The metamorphosis also is interesting. The larva resembles 

 the adult in form, and has similar mouth parts and food habits. 

 The pupa, however, takes no nourishment, and is enclosed in a 

 transparent skin, which is finally moulted as the insect reaches the 

 adult form. The pupffi of some species possess a slight power of 

 motion, their movements being very sluggish and uncertain ; others 

 are entirely motionless, and appear to have a nearly complete 

 metamorphosis. 



The members of this order live in flowers, upon the leaves or 

 under the bark of plants and trees and in turf or fungi. In Aus- 

 tralia they are said to form galls upon the leaves of trees, and in 

 our own country they have been frequently reported as inhabiting 

 galls formed by other insects. Several species have long been con- 

 sidered injurious to cultivated plants, especially to cereals. Ex- 

 tensive damage to grass also has been reported from all of the New 

 England States, New York, southern Canada, Ohio, northern Illi- 

 nois and Iowa. Without doubt the insect causing this damage in- 

 fests a much larger territory than this, for it is so small that it 

 easily escapes observation, and the damage really done by it is 

 often attributed to other agencies. In order to become familiar 

 with its life history, studies were made upon it at the entomolog- 

 ical laboratory of the Massachusetts Agricultural College, under the 

 supervision of Prof. C. H. Feruald, to whom I am much indebted 

 for his able direction and kind encouragement in carrying on this 

 work, the results of which are here given. 



History. 



In 1875, Prof. J. H. Comstock, in his "Syllabus of a Course 

 of Lectures," mentioned a species of thrips which was doing very 

 great damage to timothy and June grass by working in the upper 

 joints. To this insect, of which he had seen only the larvae at 

 that time, he gave the name Limothrijys poaphagus ; but he pub- 

 lished no description of it previous to the appearance of his " In- 

 troduction to Entomology," in 1888. 



Five years before this latter date, Prof. Herbert Osborn pub- 

 lished, in the "Canadian Entomologist," Vol. XV., page 155, the 

 description of a species of thrips, under the name of Thrips stri- 

 ata. The description was made from a single specimen, and the 

 food plant was unknown to Professor Osborn ; but the published 

 description agreed so closely with the " grass thrips" that the two 

 were suspected to be identical. Not knowing whether Limothrips 

 2Joaphagus Comst. and Thrijis striata Osb. were positively synon- 

 ymous, I sent some of my specimens to the Division of Ento- 

 mology at Washington for determination, where they were referred 



