26 DISEASES OF CROPS. 



Prevention. — (1) Deep-digging or ploughing, before 

 winter, is effectual in destroying the pupse of this moth. 

 (2) Raking over the ground after the pea crop has been 

 gathered brings the caterpillars to the surface. These are 

 sure to be cleared away by birds. (3) Rotations of crops. 



Cure. — (1) It has been stated that either quicklime, 

 sulphur, or soot placed along the rows of peas, after a 

 shower of rain, has proved eifectual in keeping off an 

 attack of this insect. (2) Syringing the plants (at the 

 end of May) with a mixture of paraffin oil and water de- 

 stroys the pest. 



The Pea Beetle {JBruchus pisi) belongs to the 

 same genus as the bean beetle (already mentioned), and 

 follows a similar life-history. The larva is white. 



The Pea Weevils (Sitona crinita and Sitona 

 Uneata). These small beetles (Fig. 8 A) devour the leaves 

 of pea and bean crops, by eating everything except the 

 woody midrib. Sitona Uneata (Fig. 8 B) is the largest 

 of the two species, is of a yellow colour, and has about ten 

 dotted stripes along the elytra. The legs and antennee 

 are of a red colour. Sitona cnnita is smaller than the 

 preceding species. It has grey elytra, spotted with black,- 

 and covered more or less with hairs. These beetles feed 

 during the day, and at night retire to rest in the ground. 

 They are very sensitive to sound, and if approached they 

 usually drop from the leaves to the ground. The Sitones 

 pair in May, and a little later the females deposit (?) num- 

 bers of white eggs.i 



Prevention. — Liberal manuring engenders a healthy 

 and vigorous growth. This may be a means of preventing 

 serious injury to the young pea-plants. 



' Little is known of the larval and pupal stages of these beetles. 



