314 NATURAL HISTORY OF ARTHROPODS. 



in cases ami mines, or not noticed hy birds on account of their minuteness; as a result 

 of tliis immnnity from attack species of Chrj'somelida' often become serious pests^as 

 is the case witii tlie Colorado potato-beetle. 



The jiupal state is passed, as a rule, as follows: uudiTuround, often with sliuht 

 cocoon, by the first half of the larv;e mentioned in Laeordaire's second group, and bv 

 some of those of his third and fourtli grou])s ; under water in a cocoon attached \fi - 

 stems of water-]ilants, by species of his first group; in the leaf-mines by some species'* 

 in his third grouj) ; upon leaves by the second half of his second group, and by most 

 of his fourth group ; and in larval cases by the s]iecies of his Kfth group. 



Entomologists usually divide the Chrysomelida; into tribes, divisions which, to a 

 certain extent, coincide with the groups of larvaa before mentioned, but forms of espe- 

 cial interest will be discussed liere in their systematic order, without further sub- 

 division of the family. 



Sj)ecies of Cdnsida and allied forms are recognized by the e.vcessivelv wide margins 

 of the [irotliora.Y anil elytra, and by the head being partly or -wholly coi)ceale<l beneath 

 the forward margin of the jirothorax, the whole insect thus ])resenting a flattened, 

 roundish, scale-like asjiect. Among tropical .sjiecies very brilliant coloration is found. 

 Dcsmonota I'ariolosn is a round metallic-green siiecies from Soutli 

 America, not rarely seen set in jewelry ; its elytra are .so hard as to 

 resist the point of a slender jiin. J/esoit/jJialia co»sjtersa, another 

 Siiuth American sjiecies, which has an elevated jirotulierance formed 

 by the anterior ))art of the elytra, is dull metallic blackish green, 

 f with velvety black in round jiunctures, and with six hirger spots 



Fig. 3o1. —Mesom- fjj.|j gj^o^y r^^ liurnished gold tlirough a downv ijubcscence. Many 

 of our own species which resemble (_'(it<xhlit, feed upon jilants of the 

 potato family (Sohmaren-), upon the swect-jiotato {IpoiiKea batatax), and others 

 of the morning-glory family (i'oiii'olrtilacen). Coptoci/c/a uiirlrlidlfcit, found on 

 the wild morning-glory, is ln-illiant gold-color, which is said lo vary in shade with 

 the emotions of the animal, and which disappears when the insect dies. The larva 

 of. this s|)ecies was long ago described by T. W. Harris, and later by Di\ C. V. 

 Tiilev ; the latter added a ilescri|iti()n of the egg. The egg is about (I.fl4 of an 

 incli long, of rather irregular angular form, flat, and nsuallj^ furnished with spine-like 

 ajijiendages. They are laid singly upon the leaves of the food-plant of tlie larva. 

 The lar\a is flat, oval, ilark brown, with a paler shade upon the liaek, and is margined 

 witli a row of branched sjiines ; while, by means of its anal fork, it carries over its 

 back, as protection from pre<laceous animals, a jiarasol made of it* own molted skins 

 and excrement. Pu]iation takes jdace in a sjiiny, flattened pupa which is attached to 

 the leaves of the f(»>d-]ilant bv a stickv secretion. Unlike the pu]i;e of most beetles, 

 this one iloes not ha\(' its legs free, althout;li it can raise itself u]i at will, ]ier|iendicu- 

 larly to the surface on which it !■< attached. I'lie tir>t brooil of beetles emerge from 

 their pu]i.-e about July, 1ki\ iii'^' underi;'one their metamorjilioses in a few weeks, and lay 

 the egus for a fall brood. 



VopUx-ijcla clavaUi, a conmion ]>otato-beetle in Xew England, is very dark bi-own, 

 with thin j-ellow margin, the trans])nrcncy of which is interriij>led by a dark brown 

 ])atcli at the anterior extremity of, and another just behind, the middle of each elytron, 

 giving the lieetle a curious tiu'tle-like appearance, in fact the resemblance of s])ecies of 

 CuKsida and ( 'tij/(oci/ch( to turtles has given them the common nanu' of 'tortoise- 

 beetles.' 



