1957] 
Kannowski — Leptothorax provancheri 
3 
have a much more extensive range than that which is 
presently known. The rarity and limited distribution of 
this species seem to be due to three factors: 1) very few 
areas within its hypothetical range have been studied 
intensively; 2) provancheri workers may easily be over- 
looked because of their small size and relatively few num- 
bers (in comparison with the numbers of the host species) ; 
3) because of environmental factors, its range is more 
restricted than that of its hosts. 
The apparent absence of provancheri in bogs in south- 
eastern Michigan indicates that the factors governing its 
distribution are different from those governing the distri- 
bution of the two host species. The bogs that have been 
studied in Livingston, Washtenaw, and Cheboygan coun- 
ties are composed of similar plant communities, and the 
edaphic conditions are similar. Climatic conditions seem 
similar except for the extremes of temperature found in 
the two regions. Summer temperatures in southeastern 
Michigan are higher than those of Cheboygan County, and 
these high temperatures occur for longer periods of time. 
The temperatures in southeastern Michigan may be too 
high for the proper development of provancheri colonies, 
although this factor may not be critical in the case of 
the two species of Myrmica. The presently known range 
of provancheri strongly suggests an adaptation to regions 
of cool temperatures. 
Myrmica fracticornis has not previously been recorded 
as the host of any inquilinous ant, probably as the result 
of insufficient study of ants in the moist environments of 
northeastern North America. Additional records should 
turn up in the future. It also seems probable that other 
species of Myrmica may be found as hosts of provancheri. 
Seven provancheri workers were kept for about two 
months in an artificial nest with a small fragment of the 
fracticornis colony, including one queen, four alate females, 
three males, about 50 workers, and a small quantity of 
larvae and pupae. Random observations of the mixed nest 
during this time showed that the provancheri workers were 
accepted by the fracticornis colony ; no evidence of hostility 
between the two groups was ever observed. The two 
