198 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



stimulates a quick growth which enables the plants better to 

 withstand the weevil injury. The use of a brush drag with which 

 a spike-tooth harrow is combined has been found an excellent 

 means of killing the larvae, as they are knocked to the ground 

 and large numbers killed by the fine dust. If the field is very 

 hard it is advisable to disk it before using the drag. After the 

 use of the drag, the fields should be watered where there is 

 irrigation. In summarizing the methods of control, Professor 

 Titus recommends: "That alfalfa be disked in early spring to 



stimulate it to better growth. 

 That the first growth be cut 

 when the most of the eggs 

 have been laid (middle of 

 May) and then brush-drag 

 the field thoroughly. Fields 

 should be brush-dragged 

 again after the first crop has 

 has been cut. All weeds 

 and rubbish should be clean- 

 ed from the fields, yards, 

 ditches and fence rows so 

 that there will be less op- 

 portunity for the weevils to 

 find winter shelter. Alfalfa 

 should not be allowed to 

 grow more than seven or 

 (Bryobia eight years in infested 



districts." 



Quarantine measures to prevent the spread are matters of 

 local and state jurisdiction but are of the highest importance 

 to the alfalfa growers of the country. 



The Clover-mite * 



The Clover-mite is nearly related to the common red spider 

 of greenhouses, with which it is often confused, belonging to the 

 same family of vegetable-feeding mites. It is, however, about 

 twice the size of the red spider, being four one-hundredths inch 



* Bryobia pratensis Garman. Family Tetranychidce. See C. L. Marlatt, 

 Circular 19, 2d Ser., Division of Entomology, U. S. Dept. Agr, 



Fia. 166. The Clover-mite 

 pratensis). 



