THE STATE ENTOMOLOGIST. 25 



very great numbers, was almost annihilated in the course of the 

 summer, it perished, not as others had foolishly supposed, from the 

 direct operation of the rain, but indirectly through a certain myste- 

 rious epidemic disease analogous to the Cholera or the Yellow Fever 

 among human beings. He fully allows that the mortality among the 

 Chinch Bugs was contemporaneous with the wet weather; but he 

 will have it that it was not the wet weather that killed the Bug, 

 as we common folks have always hitherto believed, but that 

 it was his newly-discovered Epidemic Disease. But as in the con- 

 joint article in the American Entomologist (I, pp. 174-6) this Epi- 

 demic theory was fully considered by my late associate, Mr. Walsh, 

 in his own peculiar style, I shall not dwell upon it here. 



CANNIBAL FOES OF THE CHINCH BUG. 



As long ago as 1861, Mr. Walsh, in his Essay upon the Injurious 

 Insects of Illinois, published facts which tended to show that four 

 distinct species of Ladybirds preyed upon the Chinch Bug.* The 

 first of these four is the Spotted Ladybird (Hippodamia maculata, 

 [Fi ft . 3.] DeGeer, Fig. 3), which also preys upon a great I F Js- 

 variety of other insects, attacking both the eggs 

 ^T of the Colorado Potato Bug and those of certain T^A ■ I 

 J. Bark-lice ; and which is further remarkable for^ J\^J 



_ one of the few insects found both in Europe and in North 

 America. 



In corroboration of the fact of its preying on the Chinch Bug, 

 I may state, that the Rev. Chas. Peabody, of Sulphur Springs, informs 

 me that he has repeatedly found it so feeding on his farm. The second 

 species is the Trim Ladybird (Coccinella munda, Say, Fig. 4), which 

 is distinguishable at once from a great variety of its brethren by 

 having no black spots upon its red wing-cases. The other two are 

 much smaller insects, belonging to a genus (Scymnus) of Ladybirds, 

 most of the species of which are quite small and of obscure brown 

 colors, and hard to be distinguished by the popular eye from other 

 beetles, the structure of which is very different, and which therefore 

 belong to very different groups and have very different habits. 



In the autumn of 1864 Dr. Shimer ascertained that the Spotted 

 Ladybird which has been sketched above, preys extensively upon the 

 Chinch Bug. In a particular field of corn, which had been sown thick 

 for fodder, and which was swarming with Chinch Bngs, he found, as 

 he says, that this Ladybird, "could be counted by hundreds upon 

 every square yard of ground after shaking the corn ; but the Chinch 

 Bugs were so numerous that these hosts of enemies made very little 

 perceptible impression among them." 



In the same autumn Dr. Shimer made the additional discovery, 

 that in the very same field of fodder-corn the Chinch Bugs were 

 preyed upon by a very common species of Lacewing-fly, which he 



*See Trans. III. St. Agric. Society, IV, pp. 346-9. 



