THE STATE ENTOMOLOGIST. 19 



insect, and the little creature never quits eating as long as the warm 

 weather lasts, except for a day or so while it is accomplishing each 

 of its successive three, four or five moults. As the Chinch Bug be- 

 longs to the Half-winged Bugs, it therefore continues to take food, 

 with a few short intermissions, from the day when it hatches out 

 from the egg to the day of its unlamented death. 



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

 require 12 months to go through the complete circle 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 bivittata, Say) 

 and the White Grub which produces the May-beetle (Lachnosterna 

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

 tredecim, 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 same 

 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 

 (Cecidomyia 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 iour-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 (Aphis) 

 produce an indefinite number ot 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, 1866, 1 published the fact that the Chinch 

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

 43), 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 North- 

 ern 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, (Clostcra Americana, Harris), is 

 stated by Dr. Harris and Dr. Fitch to be only single-brooded in Mass- 

 achusetts and New York, the insect spinning up in September or Oc- 

 tober, passing the winter in the pupa state, and coming out in the 

 winged form in the following June. But Dr. Harris — no doubt on the 

 authority of Abbott — states that "in Georgia this insect breeds twice 

 a year ;"* and 1 have proved that it does so breed in Missouri, having 



^Injurious Insects, p. 434. 



