368 



Kansas State Board of Agriculture. 



Habits and Life History. 



"There is certainly but one generation annually, though this appears 

 to be long-drawn-out, and scattering individual larvae and pupae may be 

 found throughout every month of the year. (Fig. 311.) As a rule, 

 however, the insects pass the winter in the adult 

 stage within the roots where they develop. Dur- 

 ing May they abandon the old roots and seek out 

 fresh plants or fields in which to lay their eggs. 

 The female gouges out a shallow cavity, more 

 often in the crown of the plant (Fig. 312), some- 

 times at the sides of the root, even two or three 

 inches below the crown, and in this places singly, 

 but not far apart, about half a dozen pale, whitish, 

 elliptical, very minute eggs. These hatch in about 

 a week, and the larvae, for a time, feed in the 

 excavation made by the mother, but soon burrow 

 downward into the root, and before the first of 

 August the majority. of them have become fully 

 grown and passed into the pupal stage. By Oc- 

 tober nearly all have become fully developed 

 beetles, but make no attempt to leave the plant 

 until the following spring." 1 



Usually the insect does not attack alfalfa and 

 clover the first year on account of the roots being 

 too small to furnish sufficient accommodations. 

 Infested plants will die sooner or later, the time 

 depending upon the weather conditions. The 

 presence of the insect is indicated by the alfalfa 

 dying out in patches. If the season is dry these 

 spots will appear shortly after the first cutting, 

 but if there is plenty of rain or good growing con- 

 ditions these patches will not appear until late 

 fall, or maybe not until spring. 



Methods of Control. 



The only reliable measure to be suggested is 

 to plow up the field as soon as the first crop is 



removed. This plowing must not be delayed, for the larvae will then 

 have passed into the pupal stage, and plowing would not injure them to 

 any extent. 



CLOVER-ROOT CURCULIO. 



(Sitones hispidultis Fab.) 



The adult, black, hard-bodied beetle, about one-eighth of an inch long. 

 Found eating irregular patches from the margin of the leaf. (Fig. 

 313.) The larva, a white, footless baggot-like grub, with a light 

 chocolate-brown head, when full grown about one-fourth of an inch 

 long. Found eating cavities along the main roots. (Fig. 314.) 



FIG. 312. Clover root 

 showing work of the 

 clover-root borer ; slightly 

 enlarged. (After Webster, 

 U. S. Dept. Agr.) 



1. Cir. 67, Div. Ent., U. S. Dept. Agr. 



