316 NATURAL HISTORY OF ARTHROPODS. 



thorax with two roiuul, bhick spots each side of the micldlc, ami dull yellow elytra 

 with siitural ami marginal l)lack line from their bases to their tips, and a blaek line 

 extending from the base to near the tip uj)on the middle of each elytron. This species 

 is dull red with black markings beneath. CEi7ioiii/chis diffei-s from Disonycha in hav- 

 ing the last joint of the posterior tarsi globosely inflated at the tip. CEJioiiycliis 

 </io«<t'tea has deep blue elytra, yellowish head and epipleurie; eyes and anleniue are 

 black, and the yellowish prothorax bears a few blaek spots. Jikpliarkia r/ioiti is a yel- 

 lowish beetle above with brown blotches on the elytra, which latter are also jiunctate 

 with dark brown dots. The eyes, antenn<e, legs, and umler side of the abdomen are 

 dark brown. Its length is about 0.25 inch ; its antenna- are set wider apart than in 

 most flea-beetles, resembling, in this respect, Chrygomi-Ja, from which it is readily dis- 

 tinguished by its thickened thighs. Its eggs are deposited, five or six together, 

 beneath pellets of its excrement. Its yellowish larva which is, like the beetles, abund- 

 ant on leaves of sumach (lihuti), covers itself with its own excrement by means of its 

 extensible anus. The larva is broader than the larvie of other saltatorial Chrysome- 

 lidffi, thus aj>jn-oaching the form of larva in the genus Chrysoinda. 



Structurally sitiiilar to the larger flea-beetles, and like them having the antenna 

 set in close approximation between the eyes, but separated from them by their slender 

 femora, are the genera Dlabrotlca and GaJerucu ; the species of the former genus 

 have a carinate front, while those of the latter have a flat front with an impressed 

 median line. 



Galeruca xanthomehena is a species introduced into America from Europe, accord- 

 ing to Townend Glover, as early as 1837, and does considerable damage to the elm in 

 both countries. The beetle is about 0.25 inch long, oblong, l)rownish yellow or vel- 

 low, marked with black as follows : one or two spots on the head, three on the pro- 

 notum, and, on the elytra, a very narrow sutural line, outside of which, on each side, is 

 a broad strijie not I'eaching tlie apices of the elytra. The yellow, oblong-oval eggs 

 are dejiosited on the under side of the leaves in groups of from three to twenty or 

 more. The egg state lasts about a week. The larva?, of which the first brood ap])ears 

 in IMay, are nearly cylindrical, yellowish black with black markings; they change their 

 skin three times after lea\ing the egg Itefore jiujiation, thus having four larval stages, 

 whicli last ordinarily about two weeks, but under especially favorable conditions only- 

 six or eight days. The ]nij)a is oval, with a few consj)ic>uius black bristles, and is 

 found in crevices of bark or of the ground, or on the ground beneath leaves. The 

 pupal state requires from six to ten days. There are three or four broods yearly, 

 according to climate. The beetles of the last In-ood hibernate, and the few survivors 

 of tlie winter lay the eggs for the first brood early the next sjiring. Both larv;e and 

 imagos feed ujton the elm, jiartly skeletonizing its leaves, Ijut of course tlie greater 

 part of the damage is done by the larviE. Each successive brood is usually larger and 

 more destructive than the jjreceding one, but the majority of the last T)rood each year 

 is killed by the frost of winter. In Austria the larva, as well as the imagos, are said 

 to hibernate. Dr. C. V. Riley, who has investigated this species in Washington, D. C, 

 writes of its enemies: "Among these there are Platymts punctiformis a.n<\. Quedius 

 molochiniis, which feed on the full-grown larva' when these retire for ])upation, and 

 also on the pupa?. The larva of a C/irysopa (probably C. rujilah-is) feeds u])on the 

 eggs of the Galeruca ; Beduvius novenarius sucks both beetles and larvae on the leaves, 

 while 3/antis Carolina ])reys U]wn the beetle. Of the numerous other insects found 

 among the jjupa^ under the trees, e. </., TachyporuK jocosus, sundry spiders, myria- 



