BULLETIN 192. 



INSECTS INJURIOUS TO THE VINE. 



133 



swarms, as they sometimes occur. The jarring method as described for 

 the root beetle will also prove valuable. 



Since these insects feed in the larval state upon the roots of grasses 

 growing along the roadsides or fences or irrigation ditches, much can be 

 done to prevent an outbreak by keeping euch places free from vegetation. 



WIRE WORMS. 



These are long cylindrical worms with a dark 

 brown leathery covering resembling somewhat a 

 piece of rusty wire. They live for a year or 

 more in the ground, feeding upon the roots of 

 plants. They feed upon a variety of plants and 

 are not restricted to grape roots alone. We 

 have taken as many as fourteen of these worms 

 from around the roots of a vine from 

 a foot and a foot and a half from the 

 surface. During the growing season of 

 the vine when the vineyard is free 

 from vegetation these wire worms must 

 feed to a considerable extent upon the 

 roots of the vine. The adult is the well- 

 known click or snapping beetle, the one 

 most commonly met with being about 

 one-half an inch long, slender, and of 

 a dark brown or black color. We have 

 seen immense swarms of these click 

 beetles in a vineyard near Hanford, 

 and when they occur in such large 

 .numbers they probably do considerable injury 

 to the vine as root feeders. 



When young vines are planted in soil which 

 has previously been in hay or pasture the wire 

 worms may attack the bark just below the sur- 

 face and kill the vine by girdling it. Rupestris 

 St. George seems particularly susceptible to this 

 form of attack. The vines may be saved if the 

 wire worms congregated around the collar of the 

 vine one or two inches below the surface are 

 collected by hand in time. 



Treatment. We know of no generally satisfac- 

 tory remedy for these insects. Turning up the 

 soil is recommended for the same insect in the 



FIG. 22. Young vine gir- 

 dled by wire worms. 



