78 IOWA STUDIES IN NATURAL HISTORY 
sharp humeral spines which are directed anteriorly. It is more 
particularly a southern species which apparently reaches its 
northern limits, in the Mississippi Valley at least, in central 
Iowa. Osborn records it from Ames (Proc. Ia. Acad. Sci., IV, 
231, 1896) and the eight specimens now in my collection are 
from Hills, Iowa City and Moscow. All were collected between 
August 20 and October 23. 
This insect seems to prefer vegetation growing in soil that is 
somewhat sandy. One specimen was swept from radishes grow- 
ing in. a sandy truck patch. The other specimens were taken 
from weeds growing in sandy and more or less gravelly soif 
along the edges of cultivated fields. Other food plants recorded 
for this species are maize (Zea mays Linn.), panic grass (Pan- 
icum sp.), foxtail grass (Setaria sp.) and wheat. It is also 
carnivorous to some extent and has been reported as feeding 
upon the larvae of the cotton worm (Aletia). 
Genus EUSCHISTUS Dallas 
1851. Evuscuistus Dallas, List Hem., I, 193 and 201 
This is one of the largest genera of the Scutelleroidea and 
contains more than sixty species. It is Nearctic and Neotropical 
in distribution, eighteen forms being recorded from North 
America; of these, five have been taken in Iowa. The members 
of the genus exist under very different environmental conditions 
and are possessed of considerable adaptability. The chief diag- 
nostic characters may be summed up as follows: 
Body ovate. Apex of head rounded or emarginate; central lobe always 
reaching anterior margin of head but it may be longer than or surpassed 
by the lateral lobes; sides of head sinuate near eyes; eyes moderate. 
Ocelli small. Antennae of five segments, the basal segment short, stout, 
never surpassing apex of head; second segment usually shorter than third, 
the third, fourth and fifth segments about equal; antennal tubercles visible 
from above. Rostrum extending to posterior coxae, the basal segment not 
or scarcely reaching base of head. Pronotum with lateral angles prominent, 
sometimes rounded, sometimes acute and spinous; antero-lateral margins 
usually more or less crenulate (these margins are crenulate in all the Iowa 
forms). Scutellum triangular, not extending as far posteriorly as corium. 
Membrane with longitudinal nervures. Venter unarmed. Tibiae suleate 
above. Tarsal segments three, of which the basal one is longest. 
Subgenus Evscuistus Dallas 
1872. Evuscuistus Stal, Svensk. Vet. Handl., 10, no. 4, 26. 
