46 



THE AMEEICAH ENTOMOLOGIST. 



entering upon a multiplicity of details we shall 

 enumerate only ten distinct species. Hitherto 

 it has been supposed that there was no parasitic 

 insect whatever, that preyed internally upon the 

 larva of this Potato-hug ; but we have ourselves 

 bred from these larvae a parasitic two-winged 

 fly {TacMna family, Fig. 35), the peculiar habit 

 [Fig. 35.] of wliich is to 



attach its egg 

 externally to 

 the body of its 

 living victim; 

 which egg siib- 

 seqviently hat- 

 ches out, bur- 

 rows into the 

 body of the in- 

 fested larva, 

 and eventually 



Colors— Gray, Mack, and silvery white. destrOyS it, but 



not until it has gone under ground in the usual 

 manner. The important and extensive family 

 to which this two-winged fly belongs has hith- 

 erto been so little attended to by North Ameri- 

 can Entomologists, that we can not satisfacto- 

 rily identify it with any of the few described 

 species, and for the same reason we prefer not 

 to name and describe it as a new species.* 



In the egg state the Colorado Potato-bug is 

 preyed upon by no less than four distinct species 

 of Ladybirds — the spotted Ladj'bird {Ilippoda- 



CFig: 37.] 



[Fig.SS.] 



Colors— Pink Colors— Brick Colors — Brick 



and black. red, black aud red black and 



whit? . wnite. 



mia maculata, DeGeer, Fig. 36), the nine- 

 marked Ladybird {Coccinella 9-notata, Hcrbst, 

 Fig. 37), the thirteen-dotted Ladybird (Ilippo- 

 damia li-punciata, Linn., Fig. 38), and the 

 convergent Ladybird {Hippodamia convergens, 

 Guer.) Tliis last species, 

 the three stages of which 

 are rexDresented of the 

 natural size, in Fig. 39 

 (a the larva, b the pupa, 

 and c the beetle), is ra- 

 ther a rare insect in 



"'etbirckaJdwhite^'"' North imiiois, thoUgh 



Colors— (a) blue, orange and black 



w 



*Dr. Wm. LeBaron, of Geneva, 111., who has made the 

 study of this order a speciality, kindly informs lis, that this 

 fly belongs to the genus (or suh-genus) Zydella, JMaoquart. 

 He says "it is very closely allied to Tachina proper, and 

 could properly be united with it, did not the great number 

 of species require a division as a matter of necessity . ' ' 



it is common enough in South Illinois and Mis- 

 souri. Its pupa (Fig. 39 &), which is attached 

 to the leaves of the plant upon winch the larva 

 has lived, might be readily mistaken for that of 

 the Potato-bug larva. The larvje of all these 

 Ladybirds are far more bloodthirsty in their 

 habits than the perfect beetles ; and as they all 

 have a strong general resemblance. Figs. 39 a 

 and 40 will give a sufficiently good idea of them 

 all. They run with considerable speed, and 

 [Fig. 40.] may be found in great numbers 

 upon almost all kinds of herbage. 

 The larva3 of certain species that 

 prey upon the Hop Plant-louse in 

 the East are well known to the hop- 

 Ijickers as "black niggers " or " ser- 

 pents," and are carefully preserved 

 by them as some of their most effi- 



orange. ^.Jg^^ fricuds. 



The eggs of Ladj^birds greatly resemble those 

 of the Colorado Potato-bug, and are scarcely 

 distinguishable except by their smaller size and 

 by a much smaller number being usually col- 

 lected together in a single group. As these 

 eggs are often laid in the same situation as those 

 of the potato-feeding insect, care must be taken 

 by i^ersons who undertake to destroy the latter, 

 not; to confound those of their best friends with 

 those of their bitterest enemies. 



In the larva state the Colorado Potato-bug is 

 extensively depredated on, both in Illinois, 

 Missouri and Iowa, by the Spincd Soldier-bug 



[Fig. 41.] 



[Fig. 42.] 



(Anna spinosa, Dallas, Fig. 41 &) . Thrusting 

 forwards his long- and stout beak, he sticks it 

 into his victim, and in a short time pumps out 

 all the juices of its body and throws away the 

 empty skin. He belongs to a rather extensive 

 group {Sciitellera family) of the true bugs 

 {Heterop>tGra) , distinguishable fi-om all others 

 by the very large scutcl, which in tliis genus. is 

 triangular, and covers nearly half his back. 

 Most of the genera belonging to tliis group are 

 plant-feeders, but there is a sub-group {Spissi- 

 rostres) to which our cannibal friend belongs, 

 characterized by the robustness of their beaks, 

 and all of these, so far as our experience ex- 

 tends, are cannibals. To illustrate to the eye 



