7 
of this loss undoubtedly can be avoided by a proper system of farm 
management and the adoption of known methods of control. 
The important natural agencies responsible for the abundance or 
scarcity of this insect are not insect parasites, for if has none of any 
importance, but unfavorable climatic conditions and the various dis- 
eases induced thereby. The chinch bug is notably an accompaniment 
of drought, and very rarely, if ever, is serious injury caused by it in 
other than dry seasons. Wet weather is very prejudicial to it and 
develops various fungous diseases, which as a rule very promptly 
result in its practical extermination for the season. Unfortunately 
these weather conditions are not subject to control, and the chinch bug, 
therefore, is bound to be in evidence in dry years. It then becomes a 
matter of attention to whatever practical farm methods are available 
to prevent greater loss than necessary. 
Distribution—The chinch bug is a native 
insect, originally subsisting on various wild 
grasses in the Mississippi Valley and through- 
out its range. On this continent it is widely 
distributed (fig. 2), occurring from Nova Scotia 
and Manitoba southward to the Gulf. It 
occurs also in California, Lower California, 
-and in Mexico and Central America, and also 
on several of the West Indian Islands. Over 
much of this areait is not often very injurious, 
and the chief losses occasioned by it are in 
the Ohio and Upper. Mississippi Valley and : EAL 
lake region, and, to a less extent, northeast- form, much enlarged (from 
ward throughout the Allegheny region, New “°": 
England, and Nova Scotia. The Gulf States do not so often suffer 
serious injury from this insect, except occasionally, perhaps, in the 
rice-growing regions. 
The losses resulting from the chinch bug are largely to the wheat 
crop, and it is one of the most important wheat pests. The losses to 
corn are almost always a result of migrations from wheat fields after 
harvest. The losses to grasses are less noticeable, although in some 
‘ases quite important. 
Attention was first drawn to its ravages in the latter part of the last 
century, and the records of notable outbreaks and serious loss have 
been pretty constant since 1800.“ 


«A matter of no especial importance is the fact that along with the ordinary chinch 
bug, which is winged and capable of strong flight in the adult stage, there frequently 
occurs, especially in maritime districts, both of the Atlantic coast and the Great 
Lakes, a short-winged form (fig. 3), the wings of which vary from almost nothing 
to nearly full size. This short-winged form is associated with the normal type, and 
has the same habits except that it is not capable of flight. So far as the practical 
consideration of this species is concerned, the short-winged form may be ignored. 
182 
