THE KOUGH-HEADED COEN STALK-BEETLE 



LARVA 



DESCRIPTION 



The full-grown larva of Euetheola rugiceps (fig. 2.) is a robust, 

 thick-bodied grub, with an approximate length oi 32 millimeters 

 (1£ inches) and an average thickness of about 6 millimeters. It is 

 nearly pure white, deepening posteriorly to a dark gray or brownish 

 tint, due to the dark color of the vis- 

 cera appearing through the trans- 

 parent cuticle; the legs are yellowish 

 amber; the spiracles orange; the head 

 shield a distinctly reddish hue, closely 

 approximating a bright shade of In- 

 dian red. In alcoholic specimens these 

 colors are invariably much obscured. 

 The most distinctive morphological 

 features of the larvae are found in the 

 head shield and the last ventral seg- 

 ment. The head shield (PI. Ill, A) 

 is distinctly, even coarsely punctate,, pig. 2.— Fuii-grown larva of Euetiw- 

 the punctures being especially coarse SSJ^Sax^j^tS^ 7 ^ w e r. 

 and dense on the portion immediately Walton) 

 above the clypeus. 



The last ventral segment of the larva (PL III, D) bears a some- 

 what irregular, median, double row of modified bristles, each having 

 the appearance of a denticle or minute spine. In the possession of 

 this feature the larva of Euetheola rugiceps is unique, so far as the 

 writers are aware, among the Dynastini and agrees with the larvae 

 of the genera Phyllophaga and Anomala, though in these the corre- 

 sponding character is much more regular and 

 clearly defined than in Euetheola (PL III, 

 D-G). In all other respects it resembles the 

 type of larva normal to the Dynastini. 



METHODS OF COLLECTING AND REARING 



Owing to the pugnacious habits of the larvae 

 it is best to place each in a separate receptacle 

 when collecting, also to place a little vegetable 

 mold or fine soil in the box to prevent the larva 

 from rolling about and being injured. 



Attempts were made to rear the larvae in 

 flowerpot cages, similar to those used to confine 

 the beetles, but the results were disappointing. 

 The failures were perhaps due, in part, to the fact that suitable food 

 was not supplied the young larvae when the cages were started, as 

 the food requirements of the young larvae were then very imperfectly 

 known; possibly, also, to inability to protect the larvae against cer- 

 tain of their enemies. Ants frequently invaded the cages, and, as 

 they are known to attack and kill the larvae, were doubtless respon- 

 ible in some measure for the unsatisfactory results obtained. The 



04051°— 24 2 



Fig. 3. — Young larva of 

 Euetheola rugiceps 

 immediately a f t e r 

 hatching-. Note rela- 

 tive size of head and 

 trunk, in comparison 

 with FiK- -■ (Drawn 

 by W. It. Walton) 



