139 



the farmer may know that a friend has come to his rescue, and that the Great Author 

 of Nature is saying to the littls pest, through the mouth of the minute and almost 

 microscopic insect which He has appointed to do His work, "Thus far shalt thou go, 

 but no farther, and here shall this grievous plague of flies be stayed." 



I may remark here that I have found a few Thrips haunting the leaf galls, which 

 have so abounded everywhere, in 1866, on the Clinton grai)e-vine, and which have 

 been named vitifolUv by Dr. Fitch. There can be but little doubt that they were prey- 

 ing here upon the minute bark-louse, which produces this leaf-gall. I have also noticed 

 them to be very abundant in the flowers of the Bracted Bind- weed ( Cahjstegia sepium). 

 As a small plant-feeding beetle (the Conotelus obscurus of Ericheon) also occurs in 

 great numbers in the same flowers, it is not improbable that the Thrips may feed 

 upon its larva}. 



In speaking of the natural enemies of the Phylloxera, Dr. Riley says 

 (Mo. Kept., Vr, pp. 50,51): 



The most efficient is a black species of Fringe-wing or Thrips, with white wings — 

 Thrips phylloxera of my MS. The egg, which is thrice as large as that of the louse, 

 ellipsoidal, and with a facetted surface, is deposited within the gall among its legiti- 

 mate inhabitants, and the young Thrips, which dilier from their parents not only in 

 lacking wings, but in being of a blood-red color, with only the extremities and the 

 members black, play havoc with the lice. They are active, supple creatures, and 

 turn up menacingly the posterior part of the body when distui'bed. They are found 

 in several diff'erent kinds of Phylloxera galls, and do more than any other species to 

 keep the leaf-inhabiting grape Phylloxera within bounds. 



Mr. Pergande, whose acquaintance with the Thripidae is very exten- 

 sive, writes in Psyche (III, p. 369) : 



That many species of the Thrips are vegetable feeders in some of their stages has 

 long been well known, and I have seen numerous species on all kinds and all parts of 

 plants, and some of these Thrips I have seen in the act of feeding, but I have also ob- 

 served that not all species have entirely the same habit, and that some in one stage or 

 another are carnivorous. Especially have I noted this to be the case with a species 

 which is frequently found upon the leaves of Platanns and upon other plants which 

 are badly infested with Tetrani/chits telariiis, upon the adults and young, and probably 

 also upon the eggs, of which these Thrips feed. It may also turn out that two or 

 three species which swarm in great numbers in the blossoms of clover, which are 

 usually full of the eggs and larvas of Cecidomyia Itguminicola, are particularly car- 

 nivorous, and further observations may prove that they mainly search and feed upon 

 the Cecidomyia, I may also mention here that this year, as late as November 14, after 

 several quite cold days, I found for the first time Heliothrips hcemorrhoidalis Bouch6 

 on apple leaves in the orchard of the United States Department of Agriculture, as 

 lively and active as in hot-houses, where this species was o<ily observed previously. 

 I may also mention the presence of Heliotlirips dracwme Heg. in the conservatory of the 

 Department of Agriculture, an insect which is reported as doing immense damage to 

 Draccenas in hot-houses in dift'erent parts of Europe. 



In 1886 Di. Karl Lindeman published results of his studies on the 

 Thrips in Eussia, and treats of five species as infesting various plants. 



Thrips secalina Lindeman, a new species infesting and subsisting upon 

 grain and Timothy grass. 



Phloeothrips frumentaria Bel., in ears of corn, the larvoe sucking its 

 food from the plant. 



Chirothrips aniennata Osborn, a species that was first discovered by 



