52 



Methods of control, — When this leaf -miner occurs in kitchen gardens 

 it is most easily controlled by gathering and destroying the leaves 

 as soon as found infested, and neighboring plants which serve it for 

 food should be treated in the same manner. In large fields of sugar 

 beet much injury might be averted by proceeding in the same manner 

 at the outset of attack. 



Insecticides have been suggested, but the habit of the maggot of 

 feeding within the leaf at once indicates their uselessness. Kerosene 

 emulsion has been tried without effect. Mr. Sirrine has observed that 

 many gardeners and farmers on Long Island, where this insect is a 

 spinach pest of importance, have practiced late fall and early spring 

 plowing, and are still troubled with it. But it is probable that clean 

 culture is not also practiced, hence the insects have an opportunity to 

 breed in weeds and return to cultivated plants. As the insect appears 

 to prefer spinach to beets, it is possible that the former might be used 

 as a trap crop in sugar-beet fields. 



PLANT-BUGS. 



The sugar beet furnishes sustenance for hordes of sucking insects, 

 such as plant-bugs, plant-lice, leaf-hoppers, root-lice, and numerous 

 related forms, but many of these insects live normally on wild plants, 

 weeds, and grasses, on which their younger stages are passed, and 

 prefer most other vegetable crops, when readily obtainable, to beets. 

 Among the more common forms of these insects which obtain nour- 

 ishment by suction are several species of true bugs of the family 

 Capsidas, generally termed plant-bugs, although some forms are also 

 known as leaf-bugs, chinch bugs, and by similar names indicative of 

 their habits or appearance. The commonest and most injurious of 

 these insects are two forms of false chinch bugs and the tarnished 

 plant-bug and garden flea-hopper. 



THE TARNISHED PLANT-BUG. 



( Lygus pratensis Linn. ) 



As this is the commonest of all bugs, and, according to general ver- 

 dict, one of the most troublesome, it may serve as an example of this 

 class. It is at home practically everj^where in North America, from 

 Canada to Mexico, and attacks most plants whether cultivated or wild. 

 It occurs in fields of sugar beet throughout the warm season, and fre- 

 quently does damage to garden crops, both vegetable and fruit, and to 

 trees grown in nurseries. 



The mature plant-bug is of the appearance shown in figure 51 at the 

 left. The general color is a pale, obscure, grayish brown, marked with 

 black and yellow, the thorax also with red. The pattern is variable, but 

 more or less as illustrated. The legs are still paler brown or yellow- 



