334 BOARD OF AGRICULTURE. 



the damage done this year was greater than ever before. This 

 evil seems wide spread in Essex County, as not in Swampscott 

 alone, but in Lynn, Salem, and parts of Danvers, the onion crop 

 has been similarly infested. About 1100,000 worth of onions 

 are raised in Essex County alone, and Mr. Ware judged that at 

 least a tenth part was destroyed by this new pest ; so that in one 

 county alone and by one kind of injurious insect we have in 

 one season lost $10,000. The onion crop is next to the hay crop 

 in value, as it is sold for cash. 



On examining the specimens brought into the Museum of the 

 Peabody Academy of Science, the leaves were found to be cov- 

 ered with hundreds of a minute Thrips, which by gnawing the 

 surface of the leaves, had caused them to turn white in spots, 

 and subsequently yellow ; where they were most numerous the 

 outer skin of the fleshy leaves was entirely eaten off, and though 

 it was difficult to imagine that so minute insects could have 

 caused the death of so stout and thick-leaved a plant, yet here 

 were hundreds of the culprits in all stages of growth plying 

 their jaws before our eyes in proof. 



This insect, which occurred in both sexes and in all stages of 

 growth from larva? of minute size, proved to be the wheat Thrips 

 of Fitch (^Limothrips tritici), who gives an account of its appear- 

 ance and habits in his " Second Report on the Noxious, etc , In- 

 sects of New York," p. 304. His attention # was first called to 

 this insect by a correspondent in Wisconsin, who found them in 

 great numbers in blossoms of various plants. He wrote Dr. 

 Fitch that they first "made their appearance about the middle of 

 June, or at least they were then first noticed, so far as I have 

 heard. For about two weeks they were found in the blossoms 

 of wheat and of clover, causing numbers of the blossoms to 

 wither, and in some cases the kernel was also attacked." Dr. 

 Fitch himself never seems to have noticed this insect in New 

 York, nor that it has ever been found in the onion, but thinks 

 it is the species to which Dr. Harris refers in his treatise. In 

 that work the author speaks of a " pernicious insect in the ears 

 of growing wheat," which " seems to agree with the accounts of 

 the Thrips cerealium which sometimes infests wheat, in Europe 

 to a great extent." From his brief description it is probably the 

 insect now under consideration to which Dr. Harris refers. 



Tbe various kinds of Thrips are minute, narrow-bodied insects 

 seldom exceeding a line in length, and remotely allied to the 



