CECIDOMYID J3 . 



377 



p. 105, the gall formed by C. strobiloides O. Sacken (Fig. 280 ; 

 a, natural size ; 6, antenna ; 281, gall) which is simply an en- 

 larged and deformed bud of Salix cordata. 

 The fly appears in April, or early in May, 

 oviposits in a terminal bud, and the gall attains 

 its full size by the middle of July. The larva 

 hibernates in a thin cocoon, changing to a pupa 

 in the spring. (Walsh.) Another willow gall 

 made by C. salicis-brassicoides Walsh occurs 



on the Salix longi- 

 folia, the galls 

 forming a mass 

 (Fig. 282) like 

 the sprouts on a Fig. 281. 

 cabbage stalk. Mr. Walsh also 

 describes the Grape-vine Apple 

 Gall (Fig. 283, gall of C.? vitis 

 pomum ; a, natural size ; 6, a 

 2so. section), the fly of which is 



unknown. The gall is divided into numerous cells, each con- 

 taining a larva. It occurs on the wild Frost grape. The 

 Grape-vine filbert gall (C.? vitis-cory- 

 loides Walsh, fig. 284 ; a, head of larva, 

 showing the clove-shaped breast bone ; 

 6, a bunch of galls, natural size ; c, sec- 

 tion of a gall, showing the cell the 

 larva inhabits) is found on the wild 

 Frost grape in Illinois. 



Walsh has described fourteen addi- 

 tional species of Cecidomyise inhabiting 

 eight different species of willow. The 

 specific character of the insects them- 

 selves, are in all their stages of the 

 slightest possible character, but the dif- 

 ferent galls can be readily distinguished. 

 These galls, according to Walsh and 

 other authors, also afford a shelter to so- 

 called "inquiline," or guest species, such as the larvae of other 

 species of Cecidomyia and species of Scatopse and Drosophila, 



282t 



