44 ' NEW YORK STATE MUSEUM 



coarsely shagreened; posterior extremity broadly rounded and with 

 a pair of submedian processes, the latter irregularly subcorneal and 

 indistinctly segmented. 



Life history. Material obtained from Rhode Island in 1910 pro- 

 duced niimerous midges the latter part of May, which is probably 

 about the time that the flies might be expected to issue in Long 

 Island localities. The observations of Professor Chaine, extending 

 over a period of three years at Bordeaux, France, showed that the 

 earliest pupae were observed from the ist to the 25th of March, the 

 earliest adults appearing from the 24th of March to the i6th of April. 

 His investigations demonstrated that the period of oviposition lasts 

 two to three weeks, the female normally selecting the younger leaves 

 and depositing the eggs singly at a distance from each other and in a 

 small slit cut by the bladelike ovipositor. Doctor Laboulbene, after 

 studying this insect in Paris, states that the adults appear from 

 early to the middle of May. Professor Chaine obtained no evidence 

 of the midges feeding, though he observed that they were strong 

 flyers, since they were found two hiuidred meters from the nearest 

 box and at a height equal to the first story of a house. 



The first indications of attack, according to Professor Chaine, are 

 very small, rounded points on the under side of the leaves, indicated 

 only by a slight change in color. There is a slight increase in the 

 size of the discolored areas during the first week of June, and the 

 second week a small, yellowish spot may be visible upon the upper 

 surface of the leaf, and on the under side there is a relatively great 

 development due to the young maggots enlarging their mines. These 

 latter increase in size and a week or two later may extend to 

 the edge of the leaf and become confluent. As a result, infested 

 leaves in September and October show one or more large mines 

 inhabited by two to three or more larvae. Frequently most of the 

 tissues on one or both sides of the leaf may be attacked by these 

 maggots, though as a rule the mines on opposite sides of the midrib 

 do not coalesce. Winter is passed in these shelters, the larvae 

 transforming to pupae and the latter partly issuing through a cir- 

 cular hole prior to the appearance of the parent fly the latter part of 

 May or early in June. There appears to be but one generation 

 aimually. 



Natiiral enemies. A nimiber of gall midges, at least, are 

 subject to attack by nattual enemies, though as yet we have been 

 imable to obtain any parasites from this species. There is a record 

 of M. Decaiix ha^dng reared one Chalcid, species undetermined. 

 The mere fact that there are records of severe injuries in Europe by 



