Insects, etc., Injurious to the Pear. 343 



REFERENCES. 



(1) Onnerod, E. A. ' Handbook of Orchard and Bush Fruits,' p. 140 (1898). 



(2) Theobald, F. V. Journal of the S. E. Agricultural College, Xo. 11, 



pp. 27-31 (1902). 



(3) Cameron, P. ' British Phytophagous Hymenoptera,' vol. III., p. 97 (1889). 



(4) Westtvood, J. 0. Gardeners' Chronicle, p. 36, Jan. 18 (1851). 



(5) Kollar, V. ' A Treatise on Insects Injurious to Gardeners, Foresters and 



Fanners ' (Eng. Trans.), p. 271 (1840). 



THE PEAR MIDGE. 

 (Diplosis pyrivoTa. Riley.) 



This is a very serious enemy of pear growers, and one, unfortunately, 

 which seems to be steadily on the increase. In some districts it is 

 so persistent in its attack that pear growing is becoming impossible. 



One large grower informed me in 1898 that he would cut down 

 all his pear trees in consequence and plant up apples, as he never got 

 any crop owing to the " midge." 



In 1906 there was some diminution in numbers in the Western 

 and Midland counties owing to the failure of the pear crop in 

 1905 (7). 



This small insect is a fly or " midge," belonging to the family of 

 Gall Flies or Cecidomyid?e and to the genus Diplosix, in which the 

 larva- or maggots have curious saltatory powers. 



It was described by Eiley (5) as Diplosis ftyrivora, but I see no 

 reason for this, as it is evidently the same as Meigen's Cecidomyia 

 nigra (1 and 2). 



Xorcllinger (3) describes it under the name Cecidumyia pyricola ; 

 Bergenstamm and Low (4) refer to it under Meigen's name, as do 

 many other authorities. 



The damage is done by the small white maggots feeding inside the 

 young pears and destroying them. 



The appearance of the infested fruitlets is very marked. About 

 two weeks after the attack has commenced they begin to swell 

 abnormally. The rapid growth compared with that of the sound 

 fruitlets is very marked. 



Later the fruit becomes deformed; some become round, others 

 bulge irregularly at the sides ; some become greatly elongated and 

 constricted in the middle ; in fact, all kinds of shapes are assumed by 

 them. 



On cutting open an infested pear one finds the inside more or less 

 hollowed out and filled with black debris and small white maggots. 



