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I can now compare hunting behavior of Myrmica rubra , Tetramorium caespitum and Pheidole pallidula .
-Myrmica rubra hunt mostly by inspecting rapidly possible prey's hide out and resting places, they catch small preys by reacting fast and kill preys like a mosquito or a small caterpillar by biting and if the prey struggle strongly or fight back by stinging. They attack also bigger,fast moving preys but usually without success and sometime ,doing so are drag to far away from their nest. They attack large preys in group only very near a forager alert room. They transport large preys collectively back to the nest but are not very good doing so .
-Tetramorium caespitum do not try to catch fast moving preys like adult insects , they are hunting mostly insect larvae of every sizes using group and mass recruitment and feed much on insect pupae. They move slowly employing to the maximum their sense of smell and maybe also their sight .They kill preys by strong biting and stinging . Tetramorium caespitum usually butcher their preys on the spot , empty the carcass and make very little effort to drag preys to cover.
-Pheydole palidula hunt in group very efficiently using fast group or mass recruitment but once the prey is immobilized they are limited by the capacity of the soldiers to kill it . They are very efficient and fast retrieving large preys collectively back to their nest.
I did give a 5 cm earthworm to the T.c. this morning and I was surprised of how fast they killed and cut it to pieces.
The brood of the smaller colony is growing again now . They seems to have recovered well from the previous problems .
You can see that the small colony (rear-left)have transfered in a bassin with the vertical plaster nest connected to the arena ,the old nest have been removed.
The large colony have been connected to a " ant apartement " that I use as a simple bassin with a big plaster nest . Other nests contain Solenopsis fugax covered with a cardboard .
The grow of the large colony's continue at the same pace , it occupied now the two nests ;the Tetramorium make so many gallery's in the wet part of the first plaster nest that I can't see all the colony but I think it reach now 2000 or 3000 workers . They eat now each and every day 4 large Tenebrion pupae or wax worms or small earthworms and 8 decorticate sun flower seeds . Since yesterday I give them also dandelion seeds, they like it and to my surprise not only they harvest the seeds quickly but they also seems to eat the small parachutes .
The small colony have now not only recovered from the serious problems in the first nest ,now abandoned, but now the brood
is plentiful and the colony grow fast again eating one large Tenebrion or two small wax-worms per day and the equivalent of one sun fl. seed.
It seems funny but Myrmicas rubra who live in wet ground were there are plenty of earthworms never like to eat them except when they are very small or when these ants are starving . But Tetramorium who live in drier ground poorer in earthworms like much to eat them.
I now give dandelion seeds without their "parachutes " because they seems not to eat them eventually and it is messy , especially if it stick to the oily anti-escape . They are very quick to collect any dandelion seeds I give.
I think the small colony is now more than three or four hundred workers strong . It is now very active with much brood .
If ,in volume, the seeds are less than animal food ,in dry weight it represent probably about 60percent of the food intake of the big colony ( the small colony less ). This correspond with what have been observed in the wild : Some sorts of SMALL seeds represent a major part of Tetramorium caespitum food intake (they can eat sun flower seeds well because I removed the husk).
Following what I did read , observed myself in wild colony and artificial nest it seems that Tetramorium caespitum biggest food intake come from small seeds (dandelion , clover , heat , grass... ) .The animal food is constitute of slow moving preys: diverse insects larvae ( caterpillars, maggots , beetle larvae ...) of every sizes and earthworms and carrion of not only insects but a dead lizard , mouse or bird when the occasion occurred. They keep aphids on plant roots only but it seems to be a less important part of their diet. They use foraging gallery's and tracks (mostly covered) and forage far on the ground and underground without climbing on the vegetation , they like the heat but do not like to forage in full sun . Tetramorium does not hunt large fast moving prey except if they constitute a danger or a competitor.
The number of workers in the smallest colony is now several hundreds (I can't count any more) and growing fast .The food intake is now equivalent of two tenebrions pupae +sun flower seed + many dandelions seeds.
The population of the biggest colony is now a few thousands (impossible to count) eating the equivalent of 5 or 6 tenebrion pupae , 8 sun flower seeds and a large quantity of dandelion seeds every day.
It is well know that Tetramorium caespitum is an easy sort of ants to keep, tolerant of less than optimal conditions.
I have always found curious that many colony's of T.c in Belgium are languishing in places without enough sun or heat with a smaller, less dynamic population . On the other hand in sunny , warm microclimates they form big , active and dynamic populations .
Ideal temperature for Tetramorium caespitum are those found in southern half of France north of the mediteranean coastal area, north Italia , South Germany , Switzerland continental climate area with warm summers in north America . In these area their dynamism and the population of their colony's can be spectacular and they are the dominant ant specie .South of this area along the mediteranean coastline they occupies shady, wetter places .
So we can conclude that Tetramorium caespitum prefer a warm and moderately dry climate during the active period that permit them to develop to their full potential.
Hello again,
I just have just read an article from a team of the University of Natural Resources and Applied Life Science Vienna (Austria ) concerning the Cryptic diversity of the Tetramorium of the caespitum group in Western Europe and North America dating from 2006 .
Tetramorium workers are variable withing the same specie Sometime more so than between species so this studies employed mostly genetic and physical elements that agreed genetic boundaries between species.
doing so they identify a number of species but retain only those who were
represented by a sufficient number of samples and give a geographic repartition map to each.
They describe 8 Species and give a letter instead of a name to avoid argument about names given before: specie A close with Tetramorium specie F in mediteranean area.
'' F ( T. caespitum) in northern central Europe down to north Italia and Hungaryand east to Kiev.
" B from Greece to south Germany and south Ukraine.
T. hungaricum from Greece to Hungary .
specie C in eastern Europe.
" D in south Europe in Spain and to Hungary and Bulgaria .
" G (T. impurum ) from Belgium to Hungary and in Spain .
" E related to T. impurum In southern Europe from south France near the Spanish border to the Caucasus and from Hungary to Greek islands . It is the specie that have spread to north America .
Tetramorium sp. E is more aggressive than his relative Tetramorium impurum and can better take advantage of hot summers of south Europe and the continental climate with hot summers in north America. It is surprising that T. sp. E is not only more closely related to Tetramorium impurum than to T. caespitum but also that most if not all European Tetramorium in north America are T. sp.E wile it was considered that it have arrived in north America several times.
Tetramorium sp.E must have come probably to north America more than 300 years ago aboard a ship coming from Southern France or Italy.
surprisingly In Canada and some parts of the US it live in area with much colder summers than in South Europe.
The maps that the Austrian team led by B. C. Schlick-Steiner and F. M. Steiner have produced are highly interesting but limited
by the small number of sampled areas so it can give only a general idea of the Tetramorium gr.caespitum species repartition as many areas are not represented . For example all species with sufficient number of samples ( except T.sp. c ) are represented in Austria so we do not know if it is because Austria is an area where species of the South , North and east , mountains and low elevations meet or if it is due to the larger number of samples in Austria . Both explanations are probably true .