46 



THE AMERICAN ENTOMOLOGIST. 



entering upon a multiplicity of details we shall 

 enumerate only ten distinct species. Ilitherto 

 it has been supposed that there was no parasitic 

 insect whatever, that preyed internally upon the 

 larva of tliis Potato-bug ; but we have ourselves 

 bred from these lai-vae a parasitic two-winged 

 fly (Tachina family, Fig. 35), the peculiar habit 

 [Fig. 35.] of which is to 



attach its egg 

 externally to 

 the body of its 

 - li\hiS victim; 

 ^^ \\ lii( heggsub- 



^( (|UC'utly hat- 

 clie-. out, bur- 

 row'' into the 

 body of the in- 

 fested lai-va, 

 and eventually 



Colors— Grny, black, and sUveiy wliite. deStVOyS 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 Ladybird (Ilipjioda- 



cris.sc.] 



Colors - FiDk Colors - Brick Colors - Brick 



and black. '^'^i black and red, black and 



7nia maculata, DeGeer, Fig. 36), the nine- 

 marked Ladybird (Coccinella d-notata, Herbst, 

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

 daniia Vi-pimctata, Linn., Fig. 38), and the 

 convergent Ladybird {Hlppodaniia convergens, 



[Fig. 39.] 



Guer.) TMs last species, 

 the three stages of which 

 are represented of the 

 natural size, in Fig. 39 

 (« the larva, b the pupa, 

 and c the beetle), is ra- 

 ther a rare insect in 

 North Illinois, though 



•Dr. Wm. LeBaron, of Geneva, 111., who li.-is made the 

 study of this order a sijeciality, kindly informs us, that this 

 fly belongs to the genua (or sub-genus) Zydella, Macquart. 

 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 b), wliioli is attached 

 to the leaves of the x'lant upon wliich the lai-va 

 has lived, might be readily mistaken for that of 

 the Potato-bug larva. The larvaj 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 « 

 and 40 will give a sufficiently good idea of tliem 

 all. They run with considerable speed, and 

 may be found in great numbers 

 upon almost all kinds of herbage. 

 The larvaj of certain species that 

 prey upon the Hop Plant-louse in 

 the East are well known to the hop- 

 pickers as " black niggers " or " ser- 

 pents," and are carefully preserved 

 Coior^Biackand ^i' ^^^^^ "^ some of their most effi- 



oranse. clcut fricuds. 



The eggs of Ladybirds greatly resemble those 

 of the Colorado Potato-bug, and are scarcely 

 distinguishable except b)' their smaller size ami 

 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 persons who undertake to destroy the latter, 

 not^to confound those of their best friends with 

 tho.se of their bitterest enemies. 



In the larva state the Colorado Potato-bug is 

 extensively depredated on, both in Illinois, 

 Missouri and Iowa, by the Spined Soldier-bug 



n 



ownaudspeck- 

 ttnd yellow. 



(Arma spinosa, Dallas, Fig. 41 b). Thi-usting 

 forwards his long and stout beak, he sticks it 

 into liis 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 (Scutellera family) of the true bugs 

 {Ileteroptera) , distingviishable from all others 

 by the very large scutel, wliich in tliis genus is 

 triangular, and covers nearly half liis back. 

 Most of the genera belonging to tliis group are 

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

 rosires) to wliich our cannibal friend belongs, 

 characterized by the robustness of their beaks, 

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

 tends, are caimibals. To illustrate to the eye 



