20 



FARMEES BULLETIN 856. 



the time the egg is laid until the adult or winged form appears. This 

 species is injurious to cabbages, turnips, potatoes, and cucumbers, and 

 injury generally is done by the adults piercing and sucking the 



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Fig. 14. — The onion thrips (TJirips tahaci) : Adult. Highly magnified. 



juices from the plants and later attacking fruits and shoots. It is 

 the cause of " buttoning," and is credited with carrying some forms 

 of blight on plants. Were it not that this insect feeds on so great a 



variety of plants, thus distributing 

 its attack, it would be a serious 

 pest indeed. 



Control. — This plant-bug, when 

 it occurs in great numbers, can not 

 be kept within bounds by any single 

 remedy. The great activity of the 

 pest makes it particularly difficult 

 to control. The best remedies are 

 nicotine sulphate, kerosene-soap 

 emulsion, and fish-oil soap. As 

 in the case of plant-lice, insecticides must be applied in the morning 

 before the insects have become thoroughly active and while dew is 

 on the plants. In the small garden, sweeping all the plants, grasses, 

 and weeds with an insect-collecting net will accomplish much toward 

 keeping the pest in subjection. 



Fuj. 15. — The tarnished plant-liug (Liious 

 pratcnmti) : Adult bug at left ; last 

 stage of nymph at right. Nearly four 

 times natural size. 



