CECIDOMYIM:. 



371 



Fig. 275. 



broods of the larvae, the first becoming fully grown the last of 

 April, the other the last of September, 6 



the flies appearing about the middle of 

 October. The larva (Fig. 275, a, en- 

 larged about three times, with the head 

 greatly magnified ; 6, the labrurn ; c, 

 the mandibles ; d, the labium) is cy- 

 lindrical, whitish and about a quarter 

 of an inch long. The single pair of 

 fore legs (Fig. 276a) are provided with 

 about twenty-five longitudinal rows of hooks, while the anal 

 legs (Fig. 277 ; a, a portion of the dorsal vessel) terminate in 

 a single crown of hooks which can be drawn 

 in out of sight. The worms were found either 

 creeping over the surface of the weeds, or if 

 about to pupate, concealed in a rude thin case 

 or tube, formed of the debris collected on the 

 weeds. It feeds on sea-weeds and small 

 worms. It remains in the pupa state (Fig. 

 276) about two weeks, transforming into a fly 

 (Fig. 278 male, and head of the female) which 

 differs from the true Chironomi in having 

 shorter antennae and smaller palpi, and also in 

 the venation, and the longer thorax. Tanypus 

 resembles Culex in its larva and pupa state, 

 being of similar form. Lyonnet figures a 

 larva which spins a movable case of silk and 

 moss. The eggs of T. varius are laid on the a 

 leaves of aquatic plants, and fastened together Fi s- 277. 

 with gluten. Some species of Ceratopogon, like the mosquito, 

 are blood suckers. The larvae are, however, terrestrial, living 

 in mushrooms, or under the bark of decaying trees. 



CECIDOMYID^E Westwood. The group of Gall-flies comprises 

 minute, delicate, slender-bodied species, whose bodies are 

 clothed with long hairs. The wings have usually three or 

 four longitudinal veins, and are folded over the back. 

 They are gall-flies, the female laying her eggs in the stalk of 

 cereals, and in the stems, leaves and buds of various plants 



Fig. 276. 



