CECIDOMYID^. 



377 



Fig. 281. 



Walsh also 



Fig. 280. 



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



a, natural size; b, autenna; 281, gall) which is simply au 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 

 cabbage stalk. Mr 

 describes the Grape-vine Apple 

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

 pomum ; a, natural size ; b, a 

 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 ; 



b, 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 Cecidomjiaj 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 Cecidomj-ia and species of Scatopse and Drosophila, 



Fig. 282. 



