THE STRIPED CUCUMBER BEETLE 



237 



The Diamond-back Moth (Plutella maculipennis Curtis). 

 This is the insect whose caterpillar riddles cabbage leaves with 

 small holes. It is found upon the plants along with the green cab- 

 bage worm. The moth which lays eggs producing these cater- 

 pillars is yellowish above, and its wings, which are kept folded, 

 are turned up slightly at the tips. The wings also bear a long 

 fringe. The lower part of the folded wings is bronze brown. The 

 caterpillar is one-third of an inch long and pale green hi color. 

 It tapers toward each end, and is quite active. These caterpillars 

 pupate in small cocoons of delicate silk lace-work, and the brown- 

 ish pupa may be seen through the thin walls of the cocoon (Fig. 

 239). In winter-time the cocoons are to be seen on old cabbage 

 stalks in the field or on stored cabbages. 



Control. The remedies advised for the green cabbage worm 

 also control this pest. 



INSECTS ATTACKING CUCUMBERS, MELONS AND RELATED PLANTS 



The Striped Cucumber Beetle. This insect is destructive in 

 both the larval and adult stages. The beetle (Diabrotica vittata 

 Fab.) is slightly less than one-half of an inch hi length, and is 



FIG. 246. The striped cucumber beetle. (U. S. Bu. Ent.) 



black with yellow stripes (Fig. 246). It lays its yellowish eggs in 

 clusters upon the root of the plant, and the grub feeds on the root 

 within the ground. The pupal period is passed in the soil, and the 

 adults winter in rubbish and waste in the fields. Frequently one 

 finds small mites upon these beetles, but evidently the mites use 

 the beetles as a means of transportation, and it is doubtful whether 

 they appreciably reduce their numbers. 



