360 



PROTKCl'ION AGAINST INSECTS. 



B. Diptera. . 



Family I. — Cecido.myiidae (Gall-gnats). 



Flies with long thread-like or moniliform antennae, with 

 10 to 3G joints, usually with 

 whorls of hairs ; hody delicate ; 

 wings moderately large with 

 rounded anterior border, con- 

 stricted at the base, often 

 iridescent, with 3 to 5 longi- 

 tudinal veins ; abdomen cylin- 

 drical, consisting of 8 segments, 

 in ? pointed and often furnished 

 with a projecting tubular ovi- 

 positor ; legs slender, the tibiae 

 unarmed at apex. 



Larvae long fusiform legless 

 maggots, slightly flattened, with- 

 out chitinous mouth -armature, 

 jjut with a chitinous fork or 

 " anchor-piece " eml)edded in 

 the skin of the ventral surface; 

 usually pale yellowish or reddish. 

 The iiiiagos lay their eggs in 

 needles, leaves or bark, in 

 which the young larvae feed by 

 sucking, and thereby cause gall- 

 like swellings. 



Fie. 187.— Larch twier, with trails ,, , 



made by c. Mneri, Suschl. ' ^^veral species are common 



iNaiural she.) On willoWS. 



1. Cecidomyia salicij^erda, Duf. {Willoir GaU-fiuat). 

 (I. Deficrijilidn. 

 i'V// 2 to 8 mm. long; black-brown; the wings milky-white 

 with whitish hairs ; antennae shorter than tiic body. 

 Larva yellowish red. 



//. Life-ltislorji, dr. 

 The eggs are laid during i\[ay in rows on the Itark of the 

 branches up to the thickness of one's arm of pollard-willows 



