﻿OF THE STATE ENTOMOLOGIST. 2T 



nished Plant Bug (Capsus ohli7ieatus S^y}^ which, as may be seen 

 from my second report, (p. 114), really has such an omnivorous habit. 

 Though, therefore, the subject of our present sketch is restricted ta 

 certain families of plants, yet it manifests a decided preference for 

 some of the grains over others. Thus it shows a great predilection for 

 Hungarian grass ; while of the more important cereals it is most 

 severe on spring wheat and barley. 



MODE OF REPRODUCTION AND HIBERNATION. 



"Most insects — irrespective of the Order to which they belong — 

 require 12 months to go through the complete cycle of their changes^ 

 from the day that the egg is laid to the day when the perfect insect 

 perishes of old age and decrepitude. A few require 3 years, as for 

 example the Round-headed Apple-tree Borer (Saperda hivittata Say) 

 and the White Grub which produces the May-beetle {Laohnosterna 

 quercina Knoch.) One species, the Thirteen-year Locust ( Cicada 

 trcdecim Riley), actually requires 13 years to pass from the egg to 

 the winged state ; and another, the Seventeen-year Locust {Cicada 

 septemdecim Linn), the still longer period of 17 years. On the other 

 hand there are not a few that pass through all their three states in a 

 few months, or even in a few weeks ; so that in one and the sama 

 year there may be 2, 3 or even 4 or 5 broods, one generated by the 

 other and one succeeding another. For example, the Hessian Fly 

 iCecidomi/ia destructor Say), the common Slug-worm of the Pear 

 {Selandria cerasi Peck), the Slug- worm of the Rose {Selandria rosce- 

 Harris), the Apple-worm and a few others, produce exactly two gen- 

 erations in one year, and hence may be termed " two-brooded.'^ 

 Again, the Colorado Potato-beetle in Central Missouri is three-brooded,, 

 and not improbably in more southerly regions is four-brooded. Lastly, 

 the common House-fly, the Cheese-fly, the various species of Blow- 

 flies and Meat-flies, and the multifarious species of Plant-lice {Aphidcey 

 produce an indefinite number of successive broods in a single year, 

 sometimes amounting, in the case of the last named genus, as has 

 been proved by actual experiment, to as many as nine. 



"As long ago as March, 1S66, I published the fact that the Chinch. 

 Bug is two-brooded in North Illinois {Practical Entomologist^ I, p. 

 48), and I find that it is likewise two-brooded in this State, and most 

 probably in all the Middle States. Yet it is quite agreeable to anal- 

 ogy that in the more Southern States it may be three-brooded. For 

 instance, the large Polyphemus Moth is single-brooded in the Northern 

 and Middle States, and yet two broods are sometimes produced in- 

 this State, while in the South it is habitually two-brooded. Again, the 

 moth known as the Poplar Spinner {Clostera Americana Harris), is 



