144 



Forty-fifth Report on the State Muse mi. 



Fig. 7 — Section of a pear con- 

 taining the larvae, and an un- 

 infested one for comparison 

 of forms (original). 



Discovered at Catskill, N. Y. 

 During the last week in May of the present year (1891), some young 

 pears were sent to me from Catskill, N. Y., with 

 the inquiry of the name of the attacking insect. 

 The nature of the inquiry was not evident at 

 the first inspection, as the fruit was fair, 

 unbroken, and showed no external injury — its 

 peculiar deformation being unnoticed. But 

 upon cutting into one the interior was found to 

 be occupied by a large company of active 

 little bodies which, wriggling out and dropping 

 to the table, commenced to give evidence of 

 their sharing in the saltatory powers belonging 

 to many of the Cecidomyids and particularly 

 to the genus Diplosis, by throwing them- 

 selves from a small box in which some had 

 been placed to a distance of two inches and 

 more in a single bound. The attack upon 

 the fruit was at once recognized as that of the 

 pear midge, Diplosis pyrivora. 

 In a visit to Catskill immediately following this discovery, all the 

 orchards that could be examined during the day, within a radius of 

 two miles, were found badly infested with the insect, and its presence in 

 other orchards more distant was reported. In those of Mr. Theodore A. 

 Cole, where it was first detected, the attack was the most severe. 

 There were here many old and quite large Lawrence pear-trees, heavily 

 laden with fruit, but an examination showed that at the least ninety 

 per cent of the fruit was filled with the full-grown midge larvae. Other 

 varieties were infested in a less degree, among which were the Vicar, 

 Anjou, Seckel, Bartlett, and Buerre Bosc. Mr. Cole had observed the 

 attack in his orchards four years previous (in 1887); in 1889 the 

 Lawrences were almost entirely destroyed by it. lie had neglected 

 calling attention to it until the present season, thinking that it was a 

 well-known trouble which could not be prevented. 



In passing over the orchards and observing so large a proportion of 

 the fruit infested, Mr. Cole asked — " how can this condition follow a 

 year (1890) in which I had no pears: where did the midge breed?" 

 This could not be answered until, upon coming to some Buerre Hose 

 trees which were now for the first time found to contain the larvae, 

 Mr. Cole recalled the fact that this variety had borne some fruit the 

 preceding year and was the only one that had done so. How the 

 midge had been carried over "a no pear year" was at once satisfac- 



