THE PEAR MIDGE. 45 



appearance (Fig. XXIII, I 3), at the same time they grow more 

 rapidly than the uninfested fruitlets. 



The larvae gradually eat their way into the core of the 

 fruitlet, tunnelling the fleshy pulp in all directions. If one of 

 these fruitlets is now cut open it will be found to contain fifteen 

 to twenty small white or yellowish-white maggots, surrounded 

 by a mass of soft pulp and excremental pellets (Fig. XXIII, 3). If 

 one is cut open a little later it will be found that nearly all the 

 interior of the fruit has been consumed and that the larvae are 

 now full grown, measuring about one-sixth of an inch in length 

 (4 to 4.5 millim.). 



Early in June they commence to leave the fruit. This 

 usually takes place while the pears are on the trees, but in some 

 cases they fall to the ground and the larvae then leave them. 

 In either case they leave the fruit by some crack or decayed 

 portion, preferably during or immediately after rain, possibly 

 they are driven out by the rain making its way into the fruit. 

 Messrs. Coe, whose orchards were the first ones attacked in 



2 

 I 



1 



FIG. XXIII. THE PEAR MIDGE (Diplosis pytiuora). 

 i and 2. Distorted pears containing larvae. 3. Section showing larvae within. 



America, state, in writing to Dr. Riley ( T ), "Our men had 

 gone over the orchard once, picking all that they could find 

 and were going over it a second time when a violent rain storm 

 obliged them to quit for an hour or two. Returning after the 

 rain they observed that a basket that had been left out in the 

 storm with two or three quarts of the worty pears was alive 

 with the larvae, hopping about like so many fleas. They had 

 all left the fruit and were trying to escape from the basket. 

 Upon examination, we found that the infested fruit on the 

 trees had no larvae. So the work was not so thoroughly done 

 as we had intended." 



Like other species of the same genus, the larvae progress 

 by skipping or jumping, which movements are effected by 

 curving the posterior part of the body downwards until it reaches 

 the first thoracic joint, at the same time the anterior end of the 



I. Ann. Rpt. [U.S.] Comms. Agric. for 1885, Washington 1886. Rpt. of the Entomologist, p. 284. 



