Slave‐Raids of the Ant Polyergus Lucidus Mayr

Since slave-making raids of t,he genus Polyergus are conspicuous and spectacular, they have been studied by a number of myrmecolo- gists.Among these are Wheeler 9 IO), Forel (I928), Creighton (95o), and Dobrzanska and Dobrzanski (96o).This paper con- cerns the eastern "shining slave-maker," Polyeryus lucidus Mayr, on the.Edwin S. (]eorge Reserve in southeastern Michigan (Livingston County).Twenty-five colonies of this species have been found, scat- tered quite widely over the fields, on the a square miles of the Reserve.Most .ofthe.fields tend to be dry, wit'h Canada bluegrass (Poa compressa L.) the dominant grass and with forbes .suchas wild bergamot (Monarda fistulosa L.) bush-clo.ver(Lespede'za virginica (L.) Britt.), and goldenrod (Soli'dago spp.) common and char- acteristic.In addition to this main habita.t,Polyer'yus colonies may sometimes be found at woods' edge, in low wet fields, and in openings in oak-hickory woods where blueberries (Faccinium angustifolium Aft.), bracken (Pteridium aquilinium latiusculum (Desv.)Un- derw.), sedge (Carex pennsylvanica Lam.), and mosses are char- acteristic.No colony has been found completely within the woods, although the slave ant Formica pallidefulva nitidiventris Emery sometimes occurs there.The slave-raid study was undertaken in the hope of determining the time of day of raids, and the environmental factor.swhich influ- ence the time, the days on which no raids occur and the factors which determine this absence, the number of slave colonies, used in the sup- port of one Polyergus colony, the distances to these colonies and the amount of time it took to reach them, the.number of raids in a sea- son, the number of brood taken, the size and characteristics of a raiding force, and the method by which the band of ants could travel over a seemingly unknown pat'h to.arrive exactly at a nest to be raided.Preliminary studies were made on the Lawn Colony, which lived in the cut grass outside the East Gate Laboratory and had been known *The facilities of the University of Michigan's Edwin S. George Reserve were made available by the Reserve's administrators, Dr. F. C.