; reeve et al . 2000 ; fournier & keller 2001 ; seppa et al . 2002 ; sumner et al . 2002 ; hannonen & sundstrom 2003 ; nonacs et al . 2004 ; liebert & starks 2006 ) . in ants with multiple queen colonies , the majority of species have low skew as reproduction is partitioned fairly evenly among queens ; a situation known as polygyny . however , there are species in which a single queen monopolizes all reproduction in multiple queen colonies . this rare social organization , termed functional monogyny ( buschinger 1968 ) , has been reported in just a handful of ant species : formicoxenus hirticornis ( buschinger 1979 ) ; formicoxenus nitidulus ( buschinger & winter 1976 ) ; formicoxenus provancheri ( buschinger 1980 ; heinze et al . 1993 ) ; leptothorax gredleri ( see heinze et al . 1992 ; lipski et al . 1992 ) ; leptothorax species a ( see heinze & buschinger 1989 ; heinze & smith 1990 ) and leptothorax sphagnicolus ( see buschinger & francoeur 1991 ) .
leptothorax acervorum populations consist of both single queen and multiple queen colonies . we sampled colonies from a potentially functionally monogynous population : orihuela del tremendal , sierra de albarracin , spain , in 2004 ( ot04 ) and 2006 ( ot06 ) . in 2004 , we sampled in june , before eclosion of sexual offspring , and in 2006 , we sampled in october , after eclosion of sexual offspring and mating . we also sampled colonies from a known polygynous population in sherwood forest , uk , in march and october 2007 . to increase the geographical spread of populations sampled for our study of genetic relationships among populations , we collected colonies from an additional five populations : valdelinares , spain ( v ) ; solvorn , norway ( so ) ; umea , sweden ( um ) ; tvarminne , finland ( tv ) and vaasa , finland ( vn ) . we also used workers previously collected from colonies in santon downham , uk ( sd ) ( hammond et al . 2006 ) .