. Elementary entomology . Fig. 359. Pear midge [Di- plosh pyrivora). (Enlarged) (After Riley) Gall-gnats. The smallest and most deli- cate of the gnatlike flies are the gall-gnats {Cecidomyiidae). The adults are rarely over one eighth of an inch long, with long antennae clothed with short hairs, and with the wing-veins greatly reduced in number. They will be rarely noticed by the begin- ner, but the work of the larv^ is often much in evidence, owing to their feeding within the stems and leaves of plants and giving rise to galls. Frequently a green, cone-shaped gall is found on the tips of will
. Elementary entomology . Fig. 359. Pear midge [Di- plosh pyrivora). (Enlarged) (After Riley) Gall-gnats. The smallest and most deli- cate of the gnatlike flies are the gall-gnats {Cecidomyiidae). The adults are rarely over one eighth of an inch long, with long antennae clothed with short hairs, and with the wing-veins greatly reduced in number. They will be rarely noticed by the begin- ner, but the work of the larv^ is often much in evidence, owing to their feeding within the stems and leaves of plants and giving rise to galls. Frequently a green, cone-shaped gall is found on the tips of willow twigs, known as the pine-cone willow-gall, which is caused by one of these larvae {Cccidomyia strobiloides). The larvae of the clover-seed midge live in the heads of clover and destroy the seed so that in many sections it is often impossible to mature it. The best-known exam- ple of the family, an d our worst wheat pest, is the Hessian fly, so called be- cause it was sup- posedly introduced in straw brought over to Long Is- land by the Hes- sian troops during the Revolutionary War. The mag- gots bore into the crown and stalks of wheat, weaken- ing the plant and seriously curtailing production where they are abundant.
Size: 1739px × 2874px
Photo credit: © The Bookworm Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1, booksubjectentomology, bookyear1912
