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PSYCHE,

SKETCH OF THE HABITS OF NORTH AMERICAN ANTS.em I.

BY AUGUSTE FOREL, CHIGNY PRJS MORGES, SWITZERLAND.

Translated by A. P. Morse.

FAISONS, N. C., July 28, 899.To the Belgian Entomological Society,

Brussels.Dear Colleagues"

I am approaching the end of a myr-mecological excursion in North America,and find myself here in the hot, lowand marshy, almost sub-tropical regionof North Carolina (between Goldsboroand Wilmington), under the hospitableroof of my good friend, Dr. Faisons, towhose family the village owes its name.

I think that a report of the most inter-

esting of the results I have secured willbe welcome to you at your next meet-

ing.I have visited at Toronto, Canada;

Worcester, Mass. (at the home of myfriend and fellow-countryman, Prof. Ad.Meyer), Morganton (with my genialcolleague, Dr. Murphy, director of theInsane Asylum), Black Mountain, andFaisons,--the three latter localities inNorth .Carolina.And first, a remark of general charac-

ter relative to what has surprised me in

* Extract from the "Rivista di Scienze Bio]ogiche," vol.ii, 3, Como, 9oo.

The first part of this article, far the appendix, is

taken from the Annales de la Socit entomologique de

Belgique," vol. 43, I899.

the highest degree. In North America,with some rare exceptions, the ants donot construct mounds, either of masonryor of other materials.

In Europe, as you know, ant-hillsabound in every meadow, in the woods,in clearings, among the mountains. Oncoming to a country where the fauna isso similar to that of our own, where so

many species only differ from ours incharacters often but little distinctive,where the tillage, the fields, the woods,closely resemble those of Europe, I wasentirely taken aback when I observedthat the varieties of our most common

species" Zasis niger, alienus, jlaws,tbrmica fusca, sang’uilea, etc., do notbuild any masonry mound, but live inhidden, subterranean nests, openingonly under stones or on the ground-levelby a little crater. But the fact is thesame from Canada to North Carolina.I was forced to submit to the evidence.However, the Americans know what anant-hill" is. When conversing with

them, they refer to it as a great raritywhich can be found in such and such a

forest twenty or thirty miles away. Andon going there you find a colony ofFormica exsectoides, the only species ineastern North America which regularly

t’S [2kugust x9oI

makes large, elevated conical mounds ofearth in the forests. I visited two ofthese colonies in the vicinity of Worces-ter and of Black Mountain. The nestsopen by holes situated at the base andabout the periphery. The workers donot make excavated roads like our tufaof Europe.

Besides these, fformica fisca, r. sub-sericea and pal/idefulva rarely makesmall mounds. As for subsericea, socommon everywhere, I have seen itsmounds only at Niagara, at the side ofthe fall.

After mature reflection I have cometo the conclusion that this singular factdoes not seriously weaken my theory ofthe domes, but rather confirms it. Inmy Fourmis de la Suisse," I haveshown that the elevated dome is used byour ants to collect and concentrate ontheir larvae the radiant solar heat whichthey so much need, and I cited a num-

ber of facts in support of this view. Butthe climate of North America is entirelydifferent from ours. Extremely cold inwinter, it is burning in summer; thereare extremes of which we in Europehave no idea. The ants consequentlyhave quite enough heat and sunlightfor their larvae. The dome is superflu-ous. What they do need is protectionfrom extreme temperatures. For thispurpose it is necessary either to minedeeply or to locate themselves in theshade and in the decaying trunks offorest trees. And that is what they do.At least it is in this way that I explainmost readily this fact, so surprising byits generality.

Another fact to which Blochmann firstcalled attention in Europe in connectionwith Camonotus ligzierdus is the follow-ing. The nests of ants abound above allon hill-slopes facing the east. I have con.firmed this statement since tlaen many a

time, and here in America again. Inthis case also the explanation seemssimple. The morning sun awakens theants and urges them to work. Afternoon it is warm enough, they no longerneed the sunshine. Hence the advan-tage of an easterly exposure which pro-vides for a large amount of daily activity.Toward the west, on the contrary, theywould lose the first hours of the morning,would be unable to work on account ofthe heat after noon in summer, andcould do next to nothing in the eveningto make up for it, once the night wascome. Moreover, the night equalizesvery quickly the eastern and westernexposures, so that the latter do not evenprolong the afternoon’s activity amongthose species which work at night.Ants, then, have every advantage insecuring sunshine in the morning andshade in the afternoon- in America asin Europe.

Let us pass on to some particularcases.The species of fformica of Europe have

American representatives. To ft. tufa,ratensis, truzcicola and exsecla of Europecorrespond integra, obscurifer, obscuriven-tris and exsectoides of America. Wehave seen that exsectoides is the only antof eastern America which makes largedomes. It lives in colonies of five totwenty nests. McCook has seen 5oo

August xgo] .PS 233

to 6oo nests of it. The nests which Ihave seen were all quite conical andbuilt almost exclusively of earth, withscarcely any commingling of leaves andfibrous debris. Some have a little morewoody material. rntegra, still larger,more dimorphic, of a handsome red withthe abdomen ashy black, lives at. thefoot of trees or decayed trunks, fills theinterstices of bark, etc., with woody de-bris and pine needles which stop upeverything, without forming a dome ris-ing above ground. The entire nest isexcavated in the earth or in wood. Thisspecies rises upon its hind legs, curvesthe abdomen, like pratensis (this is notdone by exsectaides) and ejects, as faras I have been able to observe, somevenom while in this position. Dr.Faisons has shown me in a pine woodhere at Faisons a considerable colonyof about thirty nests of this species.These nests were connected with eachother by tortuous roads quite similar tothose of our fi’. pratensis of Europe, butnarrower, deeper, and above all almostentirely covered, that is to say, carefullycovered over with woody materials sim-ilar to those of the nest. Only at cer-tain places were they uncovered for a

length of a few centimeters. The factis very curious and quite new; I thinkthat they try thus to protect themselvesfrom birds and other enemies. Theseroads lead to the trees and nests. Thelatter somewhat resemble those of trund-cola of Europe. Obscuripes occurs onlyin the Far West; I have not yet foundobscuriventris.

As Emery has shown, our slave-mak-ing fibrmica, ft. sanguinea, is representedin America by several varieties. Allthose that I have observed at Niagara,Worcester, Morganton, Tyson’s andlikewise here, attack 2ormica subsericea,often much larger than themselves, andcarry off the pupae. All the formicarieswhich I have observed have a largenumber of slaves, more than in Europe;the slaves in the nest are often morenumerous than the sanguinea. I haveseen several expeditions and two remov-als of sanguinea. The expeditions takeplace in the morning and the pupae arecarried back in the afternoon. All thistakes place as in Europe. I have seensome varieties having the epistoma butlittle emarginate make as many slavesas others having it deeply emarginate.At Mr. Tyson’s (near Black Mountain,at the foot of Mt. Mitchell) when a largeformicary of small sanguinea changed itsnest, the sanguinea almost entirely alonetransferred the subsericea.The latter, although more numerous,

were nearly all in the nest, and allowedthemselves to be transported quietly.In the other removal which I witnessed,the case was the same. This is verystriking, in America, on account of thelarge number of slaves, which are asnumerous or even more numerous thantheir despoilers. In the High Park atToronto I discovered, on the other hand,a large colony of fi’. sanguinea com-

posed of numerous nests (more than a

dozen), built against trunks of deadtrees or by the roadside, and having not

234 /’5" [August, 9o

a single slave. These ants, of a deepred color, slightly emarginate, form theirnests of rather woody materials, a littlelike truncicola. Their aspect was other-wise exactly like that of other sanguineaof Europe and America. They attackedand pillaged a bagful of su3sericea and

pal/idefu/va, which I placed near theirnest, exactly as do other sazguinea,wild with desire like them, to carry offthe pupae. The fact that these insectslived in a populous colony of many nestsand had no slaves remains very curious,to say the least.

2armica su3sericea, which correspondsto our fusca and is only a race of it,lives in the earth and in decayed logs.Only about Niagara have I seen any ofits earthy domes, similar to those of its

European congener.’ormica allidefulva and its innumer-

able varieties excavate their nests in

meadows and under stones.

Camtono/usennsylvanicus and ic/usare very common in trees, the second inthe north, the first everywhere, t’enn-sylvanicus runs rapidly on the roads and

along the trunks, like our ubescens in

the Valais. tic/us is timid and lives in

small colonies in the trunks. 2Wargina.tusand its varieties live as with us in the

bark of living trees, and castaneus is

found in the ground, in the southern

States.Zasius alienus and niger live as with

us but with neither domes nor chambersfor their aphides. They mine solely andare more retiring, only making here andthere little craters of sand. One finds

them especially under stones. Lasiusrayons makes no dome at all. It isfound under stones. In trunks in thewoods is found a large Zasius of a darkand dirty yellow, related to afflnis andmaking its nest in the worm-eaten woodof the trunks. The ,4canthomyots maketheir nests deeply excavated in thefields. One discovers them only at

swarming-time. In this way I securedat Morganton a species of it whichis probably new.

Prenaleis imaris marches in regularfiles in going to its aphides. Its nest,excavated in the earth, is well hiddenand so deep that I have been unable toreach the bottom of it.

trenoteis arvula makes little nestseverywhere, in wood, in dry leaves or inthe earth, and runs about on the turfand in the forests.

27rachymyrmex heeri lives understones, sometimes in the woods; it iswidely distributed.Dorymyrmex )Oyramicus is represented

in the southern part of North Americaby two distinct races, flavus and niger.Both give off a very pronounced odorof Tapinoma (anal glands) and nest

exactly like the yramicus of tropicalAmerica, hunting in the same fashion.Here at Faisons I found a very curiousmixed formicary of these two races.There were two or three nests of themseveral meters apart. The yellow work-ers and the black workers entered .andpassed out peaceably side by side,working together, and presenting everysign of friendship. The two forms were

August, xgox] 235

perfectly distinct--no transition form.I destroyed one of their nests to thebottom and was so fortunate as to findthere males and females of niger andthe male offlavus, the latter larger andpaler. There is scarcely any doubt pos-sible as to the following" This must beone of those rare cases of abnormal,mixed, natural formicaries which I de-scribed in my Fourmis de la Suisse."But this case is certainly not of pre-datory origin, nor due to the carryingoff of pupae as is the case with Formica.It was without doubt due to the for-tuitous association of two fertile females,one of each of the two species, a state ofaffairs which I have already admittedpossible for certain formicaries oftruncicolo-pratenis and which is prob-able also in the association of TajOinoma-2othriomyrmex which I have described(1. c.).The American species of Tapinoma

live exactly like those of Europe andpossess the same odor.

At Morganton I found a little rri-

domyrmex related to humilis, which runswith astonishing rapidity, following infile, hides its nest in the turf (likeCooki) or under a stone, and climbstrees to seek its food. It has a verystrong odor of Tapinoma.The American Ponera coarctata is very

common in decayed trunks and understones. I have made an observationupon it which is very difficult to makein Europe; but here it is quite constant.When one uncovers a nest of t’onera ina rotten tree one sees their yellow co-

coons gathered in a corner, quiteabandoned by the workers, which donot try to save them or collect them.On the contrary they take the greatestcare of the larvae, which they carry offand hide. I suspect that among theseants, less social than others, the pupa,eescape unaided from their cocoons, with-out the assistance of the workers.

I found two Mmblyoona in a rottentrunk and a t’roceratium under the bark.Two days ago, in cutting with a chisel

into a rotten trunk in a pine wood, whatwas my surprise to find here at Faisonssome citon. Two blows more showedme that I had had the good luck to fallupon a nest with its thousands of larvaeand pupae.To my great surprise all the pupae

were naked, without cocoons, contraryto those which have been described andsent to me by W. Mtiller with 2ci/on

burchelli. This little Eciton, of a reddishyellow, is related to californicum andwithout doubt described by Emery. Iat once set to work to demolish the nestin order to discover the female, which isyet unknown (with the exception ofPseudodichthadia incerla Andr6, of whichthe worker is unknown).The trunk was literally impregnated

with Eciton for a foot above and a footbelow the soil. Not a square centimeterof rotten wood was exempt. I demolish-ed everything, down to the ground underthe roots, without finding the female.Finally, in looking over the debris, Ifound it, a long, broad, blind and wing-less creature with immensely distended

236 PSYCI-It. August,

abdomen, moving slowly in the midstof the workers. Its thorax is narrowand somewhat rectangular. The pedicelhas only one joint, very similar tothat of Labidus! The characters are

thus intermediate between the male andthe workers. A leap for joy at this dis-

covery.

About fourteen millimeters long at a guess.Mandibles sublinear, with parallel edges,without teeth, pointed at the end, slightlycurved. Maxillary palpi two-jointed. La-brum emarginate. Scape short, stronglythickened in the second half. Segments ofthe funiculus longer than wide. Head

rotundo-quadrate, with a wide longitudinalfurrow from epistoma to occiput. Thoraxnarrow and elongate, especially the prono-rum and mesonotum. Pro-mesonotal sutureobsolete. Mesonotum oval, subdepressed.No scutellum or intermediate segment.Meso-metanotal suture distinct, concave in

front. Metanotum wider than long, depress-ed, with a wide median impression on the

basal face and two strongly rounded protub-erances on each side. Basal face longerthan the declivent face. Pedicel compressedfrom each side, wider than long, wider beforethan behind, with a superior face and twolateral borders. Its posterior edge is widelyand deeply emarginate, forming thus on

each side a broad obtuse tooth directed back-ward (form of LaSidus). A broad, obtusetooth beneath, in front.The abdomen alone, both distended and

elongate (the entire female is strongly elon-gate) is about nine mm. long. The pygidiumand hypopygium form two wide, elongatedisks, the first convex, the second rather flatand passing the first.

Eyes absent. Legs rather long, permittinglocomotion. Tibiae and femora scarcelysub-depressed. The whole insect shining,finely punctate, except the thorax and the

pedicel which are plentifully and morecoarsely punctuated. Pile erect, fine, yellow-ish, abundant, pointed, generally distributed.,Reddish. Legs and antennae a dirty yellow.

I placed a part of the nest in a bag inorder to observe these interesting ants,and I have not yet finished studyingthem. Unfortunately there were in the,

nest only pupae and larvae of workers.I found a myrmecophile in it. Thefollowing observations seem to me im-portant to record" The Ecitons carrytheir larvae and pupae, which are veryelongate, by placing themselves astrideover them with their six legs, likeIolyergus but in a more accentuatedfashion. Even the little workers carrythe large pupae in this way, touchingthe ground only with the ends of thetarsi. But by so doing they travel veryfast and have the antennae free. Inthe second place, their instinctive facultyof concerted action and of forming inline quite excels everything I have seenamong other ants. Throw a handfulof Ecitons with their larvae down uponstrange ground. Under similar circum-stances, where other ants scatter them-selves about in confusion and requirean hour or more (sometimes less) toarrive at any kind of order, to gathertheir pupae and especially to examinetheir surroundings, the Ecitons co-operate without losing a single instant.In five minutes they have formed distinctfiles of workers which do not wanderfrom each other, carrying in part thelarvae and pupae and traveling in asomewhat direct line, touching the

August, PSYCttE. 237

ground with their antennae, exploringall holes and cracks until they find a

cavity suited to their needs. Then theremoval is executed with an order andcelerity which is astonishing. As if byword of command the workers followand understand each other, and in verylittle time everything is safe. There isno question of mutual transportation" itis more precisely the system of Tapi-noma. The fact is remarkable in thecase of a blind ant which has only itsantennae with which to direct itself.The American Aphaenogaster which I

observed are all great hunters and sub-sist upon the insects which they catch.They are very fond of termites, andwhen one uncovers and scatters about a

nest of termites in a wood, they hastento feast on these succulent morsels. A.fulva is most common. It variesenormously and nests in rotten logs orunder stones, especially in the forests,sometimes in rather large formicaries.A. tennesseensis makes immense formica-ties in rotten trunks. I saw one of themnear Niagara. In trunks of trees atMorganton and here, at their foot orunder the bark, I found rather largeformicaries of a beautiful species (lam-ellidens or mariae). Finally A. treatae,which abounds in the forests at Morgan_ton, Black Mountain, near Mr. Tyson’s,and here, in all parts of North Carolina,excavates little nests in the ground (never

caries are not numerous. I found butone rather large one at Mr. Tyson’sand the workers boldly attacked mewhen I disturbed it.The American species of &ryrmica

have the same habits as the correspond-ing European forms and present nOth-ing of interest. It is the same withLepta/borax. One species of the lastmakes its nest in curled up dead leaveson the ground. I found it by followinga worker which bore a pupa. aDichotlzo-tax nests here at Faisons in small, dry,fallen branches among the dry leaves ofthe forest and feigns death. A fyrmi-ca found at Mr. Tyson’s and related toM, rugulosa also feigns death on everyoccasion.

I have just found here two formicariesof 2ogonomyrmex badius Lair. (--" trans-versus Sm.--crudelis Sin.). This speciesmakes, in barren fields, a fiat, rounded,dome-crater, covered with little stones.It stings in a terrible fashion. Havingattacked it imprudently, I received twostings on the hand and suffer from themstill, several hours after. Its stings aremore severe and painful than those of ourVespa germanica of Europe. As has beenremarked by Mrs. Mary Treat this spe-cies does not cultivate any special plantand makes no clearing around its nest bycutting down the plants. But Mrs. Treatwas wrong in concluding from this factthat the same holds true for ’. male-

in logs), sometimes under stones. These facieus of Texas. _P. badius gathers sev-nests open by a large, widely open hole, eral kinds of seeds in demolishing itsrarely two. The workers go out singly nest I discovered its granaries whichand are fearless hunters. The formi- are very flat, but well arranged.

238 _PS [August, I9o!

On lifting up a stone at Black Moun-tain I saw a brown ant withdraw itselfinto a gallery. The magnifier enabledme at once to recognize Atta (Y’racy-myrmex) tardigracl Buckley Themushroom garden of this single north-ern species of the group being still en-

tirely unknown, I set myself in quest ofit. The workers issued first in ratherlarge numbers to defend themselves, es-

pecially when I placed before themsome Cremstogaser. Soon I saw come

up from the bottom of the nest some

workers carrying little gray balls withwhich they obstructed the opening.judged that these were from the mush-room garden and proved it by takingone of them in my forceps. Did theyseek in this manner to repel the Cre-mastogaster by the odor of the mush-room Did they wish to prepare forflight I do not know. Some of themstrangled several of the Cremaslogasterwith their mandibles. Finally I decidedto open the nest to the bottom. It wasnot deep. It consisted of a large cham-ber the size of an egg and was filledwith a mushroom garden which enclosedthe pupae, several females, etc.

This nest recalled one made by some

captive dtla (dcromyrmex) octosinosa inthe earth under a saucer. It containedabout two hundred workers. I placed a

part of the mushroom garden in alcoholand tried in vain to make the myceliumof the rest grow in a damp vial. I shallsend it to Prof. Moeller. McCook hasclaimed that A. tardigrada cuts off theneedles of pines and firs. There were

none of these trees in the vicinity of thenest. As Tracymyrmex makes a mush-room garden simpler than the other Attaand as their fungus is not Rhozites, Isuspect that tardigrada employs othermaterial (detritus, larval excrements,etc.) like the other species of the sub-genus which I observed in Colombia.The Cremasloga’ster /.ineoZata, as/meatii

etc., of North America live, especiall3rthe latter, by preference in rotten trunksor in branches fallen to the ground inthe forests. In these they make largeformicaries. They are found understones also. especially lineo/ata. Theydo not use dry, hard trees like scu,ellaris

of Europe, so that their nests are easyto demolish. However, their habits areuninteresting, like those of nearly allCremastogasters.The species of ])aeidole are numerous

and live under bark or in the earth inexcavated nests with small crater-likeopenings. At Black Mountain a speciesmakes large, almost dome-like nestswhich are very populous. Here at Fai-sons I have found several species ofthem under bark. At Morganton Iwitnessed the marriage-flights of themales attd females which appeared inswarms in the early evening in front ofthe Asylum.Monomorium ebeninum is very common

and lives here, as in the Antilles, in drybranches, very often in those fallen tothe ground in the forests. I witnesseda removal.

Various species of So[enasis live indouble nests as in France and elsewhere

August, 9o] tSYCI-IE. 239

with various large ants, especially withFormica exsectoides, subsericea, etc., butvery often with termites also, particular-ly in rotten trunks where they insertthemselves between the passages of theirvictims.

I cannot finish this short notice of thehabits of the North American ants thatI have observed thus far, without thank-

ing most sincerely my good friends andcolleagues Dr. Ad. Meyer of Worcester,Dr. Murphy of Morganton, and Dr.Faisons of Faisons, to whose aid, hos-pitality and inexhaustible kindness Iowe all that I have discovered. NowI go to visit the able American myrme-cologist Mr. Pergande at Washingtonand thence return to Europe.

LIFE HISTORIES OF NORTH AMERICAN GEOMETRIDAE.--XXIV.

BY HARRISON G. DYAR, WASHINGTON, D. C.

lois inductata Guen. The moth fromwhich these eggs were obtained was in verypoor condition and the larvae died beforepupation, but I believe that the determinationis correct and that there are no more larvalstages. There is no previous description ofthis larva.Egg. Long and nearly cylindrical, less in

one diameter but not with any flattened sur-face one end first a little bulging, then taper-ing to a round blunt point, wedge shapedfrom side view, the other end (micropylar)roundedly truncate. About eighteen longi-tudinal ribs, fluted at the ioinings of the faintregular cross-striae which form square cells.Ribs diminishing by a few before the ends;micropylar end coarsely irregularly reticu-late. Pearly white, looking beaded from thefluted ribs. Length .9, width .4 X .3 nm.The next day turned pink, shading to red atthe truncate end.Stage L Head rounded, free, slightly

bilobed, luteous, faintly mottled with brownwidth .3 mm. Body slender, whitish, a rath-er broad, even, brown-gray dorsal band, sep-arated on joints 2 to 4 into four diffuse lines,but soon merging into a single, broad dorsalband to ioint t3; a broad subventral band,

the pair separate. Tubercles pale, nearlyobsolete; setae short, dusky with small en-larged tips. Feet pale; segments finely,about o-annulate. Anal flap pale. Seg-ments scarcely enlarged centrally, uniform,smooth. After feeding turned greenish bytransparency.Stage II. Head round, scarcely bilobed,

free; whitish, a white stripe on the face ofeach lobe, containing an isolated brown dotopposite middle of clypeus many brown dotsfilling the median suture and apex of lypeus,also on the outer side of the white band;labrum pale; ocelli and tips of antennaebrown-black width .4 ram. Body moderate-ly slender, smooth, normal, segments, numer-ously (about o) annulate, but not distinctly;setae short, black, rather coarse. Dorsumbroadly dark brown, cut near its edge by alinear, slightly flexuous, pale yellowish sub-dorsal line, most distinctly at the ends and inincisures sides pale green; a broad subven-tral band, colored like the dorsal one andslightly intensified at tubercle vii on eachsegment. Venter pale green rather narrowly.Cervical shield more reddish than the rest ofthe dorsum. Feet all pale.Stage III. Head rounded, not bilobed,

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