VII 



CECIDOMYIIDAE 



459 



Cecidomyiids. The Xorth American Diplosis resinicola lives in 

 the resin exuded as the results of the attacks of a caterpillar. 

 The larva burrows in the semi-liquid resin, and, according to 

 Osten Sacken, 1 is probably amphipneustic. Cecidomyiid larvae 

 are short maggots, narrowed at the two ends, with a very small 

 head, and between this and the first thoracic segment (this bears a 

 stigma), a small supplementary segment ; the total number of seg- 

 ments is thirteen, besides the head; there are eight pairs of stigmata 



FIG. 219. Ci'fiilomyia (Diplosis) buxi. 

 Britain. A, Larva, magnified ; B, 

 pupa ; C, imago ; D, portion of an- 

 tenna. (After Laboulbeue.) 



FIG. 220. One segment of an- 

 tenna of Xy/i'iHji/ux/x sp. ; a, 

 Tip of one segment ; b, base of 

 another. (After Janet.) 



on the posterior part of the body. Brauer defines the Cecido- 

 myiid larva thus, " peripneustic, with nine pairs of stigmata, the 

 first on the second segment behind the head ; two to nine on fifth 

 to twelfth segments ; body as a whole fourteen - segmented 

 without a fully-formed head." The most remarkable peculiarity 

 of Cecidomyiid larvae is that those of many species possess a 

 peculiar organ called breast-bone, sternal spatula, or anchor- 

 process projecting from the back of the lower face of the pro- 

 thoracic segment. The use of so peculiar a structure has been 

 much discussed. According to Giarcl, 2 in addition to the part 

 1 Tr. Amcr. ent. Soc. iii. 1S71. p. 345. - Bull. Soc. cut. France, 1893, p. Ixxx. 



