is FARMERS’ BULLETIN 657. 
(See map, fig. 7.) So far as the influence of temperature is concerned, 
it is only in the most unprotected situations that severe winter 
weather appears to have much effect in regulating the abundance 
of the pest, although frequent freezing and thawing is known to be 
Fie. 7.—Map of North America showing areas infested by chinch bug. (Author’s illustration.) 
fatal to a large percentage of the adults if these occur in exposed 
situations. Thus temperature may practically be elimimated from 
consideration. It is also true that the nearly developed insect will 
withstand not only the humidity of the Tropics, but continuous 
drenching rains of more northern latitudes, It is at the time of 
