AiiT. 2 BEETLE LARVAE OF GALERUCINAE BOVING 27 



chitinous parts pale yellow, setal cups not particularly darker than 

 the sclerites, legs shining, generally blackish brown to black. 



Setae (fig. 41) rather short, varying from about one-eighth of the 

 length of a normal body segment to about one-quarter of its length; 

 some setae capitate, others pointed ; some pale, others dark. Setal 

 cups rather inconspicuous. 



The shape of the head capsule, of labrum, mandible, and other 

 mouth parts (figs. 39, G8), the development of the thoracic and 

 pygidial shields and of the sclerites, the arrangement and form of the 

 Fetae completely agreeing with the corresponding parts in the larvae 

 of Galerucella notata and Galerucella cr'ibrata^ except in unim- 

 portant minor variations in the number of the setae on some of the 

 sclerites. 



Taxonomic coirwrtents. — The propriety of establishing the genus 

 Monoxia as distinct from the genus Galerucella is not substantiated 

 by the features observed in the larva of the type species Monoxia 

 puructicollis^ as this larva is distinguished from the larvae of Galerur 

 cella notata and ci^hrata by the mere specific characters of having 

 relatively smaller setae and dark-colored skin. Moreover, in respect 

 to the latter character it should be remembered, as mentioned on page 

 24, that some specimens of the larvae of Galerucella cribrata^ pre- 

 served in the United States National Museum, possess a coloration 

 of the skin varying from slightly more grayish than in the normal 

 creamy yellow larva to dark olive green as in Monoxia 'puncticollis. 



T]ie larva of the species Monoxia con^puta, however, is entirely 

 different from this larva of Monoxia puncticollis, positively can not 

 be placed in the same genus with it, and a new genus will probably 

 have to be created for it. Further discussion on the taxonomic posi- 

 tion of Monoxia consputa will be found where the species is treated 

 on page 29. 



Habits. — The larva of Monoxia puncticollis is injurious to sugar 

 beets, skeletonizing or eating through the leaves and often completely 

 devouring young plants of considerable size. Other food plants 

 are Ghenopodiu/in album, Dondia erecta, and Salsola pestlfer. It 

 pupates in a simple excavated cell in the ground, in this regard dif- 

 fering from Galerucella notata and G. cribrata, which form a reticu- 

 late cocoon above the ground. 



Literature. — 



Chittendkn, F. H., and Mabsh, H. O. 



1920. U. S. Dept. of Agr. Bui. 892 (The Beet Leaf Beetle). Professional 

 paper from Bureau of Entomology. (Eggs attached in clusters to leaves 

 of food plants; young larva with dark brown thoracic shield, gray skin 

 and rather dark sclerites, hail's comparatively longer than in mature 

 larva. List of literature.) 



