EEPOET OF THE ENTOMOLOGIST. 28u 



THE PEAE MIDGE OR PEAR DIPLOSIS. 



{I>iplosis nigra [f], Meigen.) 



Order Diptera ; Family Cecidomyid^. 



[Plato YII; Figs. 2, 3, and 4.] 



"We have for some time been interested in an insect which has ap- 

 peared in a limited region near Meriden, Conn., confined almost entirely 

 to the large fruit farm of Messrs. Coo Bros. In tbe spriug of 18S1 

 these geutlemeu had some slight correspondence with the Department, 

 of which no mention has been made in the rex)orts, and there the matter 

 was dropped untU June, 1884, when they wrote to us in reference to the 

 matter. 



As will be seen by what follows, there is every reason to believe that 

 this is an introduced species; that it has been introduced within quite 

 recent years, and that it is so far copfiued to a very limited region. It 

 is for these reasons that we call particular attention to it now, as we 

 did at the meeting of the Mississippi Valley Horticultural Society held 

 in i^ew Orleans last January, where we urged, as we would now urge, 

 that some decisive steps be taken to stamp it out. If, as we now believe, 

 this new pest js confined to the orchards of tlio Messrs. Coe and such 

 as immediately adjoin them, it seems to us that some such society as 

 the American Pomological Society would be justified in empowering a 

 committee to especially look into the matter and effectually destroy 

 the pear crop within the limits of the insect's present distribution in this 

 country for two or three consecutive years, compensating, if need be, 

 the owners for the loss of their crops. 



In view of the immense losses sustained within the last twenty-five 

 years by the spread of introduced injurious insects, which might in the 

 beg^inning have been stamped out or kept out by proper concert of ac- 

 tion, we cannot urge, too strongly such action in this case. 



In order to learn all possible facts in reference to the insect, we had 

 j\Ir. Smi;h visit the locality, instructing him to collect u large amount 

 of material, to ascertain whether the larva leaves the fruit for pupation 

 before the fruit falls or afterwards, and more particularly to collect all 

 lacts bearing upon its possible importation and upon its distribution. 

 Mr. Smith's report was published in our last annual report (pp. 30G-o9S) 

 and need not be repeated here. 



LIFE HISTORY AND nABITS. 



From a careful rearing and study of this insect in the office, and from 

 corrcsi)ondence with the Messrs. Coe, as well as from ]\Ir. Smith's report, 

 we may suiumarize the iiisecL'.s history in America as i'uliows: 



The eggs are laid in the spriug, in the iiowereud of the fruit, as soon 

 as or even before it " sets." The fruit grows and soon assumes a some- 

 what distorted appearance, or, as Mr. Smith says, "an in-egular, some- 

 what knobby" look, or occasionally seeming abnormally round. If one 

 of these young pears be cut open, its interior will be found to be chan- 

 neled and grooved, the seeds separated and eaten into, and the entire 

 core disorganized. Surrounded with excremental j)e]lets and partly im- 

 bedded in the flesh of the i'ruit will be found from ten to thirty little 

 yellowish-wldtc maggots, which, as they grow, absorb more and more of 



