FLEA-BEETLES 327 



where they eat out a mine of the hloteh type, often being 

 numerous enough to kill the plant. The full-grown larva is 

 about i inch in length, orange, with the head, pronotum and 

 anal segment dark brown. The other segments are marked 

 with numerous brown spots. When mature, the larva descends 

 to the ground, where in an earthen cell, it transforms to a 

 white or yellowish pupa. In May and June in Missouri the 

 life cycle from egg to adult requires about three weeks. This 

 species has not been recorded as causing any very serious in- 

 jury. This may be explained in part from its being frequently 

 mistaken for the strii)ed cabbage flea-beetle. 



Reference 

 Riley, U. S. Eiit. Rept. for 1881, pp. 304-308. 



The Western Cabbage PYea-Beetle 



Phyllotrela pusilla Horn 



Along the eastern slope of the Rocky Mountains from Dakota 

 to Mexico and in New Mexico and southern California, the 

 wavy-striped flea-beetle is replaced 

 by this pitchy black, slightly bronzy 

 beetle from tV to iV inch in length 

 (Fig. 206). It has been recorded 

 as injurious to cabbage, radish, 

 turnip, horse-radish, mustard, rape, 

 pea, sugar-beet and corn. It also 

 feeds on hedge mustard and the 

 bee plant. The beetles hi})ernate 



Fig. 206. — The western cab- 

 l)ase flea-beetle (X IG). 



and are most destructive to the 



young plants soon after coming 



out of hibernation. The early stages have not been 



described. 



