12 MASSACHUSETTS HORTICULTURAL SOCIETY. 



merly the State Entomologist of Xew York, was probably the 

 first entomologist in America or elsewhere to take this question 

 into serious consideration. In 1854, following a disastrous attack 

 upon the wheat crop of the eastern United States by the wheat 

 midge {Diplosis tritici), a species accidentally introduced from 

 Europe during the early part of that century, Doctor Fitch made 

 a careful study of the insect both in this country and from the 

 European records, and was impressed with the fact that in Europe 

 the insect in ordinary seasons did no damage, and that when 

 occasionally it became so multiplied as to attract notice it was a 

 transitory evil which subsided soon. He compared the insects 

 taken from wheat in flower in France with those taken from wheat 

 in flower in New York, and he found that in France the wheat 

 midge consisted of but seven per cent of the insects thus taken 

 while its parasites consisted of eighty-five per cent; whereas in 

 New York the wheat midge formed fifty-nine per cent of the 

 insects captured and there were no" parasites of which he could 

 be certain. He then came to the conclusion that it was a question 

 of introducing the parasites into the United States, and he made 

 an effort by correspondence with English entomologists, which 

 however was a failure owing to the fact that he was unable to 

 enlist the active cooperation of his correspondents. 



Later William LeBaron, State Entomologist of Illinois, at- 

 tempted to transport a parasite of the oyster-shell bark-louse of the 

 apple from one part of the State of Illinois to another part of the 

 same State where the parasites seemed to be lacking. Some slight 

 success was reported, but the parasite subsequently proved to be 

 one of general American distribution. 



Another international attempt was made in 1873, when Planchon 

 and Riley introduced an American predatory mite into France. 

 The mite was an enemy of the grapevine Phylloxera, and became 

 established in France, but produced no appreciable results in the 

 way of checking the pest. In 1874 efforts were made to send cer- 

 tain parasites of plant-lice from England to New Zealand, but with- 

 out recorded results of value. In 1880, in an article in the Annual 

 Report of the Department of Agriculture for that year, the speaker 

 shoAA'ed that the transportation of scale-insect parasites is especially 

 easy and especially desirable. In 1883 Prof. C. V. Riley imported a. 



