DIPLOSIS PYRIVORA, THE PEAR-GNAT. 127 



answered at once, ' The fallen pears are attacked by one of the 

 gall-gnats Cecidomyia nigra, Mg., restricted genus uncertain.' 

 How many years I had noticed it before this I do not know. I 

 do not remember having observed the pest on any other pear 

 until last year, but as my attention was then especially directed 

 to this point I found other pears were also affected, but not to 

 the same extent by any means. I may say, however, that the 

 affected pears are much more conspicuous on the Marie Louise 

 than on the other kinds. I am told that the pest occurs in the 

 adjoining parish of Fairlight." " The Marie Louise is a Belgian 

 pear, but has been general in this country for at least fifty years." 

 Although these data do not prove that the pest has been imported 

 into England from France or Belgium, yet the facts that these 

 foreign pears have been the ones first and chiefly affected, and 

 that the insect was apparently unknown in England before the 

 last few years, make a prima facie case in support of this 

 opinion. 



Though the pears in England and America seem to have been 

 blighted in exactly a similar manner, and, in consequence of 

 Dr. Riley's suspicions that the insect had been imported from 

 Europe, it was almost certain that it must be specifically the 

 same in both countries ; yet entomologists felt anxious to prove 

 this by breeding the fly here, from the larvae in pears, in the 

 same way as Dr. Riley had done in America ; and I am happy 

 to say that Mr. Bloomfield has enabled us to succeed. He 

 forwarded some of the affected Marie Louise pears to Mr. 

 Inchbald (so well known for his researches on the Cecidomyiidae, 

 and skill in rearing them from the larvae) in June, 188(3, but as 

 that naturalist has recorded in the ' Entomologist ' for February, 

 1887, he did not then succeed in rearing any imagines from the 

 larvae. In June, 1887, Mr. Bloomfield again sent some more 

 pears (full of larvae) to Mr. Inchbald, as well as to Miss Ormerod, 

 Mr. Fitch, and myself, and both Mr. Inchbald and I have had 

 the satisfaction of rearing both males and females of the Diplosis, 

 which I have no doubt is identical with the D. pyrivoi'a of Riley. 

 Mr. Inchbald has bred the gnats in great numbers, and has been 

 enabled to supply many of his friends with specimens. With 

 both Mr. Inchbald and mysehf the females have been more 

 numerous than the males, in proportion of about two to one. In 

 America Dr. Riley found that the imagines began to emerge from 



