TETRA3IER0US PLANT-BEETLES. 



165 



A. La«t joint of palpi widened and truncated ; claws toothed Oksodacna. 



A A. Last joint of palpi not wider than the others and pointed ; claws simple CitiocKius. 



Orsodacna, a name taken from the Greek and meaning a hud-giimrer, 

 was originally api)lie(l to some insect now unknown, which was injnri- 

 ons to fruit trees. It includes three sub-genera: Or-sixhtcna, Latr., having 

 the thorax uniform and the eyes entire ; Zeugnphora, Kun/e, having the 

 eyes notched and the thorax with a lateral tubercle ; and >St/7ieta, Esch., 

 with several short teeth at the sides of the thorax. The si)ecies are of 

 moderate size, and either blackish or dull yellow, but more commonly 

 with both of these colors combine*!. We have twelve species, some of 

 which are very variable, and have been described under dillVrent names. 

 The only species of Crioceris proper found in the United States, is the 

 imjjorted asparagus beetle, Crioceris asparagi, Linn., which has become 

 naturalized in some of the I']astern States. Most of our s])ecies are now 

 placed in the sub-genus Lema, Fabr., as restricted by Lacordaire, and 

 distinguished by having the thorax constricted or narrowed a little be- 

 hind the middle. The most common species is the Lema trilineaia, Oli- 

 \'ier, or the Three-lined potato-beetle, a quarter of an inch long, yellow, 

 with three black stripes on the elytra. Mr. Crotch enumerates twelve 

 other species, most of which inhabit the Southern States. 



Sub-family CHRYSOMELIDES. 



This sub-family is founded upon the typical genus Chrysomela, of Lin- 

 naeus, a word which literally means a golden appJe^ and which was ob- 

 viously given to these insects in allusion to their rounded form and 

 [Fig. 81. J beautiful colors, which not un- 



frequently exhibit a golden hue. 

 Their most distinctive scientific; 

 ,\ character, as compared with th6 

 other sub-families of this tribe, 

 is the distance from each other 

 of the autennie at their i)()ints of 

 attachment, being always farther 

 apart than the length of the first 



Crrysomei.a(myocoryna) JUXCTA. Germar:— a. eggs; • ■ ^ i ^f^p,, f^^ „« flirpft 



bfc, larva;; c, beetle; d, wing-cover ; e, anterior leg- JOl"') »^"^ OltCU tWO Or lureo 



after Riley. timcs as far, taken in connection 



with the gradual but slight enlargement of these organs towards the 

 tip. The sub- family comi)rises two well-marked groups, which are re- 

 garded by some entomologists as distinct sub-families, and which may 

 be designated by the terms of Chrysomelini and Eumolpini. In the 

 former the thorax is transversal, that is, wider than it is long, strongly 

 margined, and as wide at base as the elytra; the autenme are moder- 

 ately robust, sub-moniliform, and almost always less than half as long 

 as the body ; the anterior coxie are transverse; the 3d joint of the tarsi 



