194 



THE AMERICAN ENTOMOLOGIST. 



THE CHINCH BUG. 



(Mic7'opus leucopterus, Say.) 



[ COKCLUTJED FKOM >TJMBKE NIKE, ] 



Cannibal Foes of the Chinch Bug. 

 As long ago as 1861, the Senior Editor, in his 

 Essay upon the Injunous 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, 

 DeGeer, Fig. ISo), -wliich also preys upon a 

 great variety of other ipsects, attacking both the 

 [Fig. 135.] eggs of the Colorado [pjg. 3.3c.] 



Potato Bug and those 

 V f^^i^ T °^ certain Bark lice ; wSev^ ^ 



and which is further Vf 



remarkable for being 



mpp. maculata. on^ of the few insects <'""• """"'«• 



color.. pi„k and fonnd both iu Europe c°i;;,"^^'si;tbrick 



"'"''■ and in North America. •'''"=''• 

 The second is thO' Trim Ladybird (Coccinella 

 munda, Say, Fig. 136), 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 iiisects, belong- 

 ing to a genus {Scymmis) of Ladybirds, most 

 of the species of which are quite small and of 

 obscure brown colors, and hard to be distin- 

 guished by the popular eye from other beetles, 

 the structure of which is very diflerent, and 

 which therefore belong to very different groups 

 and have very ditferent habits. Of these last 

 we present no figures; as the scientific reader 

 knows perfectly well by what characters they 

 can be recognized, and no mere figures would 

 enable the popular reader to recognize them at 

 a glance , 



In the autumn of 1864 Dr. Shimer ascertained, 

 apparently by actual observation, that the very 

 same Ladybird which has been sketched above 

 (Fig. 135) preys extensively upon the Chinch 

 Bug. Iu a particular field of corn, which had 

 been sown thick for fodder, and which was 

 swarming with Chinch Bugs, 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." On the general subject of Ladybirds 

 and their lizard-like larvae, we must refer the 

 reader to what we have said in our article on 

 Potato Bugs (No. 3, p. 46), where figures of 

 iieveral species in their diflfereut stages will be 

 und. 



*SeeTro)!S. III. St. Agric. Society, IV, pp. 346-9. 



In the same autumn the same observer made 

 the additional and entirely original discovery, 

 that iu the very same field of fodder-corn the 

 Chinch Bugs were preyed upon by the larva of 

 a very common species of Lacewing Fly — the 

 "Weeping Lacewing (Chrysopa plorabunda, 

 Fitch.)* "With the exception of the Eyed Lace- 

 Aving (C'/jr. oculata, Say), and perhaps the Red- 

 lipped Lacewing (C'kr. rufilahris, Burm.), this 

 is our commonest species iu Illinois ; and Dr. 

 Fitch says that he met with it in abundance in 

 the very months, September and October, in 

 which Dr. Shimer noticed it in such profusion 

 in a corn-field, and not only in his own State, 

 New York, but also in the State of Illinois. All 

 the Lacewing Flies, however, resemble one 

 another so closely both in size, shape and color, 

 that the ordinary observer would suppose them 

 all to belong to the same species ; and the same 

 may be said of their larvre. Hence we shall 

 merely repeat here from page 33 the figures 

 there given of one of them, where a represents 



[Fig. 137.] 



the eggs, b the larva with its long sickle-shaped 

 jaws, by which it may be readily distinguished 

 from all the Ladybird larvas, .c the ridiculously 

 small cocoon, and d the enormous fly that comes 

 out of this ver}^ small cocoon, as the Bottle- 



* Dr . Shiraer has rc-clescribed plorabunda as a new species 

 under the name of illinoiensis in Proc . Ent. Soc. Phil., IV, 

 p. 208. He favored us some years ago with five siiecimens of 

 this so-called new species of his, which exp.and Jrom 0.93 to 

 1.0.5 inch. He himself states it to expand from 1.02.5 to 1.08 

 inch, and says that it difl'ers irom plorabunda in the "larger 

 size," Fitch giving "1 inch" as the expanse of that , 

 species! So tha1;by his own showing the average dilference \ 

 in the expanse, which is to form one of the reasons for gi-ind- \ 

 ing out a new species, is only about Jive-hundredth.i of an 

 inch! This is certainly pretty line wire-dr.awing! The other 

 differences that he points out are equally lutile. For exam- 

 ple, this species has the wings as much rounded at tip as any 

 Chryi,opa known to us, though the tip of each wing and espe- 

 cially of the hind wing is still very slightly augulated. 

 Now, plorabunda is very properly described by Fitch as 

 having ' ' the wings rounded at tixjs, the bind pair slightly 

 angular ; ' ' and in comparison with such species as intfilabris, 

 Burm. , it may well be said to have roimded wings, though 

 sti'ictly speaking the typical obtuse angle can still be ob- 

 scurely seen at the tip even of the front wmg. Hereupon Dr. 

 Shimer remarks that his so-called new species * ' differs from 

 plorabunda iu having the anterior wings, as well as the pos- 

 terior, a little acuminate. ' ' We shoiild like to see a Chrys- 

 opa where they are not more or less acuminate! As another 

 glaring proof of the scientific unreliability of this writer, 

 upon any question of classification, we may add that he 

 asserts that his illinoiensis differs. from Harrisii, Fitch, "in 

 having no black nervures," (p. 212). Now, Harrisii is ex- 

 pressly stated by Fitch to have the nervures "greenish 

 white without any traces of dark green or black at their 

 ends. ' ' (iV. T. Rep . , I, p. 90) . How then is it possible for 

 illinoiensis to differ from Harrisii by having no black ner- 

 vures, when neither species has black nervures? 



