13 
plant, Cleome-mtegrifolia. Tlio injury is done, as with all the flea- 
heetles, by eating little holes through the leaves, until the latter turn 
brown and crisp. 
The remedies are the same as for the preceding species. 
ONION THRIPS. 
{TJirips striatus Osb. ?). 
Several inquiries have come to this office concerning a minute 
fly that is ruining the onion crop, by causing the tops to turn white 
and die in July and August. The same insect has been noticed by 
us doing serious harm to onions in this vicinity and in other locali¬ 
ties in the State during the past two summers. 
The Thripidse are very small insects, the largest measuring only 
about one-eighth of an inch in length. The mouth parts are rudi¬ 
mentary, and do not seem to be well fitted either for biting or 
piercing and sucking the juices of plants. Some forms are carniv- 
Fig. 11. 
erous, but most that have been studied are vegetable feeding. In 
form they are long and slender ; the wings, when present, are four 
in number, very narrow, and more or less ciliated with long, slender 
marginal hairs. In many there are also numerous stout hairs or 
spines on the surface and borders of the fore wings. The mature 
insects are usually very active, and when disturbed run about, 
throwing up the tip of the abdomen as if to sting, but they have 
no power to inflict such injury, and we have found by watching 
them under a glass that the abdomen is thrown up for the purpose 
of assisting in spreading the wings. Those studied seemed to have 
no power to spread the wings in any other way. After the wings 
