long legged, are usually reddish brown, and vary in 
size from 3.2 to 7.0mm. They forage in leaf litter above 
the ground and in low vegetation, feeding on a variety 
of foods. They nest in rotten wood, under stones, and in 
the soil, often making a slightly elevated area on the 
soil where they have deposited particles from the nest 
excavation. Each nest may have up to 3,500 workers 
and several queens. 
These ants are frequently abundant in the garden; 
only rarely does one get into the house. If they locate 
a nest in a lawn, they may be a persistent nuisance for 
some time and will frequently inflict painful bites when 
disturbed. Otherwise, they are not pests. 
31. Myrmecina Curtis 
The two North American species, both native, occur 
in Illinois. The workers are reddish brown and range 
in size from 2.5 to 4.5 mm. They construct small nests 
in rotten wood or leaf litter, primarily in woodlands. 
They are only rarely found in homes. 
32. Stenamma Westwood 
The three Illinois species of this genus are all natives, 
similar in size and general appearance to those of the 
preceding genus. They make their nests chiefly in leaf 
mold and are restricted to woodland situations. 
33. Pheidole Westwood 
This is primarily a southern genus, having over 40 
North American species of which only 2 have been found 
n Illinois. The workers are dark brown and range in 
ize from 2.5 to 4.5mm. The nest is made under stones 
r in soil, commonly with openings between cracks in 
idewalks. Each nest may contain several hundred 
vorkers. The small workers have normal-sized heads, 
he larger workers greatly enlarged heads with massive 
nandibles, and these differences are correlated with their 
ood habits. They naturally feed primarily on small 
lant seeds that are brought into the nest by the smaller 
vorkers and then cracked into fragments by the large- 
eaded workers. Around homes these ants nest commonly 
n the garden and frequently enter the house, where they 
eed on a variety of domestic foods. 
4. Myrmica Latreille 
Of the 11 native American species, 4 occur in Illinois, 
he workers are reddish brown and range in length from 
2 to 6.0 mm. They build nests in the soil, each nest 
sually containing only 50-100 workers and one queen. 
he workers forage in litter and low-level vegetation. 
though they usually occur in woodlands, they may at 
mes be common in lawns. 
9. Tetramorium Mayr 
Only a single native species of this genus occurs in 
linois, T’. caespitum (Linnaeus) , the pavement ant. The 
orkers are almost black, 2.5-3.5 mm long. The nests 
fe made in soil, often under stones, boards, or sidewalks. 
1 the house the workers eat a variety of domestic foods; 
21 
Fig. 27—Pharaoh’s ant, Monomorium pharaonis. 
after losing her wings; B, worker. 
A, queen 
Natural size of queen, 4 
(From USDA) 
mm; of worker, 2 mm. 
in the garden they may steal seeds and girdle the stems 
of garden crops. 
36. Leptothorax Mayr 
This abundant North American genus is represented 
in Illinois by three native species. The workers are 
usually pale yellow, generally with a dusky spot on each 
side of the gaster, and range in size from 1.5 to 3.5 mm. 
They nest in a variety of places, including under rotten 
wood, under bark, in acorns, and under stones, each nest 
containing at most a few hundred workers. They are 
general scavengers, foraging in ground litter and low 
vegetation. Although their nests may frequently be 
found in the garden, they very seldom enter the house. 
SELECTED REFERENCES 
Back, E. A. 1946. House ants. U.S. Department of Agriculture 
Leaflet 147. 8 p. 
Brown, Wiuuiam L., Jr. 1948. A preliminary generic revision 
of the higher Dacetini (Hymenoptera: Formicidae). Ameri- 
can Entomological Society Transactions 74: LOTS 129% 
Buren, Wituiam F. 1944. A list of Iowa ants. Iowa State 
College Journal of Science 18:277-312. 
Core, ArTHuR C., Jr. 1968. Pogonomyrmex harvester ants: 
A study of the genus in North America. University of 
Tennessee Press, Knoxville. 222 p. 
CREIGHTON, WILLIAM STEEL. 1950. The ants of North Ameri- 
ca. Bulletin of the Museum of Comparative Zoology 
104:1-585; 57 plates. 
