ENTOMOLOGY 183 



molt results in the perfect insect. Nearly two months are required 

 to complete this life cycle. 



After hatching the chinch bug is extraordinarily active in all 

 stages, even the minute larva being able to travel rapidly and to ex- 

 tract itself from a considerable depth of covering soil if necessary. In 

 habits this insect is distinctly gregarious, associating itself in masses 

 on the plant attacked, commonly going by preference to the lower 

 portions of the plant and, in the early larval stage, even working on 

 the superficial roots. 



The first brood is normally developed in wheat land, for the 

 simple reason that when the chinch bug takes its spring flight w r heat 

 is the growing crop which is most likely to attract it. The wheat crop 

 matures and is harvested, as a rule, before the first brood of bugs has 

 reached maturity or at about the time they are entering the adult 

 stage. The ripening and harvesting of the grain deprives them of 

 food and induces a migration, and the young, half-grown, and adult 

 insects start off together, apparently with a common impulse, aban- 

 doning the wheat fields and attacking any near-by cornfield or grass 

 field. Their travels, while commonly much less, may extend to a dis- 

 tance of a quarter of a mile or more, and, as a rule, under these cir- 

 cumstances the bugs are numerous enough to completely carpet the 

 ground. Entering a field of corn, they congregate on the outer rows 

 at first, fairly blackening the stalks with their bodies and absolutely 

 killing the corn as they move inward. As a rule, the serious damage 

 is on the edge of the cornfields, sometimes, however, extending in- 

 ward several rods. 



If this midsummer migration is not induced by the harvesting 

 of grain, or where the chinch bugs develop in other situations, their 

 reaching maturity is immediately followed by midsummer flight to 

 corn or millet or other crop. 



Curiously enough, in the migration above noted the winged in- 

 dividuals, as well as the wingless, all crawl together on the ground, 

 and flight seems never to be attempted on the part of the adult. The 

 second brood, maturing about the last of August and the first of Sep- 

 tember, may have a partial flight to late corn or other late crops if 

 the cornfields in which they develop have already matured and are 

 drying up, but between the middle of September and the first of Octo- 

 ber they take \yhat may be termed the autumnal flight to grass lands 

 or other situations for concealment and hibernation. 



For the practical control of the chinch bug many suggestions 

 have been made, some of which have a good deal of utility. These 

 are considered in the order of their importance. The hibernating 

 habit of the chinch bug suggests at once the advisability of burning 

 over and clearing up all waste land where this insect would be apt to 

 congregate for overwintering. The burning of grass lands, especially 

 the wild grasses which may have the stooling habit, should be done 

 early in the fall so as to expose the chinch bugs that may not bo 

 killed by the flames as long as possible to the unfavorable action of 

 the cold and freezing of winter. All the rubbish in the fence corners 

 and hedge rows should be raked out and burned and as little mate- 



