Injurious LiscctSs 207 



is not very fur from the truth) that the whole business 

 of crop raising has come to consist mainly in a contest 

 against insect depredators. These are not discouraged 

 when they find a healthy and vigorous plant growth 

 wailing for them to feed on. Sometimes, indeed, they 

 will sweep o.T every plant in an early stage of growth ; 

 or they may delny their coming till just before harvest 

 and then consume the entire crop. 



The Wavy-striped Flea-beetle (Haltica Striolata) is 

 ver\' destructive to young Cabbages and Turnips. As 

 soon as the young cabbages appear above the ground it 

 attacks them by eating off the seed leaves ; later, when 

 the second leaves appear, the danger lies in another 

 quarter, and it will often be noticed that the plant wilts 

 and changes color. The grub has eaten away the roots. 



The same insects that attack young Cabbage plants, 

 and the Turnips, also infest the Radish. In some local- 

 ities it is almost impossible to grow radishes of a size 

 fit for the table before they are practicilly destroyed by 

 a small maggot. This maggot appears to be the larva 

 of a fly, closely related to those so destructive to the 

 Onion. 



The Imported Onion Fly lays her eg^s on the leaves 

 of the young and small onioti plants, near the ground. 

 They soon hatch,_and the maggots at once attack the 

 bulb. In about two w^eeks after this a second brood 

 of tiies appears, to be followed by more maggots. The 

 remedy consists in removing every infested bulb. These 

 may be known by the leave3 turning yellow. They can- 

 not be pulled up by the tops without risk of letting the 

 maggot escape from the decayed bulb. They must be 



