ORDER THTSANOPTERA. 73 



OEDER VII. THYSANOPTEKA.* 



Eepresented by the little group of which Thrips is the 

 type, and placed by some among the Hemiptera, to which 

 they seem closely allied, it may be said that though 

 the head ends in a short beak, yet these insects 

 differ from the bugs in having maxillae bearing 

 2-3-jointed palpi, while the labial palpi are present, 

 and, though very short, are composed of from two 

 to three joints. The order derives its name from 

 the long delicate fringe on its long, narrow, and 

 often veinless wings. In some species the wings 

 are wanting, at least in the males. The abdomen, 

 in certain species, ends in the males by a slender 

 joint, and in the females by a 4-valved borer. striatus. 



The eggs are somewhat like those of Hemiptera, being 

 cylindric, round at one end and crowned with a knob at the 

 other. The larva and pupa are both active, and in the 

 rather sluggish pupa the antennae are turned back on the 

 head, while the limbs and wings are enclosed in a thin 

 filmy membrane; the feet end in bulbous enlargements, 

 hence the name "bladder-footed" (Physapoda) applied to 

 the group by Burmeister. 



The wheat Thrips, Limotlirips cerealium Haliday, is in- 

 jurious to wheat; Thrips striatus Osborn (Fig. 58) destroys 

 onion-plants. These insects injure plants by puncturing 

 and killing the leaves; all the species are minute, and little 

 is known of them in the United States. 



Family Thripidae. Characters of the order as given above. 



* SELECTED WORKS. 



Haliday, A. H. An epitome of the British genera in the order Thy- 



sanoptera (Entomological Mag., iii. 439. 1836). 

 Packard, A. S. (Standard Natural History, second edit., 1888; also 



contains a list of described X. A. species by Th. Pergaude.) 

 Reuter, 0. M. Thysanoptera Fenuica. (1880.) 

 Uljanin, W. H. Embryology of Physapoda (Moscow. In Russian). 



