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Yes yes, nice texts... Some informations are knowly for me, did´t you wokr with books of B. Seifert? But also nice inteligent texts, thank you much!
Hello,
No the only informations a bit detailled that I did get about the Myrmicas came from old numbers of
"Insectes Sociaux " and from the book of A. Raigné , newer books give some small informations about the
Myrmicas (some also mistakes) probably because they are difficult to observe in the grass and bushes where they live and because keeping in artificial nests give the false impression that we know nearly everything about them. I did not know the book of B. Seifert but if it is translate in English I will try to get it.
Hi,
After nearly two months (I realy did not find the time) I will continue to write what i observed about Myrmica rubra, M. ruginodis ,M. sabuleti ,M. scabrinodis specialy when competing with other ants .
Myrmica rubra need hunting ground ritch in soft body preys small enough for one ant to kill but can catch collectively bigger soft body preys near the entrance of theyr nest or retreave these preys dead or dying.
the collection of sugars from aphids ,flowers ... is just a usefull supplement. The Lasius exployte the aphids as theyr main reliable food source and are the dominent ant in divers microclimate if there is a minimum
of direct sun and so is also the pionneer specie in disturbed habitats. So the succes of Myrmica rubra depend of it's capasity to invade and keep the hunting territory occupy by L. niger .The Formicas replacent the Lassius later, after many years without major disturbance. So I am going to describe how Myrmica rubra fight of succesfully Lasius niger and invade theyr territory to become the dominent ant in many area.
In central europe after the destruction of all or most ant nest in a grass area the largest number of founding queens who land and succede to start a colony are those of Lasius niger,some Lasius flavius a few of Tetramoriums and Myrmicas scrabrinodis or M.sabuleti: L.flavius been entirely subteranean avoid competing much with L.niger ,the Tetramoriums are resistants and dominent on theyr small territory,M.sc. and M.sa. are non territorial and subdominent as long as they are outnumbered by L.n and theyr narrow gallerys make easy the deffence of theyr nest .
Most of the Myrmicas rubra queens who escavate a nest or the new born colonys are destroyed very agressively by L.n who vastly outnumber them :The Lasius are economicaly more efficiant and the queen much more prolific so theyr colony grow mutch faster. So Myrmicas rubra queen succed to establish a colony only rarely when they find a space unoccupy for exemple in the shade. From there the colony grow until it have several hundred workers ,at that stage it can resist and even go on the offessive.
In a individual encounters, when a Myrmica rubra or M.ruginodis fight with a Lasius niger the combat is very short ,violent and deadly ,the ants rolling on the ground ,the Myrmica grip the Lasius to sting it wile biting the thorax or the neck ,the Lasius niger try to keep loose (without success) wile spraying formic acid/poison, after a few segonds it is over. Out of five individual encounters 4 finish with the dead of the Lasius, 1 with the dead of both ants ( score 5 to 1).
So if the L .n . do not vastly outnumber M.r ,it have no chance of winning but it is mostly by fighting collectively that M.r. .have the edge. I will describe the combats I observed later.
Myrmica rubra show different degrees of agressivity depending on what sort of ant from other colony it meet : the Leptothorax are tolerate and these ants avoid eatch other nest entrance.M.rubra of sister colonys
avoid each other territory even when the nests are relatively close, when a encouter occured the ants wressel until the stronger one carry the other away from her territory, the other immobilise itself and a few seconds after been released move again and go away.When the colonys are less closely related the fight is more violent and may sometime result in the dead of one ant but they hesitate to use theyr stinger.When the colonys are apparently not related or belong to a different speecy the combat is to the dead with use of the stinger exept if the weaker one succeed to escape but even so I never see these ants lauching a group attack against other Myrmicas. These single combats are often 20 ,30 or 40 minuts long and so are often seen.
By contrast combats with Lasius are very short and deadly involving group action. Serviformicas use theyr
speed and greater agility to avoid the M.r and to still preys from them .They avoid groups of Myrmicas.
When Lasius niger recrute for deffence or for attack these ants follow the odor track in disorder without organisation or interaction in the same way they expoit food source and arrive to the fighting individualy.
By contrast M.r. scouts avoid combat localise the ennemy concentration recrute nestmates until they concentrate in a group strong enough near the ennemy concentration (nest ,food source and so on)and at once lauche the attack as a group with a surprising agressivity at a signal probably olfactif. These attacks are made by a comando of about 50 ants maximum and if it is not succesful they usuly renounce but more reenforcements occure when it is for the deffence of the immediate surounding of the nest.It is not big battles as in Tetramorium but more guerilla and commando warfare.
I observed colonys of M.rubra and M.ruginodis surviving a few meters from nest of Formicas of the rufa group. These Myrmicas lived entirely of small preys like springtails ,all bigger preys and dead insects been stollen from them by the Formicas. When a Formica approched the entrance of theyr nest they go out attaking it. Once a group of 4 or 5 Formicas approched the entrance of a M.r. nest and 50 to 100 Myrmicas run out furiously attacking the wood ants, the Formicas run away with Myrmicas hanging to their legs and antenas I can not say if the Myrmicas did find the way back to theyr nest or if the Formicas survived the
stinging by the red ants.
Contrasting with territorial, agressive M. rubra and M.ruginodis ,M.sabulety and M. scabrinodis baricade themselves in theyr nest when other ants aproche to much for confort or attack them ,and become agressive only when they find themselves in force ,in that case they attack the Lasius niger all at once kill those who do'nt escape to cease the food but contrary to M.r. do not pursue further the attack.When M.scrabrinodis or M.sabulety fight Lasius niger or L.alienus out of five fights two finish by one ant running away, two times the M.s. kill the lasius and one time both ants die:score 3 to 1 .Only very rarely the Lasius winn.
Next time I will explaine the working of the territorial expantion of M.rubra at the expance of Lasius niger but
before we must realise that Myrmica ruginodis in forest is the main pioneer specie and generaly just eliminate colony in theyr initial stage: A queen with few workers.
When a queen of Myrmica rubra succede to establish a colony that grow to a size big enough to resist Lasius niger (or Serviformicas) and that the conditions are favorable the colony grow faster by adopting other queens
and exploiting the best hunting grounds and also groups of plant bugs (aphids)taken and kept from L.n. .
To find the best local conditions and proximity from hunting ground the colony can emigrate easily often
one meter in prairy or lawn but sometime 4 or 5 meters. Ones ,in june , during a hot and very dry spring I observed a big colony of M.rubra moving along a footpat from the sunny slope of a road side to the shade about then meters away. Some colonys who are established in very favorable conditions for exemple under a fallen tree branche in wet but sunny place may stay at the same place years after years ( exept in the cold season when they live in a separate winter nest) but that is the exeption : They move usualy two or three times in the season and I observed colonys that move three times in three weeks.That contrast with L.niger who stay at the same place years after years at most moving the center of gravity of theyr nest once in then years.
When the Myrmica rubra colony reach from three to more than five thouzand workers the colony lost its cohesion , often forming two different nests .In automn the colony emigrate in two different winter nests, get different smells and so became hostile to each other ,forming two differents colonys.In verry favorable conditions colonys may probably split every year or so, looking for new territory to exploit.This is limited by eventual parasites and sometime destruction of nest by trampeling of grazing annimals.
The behaviour of Myrmica rubra foragers and scouts in encounters with L. niger depend of the size of the Myrmica colony and aparently of the number of workers of L asius niger living theyr odor when walking compared with the number of passages of nestmates. Myrmica r ubra territory is the nest, its surface ,immediate surrouding , one to several hunting grounds and sometime groups of aphids. When a forager encounter a L.n. in one of these areas it attack furiously and kill it if it catch it. When a forager , spetialy a old one acting as scout detect the presence of several L.n. it become very alert ,try to get more detection and then go back fast and exited to the nest,to start the alert then a number of foragers scouts go out of the nest following more or less the original scout at the begining but slowly,carefuly spreading asides ,attacking the Lasius they find as long as they feel more numerous . Often they continue in theyr way looking for L.n. concentration .When they feel outnumbered then they avoid combat and acting as scouts go back to theyr nest and bring back new fighters until they form a concentration near the ennemy then at once they attack in mass . These actions far from theyr nest do'nt seems to involve more than about 50 workers of the older age class so it is so highly improbable that they ever attack directly a mature nest of Lasius niger but instead deprive L.n of theyr hunting grounds and aphides herds. As a result the Lasius niger territory and colony size shrink and survive that way surounded by a majority of M yrmica rubra colonys. That is the situation in area of high density of Myrmica rubra . L asius niger are relagate to be little active outside and only at night and become mostly subteranean. If Formicas are also present (they are predators of Lasius) Lasius niger can be eliminate totaly( localy). By split ,emigration of theyr colonys in territory they did conquest the Myrmicas can invade the area occupy by L.niger without attacking directly theyr main nests.
Hi Amrik
Some good observations of how Lasius Niger and Myrmica Rubra interact. In my back garden I also have both species. The edges of their territories do cross over and have witnessed different outcomes when it comes to competing for food. Some times Myrmica Rubra dominate and then other time Lasius Niger dominate in the same area. We did have a colony of Myrmica Rubra on the edge of our patio located under a flag stone. These for some reason disappeared and were replaced by Lasius Niger (not sure if they just filled the void or were displaced)
In terms of combat Myrmica Rubra tend to be very aggressive and charge in all guns blazing. While Lasius Niger tend to be equally aggressive but work more as unit collectively killing the Rubra by pulling them into their ranks. The Myrmica Rubra will attack and endeavour to this alone irrespective whether it has strayed into the ranks of the enemy. The other advantage that Lasisus Niger possess is greater numbers, often more populous and will succeed by numbers. When this happens the Myrmica Rubra retreat back and allow the Niger to dominate the food source.
The other strong holds of the Myrmica Rubra in my garden remain in tact.