SCUTELLEROIDEA OF [OWA 13 
by these bugs. More detailed and specific data on feeding habits 
and foot plants of various Iowa pentatomids are included in the 
discussions farther on in this paper. 
Most of the pentatomids are taken by beating vegetation of dif- 
ferent sorts with a sweep net. Cultivated or semi-cultivated 
areas offer better collecting grounds than do wild, uncultivated 
areas. Roadsides, fence rows, margins of grain and hay fields, 
the edges of woods—these are most productive of specimens. 
The cydnids are usually found in more or less sandy places in 
or near the ground on low vegetation. Thyreocorids are found 
usually on small cultivated or semi-cultivated plants and often 
in more or less moist situations. The scutellerids are more 
typical of open prairie country and are found in greatest 
abundance in the western portion of the state. Some of 
the Seutelleroidea hibernate under sticks, leaves, grasses, rocks, 
ete. during the winter months and a few forms have been found 
in practically every month of the year. 
When any difference in size between the sexes prevails—a com: 
mon occurrence—the female is usually the larger. However, 
considerable variation in size is met with among individuals of 
both sexes of a given species though usually within fairly definite 
limits. 
Phalanx PENTATOMIFORMES Reuter 
Only the present group of the three into which the Scutel- 
leroidea is divided is found in North America. The principal 
diagnostic characters of this division are as follows: 
Body below convex or flattened. Rostrum inserted beneath or near apex 
of clypeus, seldom on basal half of gula, in which case the veins of the 
membrane begin near the interior basal angle. Mesostethus reaching sides 
of body, truncate externally and completely separating the pro- and meta: 
stethus. Sides of prothorax retrorse, not produced; meso- and metanota 
concealed. Hemelytra not folding; corium entirely coriaceous, reaching 
side of body near base and appearing as an epipleuron; not surpassing 
apex of abdomen and not prolonged beside the outer margin of the mem- 
brane; veins of membrane supple, often reticulate, never pectino-radiate. 
Connexivum horizontal or slightly declivous. Tarsi of three segments, rare- 
ly of two segments, in which event the scutellum is much narrower than 
the abdomen. 
