Order THYSANOPTERA. 



The insects of this order are commonly known as "Thrips," and often cause 

 severe injury to growing plants. They are of very small size, very slender, 

 somewhat fusiform, with very delicate slender fringed wings which are laid flat 

 upon the back when at rest and are not even visible to the ordinary observer 

 without a lens. 



The mouth parts are made up of a number of slender lancets, only the points 

 of which protrude beyond the mouth opening. With these they scrape the 

 surface of the leaf or plant and exhaust the cell beneath, leaving a yellow spot. 

 Onions are frequently turned almost white when badly infested, and cabbage 

 may be completely devitalized. " Silver-top " on grasses is one of the effects, 

 and for several years past injury has been caused on nursery peaches in some 

 parts of the State ; growth being checked and the tree dwarfed or crippled. 



Not all species are harmful, however, some occurring in flowers and others in 

 such situations as to make it reasonably certain that they are predatory. Yet, 

 as a whole, this little order must be considered as injurious. 



As to remedial measures, it is difficult to make recommendations save the 

 impossible one of getting abundant and seasonable rains. The insects thrive 

 best in a dry time and may be completely checked in their full-tide by a heavy 

 rain, especially if at all cold. Any contact poison will kill them, even if con- 

 siderably diluted, and quantity of mixture rather than strength is important. 

 Cold water alone will be quite effective if plenty of it is at hand. 



Practically no collecting has been done in New Jersey in this order, though 

 the insects merit much more attention than they have received, from their 

 economic importance as well as from their interesting structures. 



The present list I owe to the kindness of Mr. Theodore Pergande, of the U. S. 

 Department of Agriculture, and it is based entirely upon his knowledge of the 

 general distribution. All the notes are by Mr. Pergande except that charging 

 T. tritici with injuring nursery peaches and those that are especially marked 

 (Sm). 



Family THRIPIDJE. 



COLEOTHRIPS Halid. 

 C. trifasciata Fitch. Infests grain and grasses. 



CHIROTHRIPS Halid. 

 C. antennatus Osb. Infests grasses. 



LIMOTHRIPS Halid. 

 L. cerealium Halid. Infests grain and grasses. 



(77) 



