ANTSTORE World of Ants

[amrik singh]

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.

[amrik singh]

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.

[amrik singh]

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.

[amrik singh]

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 Lasius niger living theyr odor when walking compared with the number of passages of nestmates. Myrmica rubra 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 Myrmica rubra colonys. That is the situation in area of high density of Myrmica rubra . L asius nigerare 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.

[sianhilton]

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.

[amrik singh]

Hi,
It seems that the M.rubra colony was to close to the L.niger nest for comfort as L. niger will not have
move anyway ( they are the sedentary sort of ants)so the myrmicas moved away, or maybe they move to a wetter place or nearer their hunting ground. Myrmica r." consider" as their territory the area of the nest and immediate surrounding plus one or two frequently shifting hunting grounds often some distance from the nest. Away from the nest area they seems to"consider themselves on their territory where they are the most numerous , when they are much outnumbered they usually back of. When a Myrmica r. worker stray in the middle of a L.n. concentration it have all the chances to be killed however the M.r. scouts are very careful and alert and avoid been catch instead running away to give the alarm .
Some years ago I have seen two confrontations that looked like what you have observed: part of one relatively big M.r. colony occupied a howl in a pavement who was vacated when the weather became warmer and dryer. Later the nest was occupied by a advance post of a L.n. colony. When the confrontations between the Myrmcas r. and L.n. become more frequent the Myrmicas scouts became very careful recruiting nest mates until they became about 50 in number near the Lasius front post and then attack very aggressively as a group killing all the Lassius they could catch.
At an other place I observed a group of plant bugs on a one meter and a half fruit tree attended by Lasius niger then a group of 6 or 7 Myrmicas attacked killing two or three Lassius n. then in the evening the L.n.came back and the myrmicas evacuates without fighting. In the following morning the M.r.came back and the Lasius run away without fighting .This did go on for several days.

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[amrik singh]

I have to add some precisions about what I wrote before to feed Myrmica in formicarium : Adult ants feed on
liquids because their bucal and digestive system is not made to eat solid food and the workers need to feed mostly on energy food. Adult workers wasps and primitive ants fed almost exclusively on sugar rich food .
This is also the case for dolichoderinae and formicinae like Lasius but others feed mostly on hemolimphe (arthropode blood) , on sugar derive from the processing of seeds or on nuts oil and animal grease.
When the Myrmica larvae are still small or few compare with the number of adults the food consumption of the
larvae is not enough to eat the insect meat left after the workers have finish to drink the hemolymphe and the insects leftover are left to rot in the nest. So it is useful to give some sugar or honey to Myrmicas despite the fact that it is not indispensable .

[badman]

are the nesting habits of M. Ruginodis any different to M. Rubra?

[amrik singh]

Well, I think that Myrmica ruginodis nest mostly in forest in more shady places often in rotten wood, Myrmica rubra nest more in open area at least in central Europe but you can find Myrmica rubra in forest and Myrmica ruginodis in prairie so it is not an absolute rule. Colony of Myrmica ruginodis multiply mostly by independent foundation by a lone queen and have not so many queens, often one,and the colony is not so big apparently . Myrmica rubra multiply largely by separation into two daughter colony and have more queens and more workers, they seems to me to be also more mobile.

[amrik singh]

To what I wright before about hibernation of Myrmica rubra I must add this : The brood of Myrmica r. at the end of the active season mature until adults emerge except the small larvae at the first two stages of development who stop to grow until the following spring . Apparently this seems not to be entirely temperature dependent but preprogrammed .
One year in summer during a big drought all Myrmicas r. vanished from sight and one day I found by chance a colony relatively deep underground concentrate in a very small space, like in hibernation, with only the two first stage larvae present, and this during a hot and dry summer.

[amrik singh]

The temperature outside have been between 28° c and 32 °c maximum for a few days so the temperature in the house have reach 27/ 28° c but the Myrmicas rubra seems not to have suffer from the heat and had just
became more active. Now the temperature in the house is down to under 25° and the activity slow down to a normal level.

[amrik singh]

I observed myself what I have written about the competition between Lasius niger , Myrmica rubra and other ants but it seems not to be always true . In marginal places of Myrmica rubra distribution ( Not rich enough in preys , to dry,...) it seems that they formed colony's of no more than 500 workers with 1 or few queens an are so not dominant at all .
On the other hand , in some places Lasius niger attain a very high density of population due to their attending of aphids and can eliminate ants that are normally stronger and much better fighters just because of their overwhelming number and agressivity .

[amrik singh]

Hi,
It is also possible that Lasius neglectus may sometime be misidentify as Lasius niger .
We often see that ants who feed mostly on aphid exudate and don't fight between neighbouring nests can reach very high density of population with nearly unlimited number of workers, so even if these are not very good fighters they dominate by overwhelming number .