348 NATURAL HISTORY OF ARTHROPODS. 



this pseudu-jaijiu. Jii this pseuJu-]>iij):il state hiljeruation takes jihiee, and the next 

 spi'ing the pseiido-piiija bursts oj)en, and the third larva apijears. This larva, which 

 otherwise closely resembles the scarab.eidoid form before mentioned, has rudimentary 

 mouth-parts and poorly developed, two-jointed feet. After about two weeks, durins^- 

 which time this third lar\a dties not leave the cavity in which it emerged from the 

 pseudo-pupa, it changes into a normally formed beetle-])ujia, and in about twenty days 

 more the beetle apjiears. 



JIj)icauta cirierea, E. peitsijlcunlua, and ^fucrobasis tDikolor eat potato-leaves as 

 imagos, but as larvaj they are useful to man by destroying locusts. Tlie Rockj- Mountain 

 locust lays its egg-masses just beneath the surface of the ground, and these sjaecies of 

 Ejytcauta oviposit near the locust eggs, in a hole which the female Ei/lcauta digs for the 

 purpose, afterwards covering her egu's by scratcliing dirt over them with her feet. The 

 eggs hatch in about ten days, and the light brown triungulins, if the 

 weather is warm, soon Ijegin searcliing out locust eggs f(_)r foo<l ; if it is 

 cold Aveather they remain closely huddled together until warmth induces 

 acti\ity. Dr. C V. Riley observes: " Should two or more triungulins 

 enter the same egg-pod, a deadly conflict sooner or laler ensues until 

 one alone remains the victorious possessor." ^Vftcr devouring about 

 two eggs, that is, at the end of ab(.jut eight days after beginning to 

 feed, a moult takes ]ilace, and the second larval form ap|)ears, the /oi-m 

 Fig. 390. — £7);- desio-nated as carabidoid. The carabidoid form lasts about a week, the 

 succeeding scaraba'idt)id form about a week ; after reaching the ultimate 

 Stage of the second larva, it feeds about a week, then leaves the renniants of the 

 locust's egg-mass, and ri)un<ls out for itself a smooth cavity in the ground. After 

 being in this cavity about tV)ur days, a moult takes place, but the skin is not entirely 

 shed. The soft skin <juickly hardens, and the insect is now a pseudo-j)upa. After 

 hibernating as pseudo-jjujia, the skin again luirsts, and the thinl lar\ a ajipears. This 

 third larva burrows about in the ground, and in a few days the true jiujia is formed, 

 from which, in live or six days, the imago appears. The functional significance of the 

 third larva, wliieh, in these insects as in J^ytta reslcatorin, e.ats notliiiig, is not Net 

 understood. 



The genus Mi/hibr!s includes over two hundred and fifty beetles in which the 

 elytra cover the entire abdomen, the mandibles are short, the antenna^, are gradually 

 enlarged toward the apex. The species are often black or blue-black, banded with yellow, 

 and of consideralile size. Xo true JL/labri.s is found in the United States. Con7i//os- 

 2Jasta fullei-i from Xe\'uda, with eight-jointed antenn;e, is an allied form to JLyhtbris. 



tSitaris differs from Jfi/liibris in having wings jjartly exj)osed, and the rudimentary 

 elytra narrowecl rapidly beliind, and not reaching the tip of tlu' abilomen. The 

 first to describe all the different stages of any .species of Meloidic was J. H. Fabre, 

 who, in 1857, published his account of the metamorphoses of t^itdi-in /i)/i/ieriilis, a 

 French species, whicli is j)arasitic on bees of the genera AiithopJiont and Jjonihus. 

 Fabre's account of the life history of S. Inavemlis is briefly given as follows: The 

 males and females, as soon as they have emerged from the ]iu]i;e, ]iair in the subter- 

 ranean nests of the bees upon which tlicv are jiarasitic, and the female lays soon 

 after about two thousand eggs, near llie entrance of the nest. Tlie triungulins, which 

 hatch in about a month, hibernate, without feeding, among their egg-shells, and the 

 next spring attach themselves to the hairs u])on the thorax of the male liees, fi'om 

 which they jirobably pass over to the females during the ])airinL; of the bees. Thus 



