128 INSECTS INJURIOUS TO VEGETABLES 



of different habits, and among these are the leaf-miners — small, 

 white maggots prodncing two-winged flies resembling the house 

 fly. These burrow between the two surfaces of the leaves and 

 form blotches termed mines. The principal species, the beet 

 or spinach leaf-miner (Pcgomya vidua Lint.), is illustrated 

 (fig. 8i). We have not as yet ascertained any perfectly satis- 

 factory remedy for the leaf-miners. 



PLANT-BUGS, LEAFHOPPERS AND APHIDES 



Hordes of sucking insects, many plant-bugs, leafhoppers 

 and numerous related forms are present in fields of sugar-beet 

 at all times, and sometimes accomplish very considerable in- 

 jury. Among the most prominent of these are the false chinch- 

 bugs. 



The most satisfactory manner of keeping false chinch-bugs 

 in check is by clean farming methods, destroying purslane and 

 other weeds, and the cleaning up of crop remnants before 

 winter, so as to leave no place for the insects to pass the 

 winter. Some growers have observed that the flooding of 

 fields infested by these insects forces them to leave, and the 

 growing of mustard as a trap crop gives good results, provided 

 the precaution is always taken to destroy the mustard before it 

 runs to seed. 



The sugar-beet leafhopper (Eutcttix tenclla Baker) came into 

 prominence as a beet pest in Utah, Idaho and Colorado in 1905, 

 doing damage that year estimated at $500,000. This insect has 

 become locally known as "white fly" and its injury as "blight." 

 It has been noticed that late-planted beets are principally 

 damaged and that early plants are less injured, and it may be 

 that on this or a similar point in its life economy may hinge 

 the remedy. It is worthy of remark that the species was un- 

 known to science until 1900. 



For the aphides which attack sugar-beet, it is sometimes un- 



