INSECTS INJURIOUS TO CLOVER 



201 



burrowing and feeding in the roots, and during late May and early 



June the females deposit their eggs along 



the sides of the tunnels. " The female 



gouges out a shallow cavity, more often 



in the crown of the plant, sometimes at 



the sides of the root even 2 or 3 inches 



below the crown, and in this places, 



singly, but not far separated, about a 



half dozen pale whitish, elliptical, very 



minute eggs. These hatch in about a 



week, and the larva? for a time feed in 



the excavation made by the mother, 



but soon burrow downward into the root, 



and before the ^st of August, the majority 



of them have become full-grown, and 



passed into the pupal stage. By October 



nearly all have become fully developed 



beetles, but they make no attempt to 



leave the plant until the folio wing spring." 



The spread of the insect occurs very 



largely in the spring when the beetles 



fly from field to field, seeking uninfested 



plants in which to perpetuate their kind. 



It has been observed that alsike clover 

 is not so badly injured as the mammoth 

 and common red clover, on account of 

 the fibrous roots and the tendency of 

 its tap-root to divide. In Europe alfalfa 

 is injured, but no injury has yet been 

 reported to that crop in this country, 

 though it may be anticipated. 



" While an infested clover plant sooner or later succumbs to 

 an attack by this insect, life may be lengthened or shortened by 

 meteorological conditions. Thus, if the spring or early summer 

 is very dry, the plants begin to dry in patches late in June, as 

 soon as the hay crop is .removed; but if there is much rain dur- 



FIG. 145. Clover root, 

 showing work of clover 

 root - borer. Slightly 

 enlarged. (After 

 Webster, U. S. D. Agr.) 



