176 



INSECTS INJURIOUS TO STAPLE CROPS. 



thereby preventing their developing and migrating to other 

 fields." A more frequent and thorough rotation of the 

 crop will thus be of value. 



Meadow-maggots. (See page 90.) 



INJURING THE STEM. 



The Clover Stem-borer [Laugmna mozardi Fab.). 



Early in June one frequently finds the beetles of the 

 Clover Stem-borer here and there in the clover-field. 

 They are slender, shining beetles, about one- third of an 

 inch long, with red head and thorax and bluish-black 



Fig. 97. — Clover Stem-borer {Languria moz((rdi). Shows the eggs 

 natural size and magnified, the beetle, larva, and pupa much 

 enlarged, and above, a clover-stem with the larva at work in 

 it. (After Comstock.) 



wing-covers. The beetles themselves seem to do little or 

 no harm. Hibernating over winter, they lay the eggs in 

 the pith of the stems early in June, and the larvae emerg- 

 ing from these feed upon the pith of the stem, often ver}- 

 seriously weakening or killing it. The larvae become full- 

 grown in a short time, transform to pupge, and the beetles 

 appear by August. 



Clover is only one of a dozen food-plants of this insect, 

 which is widely distributed. It rarely does any consider- 



