Tur CRANE-FiLIES oF New York — Part II 819 
Genus Dicranomyia Stephens (Gr. fork + fly) 
1818 Furcomyia Meig. Syst. Beschr. Zweifl. Ins., vol. 1, p. 106 (nomen nudum). 
1829 Dicranomyia Steph. Cat. Brit. Ins., vol. 2, p. 248. 
1830 Sitagona Meig. Syst. Beschr. Zweifl. Ins. ; or 6, pl. 65, figs. 5-7. 
1830 Glochina Meig. Syst. Beschr. Zweifl. Ins., vol. 6, p. 280. 
1854 Numantia Bigot. Ann. Soc. Ent. France, ser. a vol. 2, p. 470. 
Larva.— Form slender. Body nearly glabrous, abdominal and thoracic segments with 
dorsal and ventral transverse welts on basal annuli. Spiracular disk small, the five lobes 
indistinct but indicated, spiracles large. Anal gills four, slender. Head capsule massive, 
of the Limnobia type. Mouth parts almost as in Limnobia; ventral cutting edge of man- 
dible with fewer teeth; mentum with anterior margin more transverse and with fewer 
teeth. 
Pupa.— Cephalic crest lacking. Pronotal breathing horns broad, in D. simulans with 
a basal recurved hook on dorsal side, in other known species unarmed. Basal abdominal 
annuli with transverse welts. Dorsum of eighth abdominal segment with vestigial spiracles. 
Dicranomyia is a very extensive genus including more than two hun- 
dred described species of usually small flies which are found in most parts 
of the world. The immature stages, which are found in a variety of 
habitats practically as extensive as is covered by the entire family of 
crane-flies, range from forms that are almost strictly aquatic, thru species 
living beneath the bark of trees, to still other species which are leaf miners. 
in Europe, Dicranomyia trinotata (Meig.) is a characteristic member 
of the hygropetric association, the insects living on rocks in streams, 
where they are covered with a thin sheet of water and are usually asso- 
ciated with such insect forms as Beraea, Tinodes, Stactobia (Trichoptera), 
Orphnephila testacea (Ruthe), Pericoma nubila (Meig.), Dixa maculata 
Meig., Oxycera pulchella Meig., and other Diptera. The larva is cylin- 
drical, measuring from 10 to 11 millimeters in length and from 1.5 to 
2 millimeters in diameter. The dorsal surface is greenish mottled with 
darker, the ventral surface brighter. The larvae live in loosely spun 
silken cases in which they pupate. The pupae are about 10 millimeters 
Jong, and live in cocoons which are almost horizontal in position. The 
mature pupa breaks thru the cocoon by means of its sharp-edged breathing 
horns, the adult then creeping forth and leaving the cast pupal hull behind. 
(Thienemann, 1909:64-65, and Griinberg, 1910: 29.) 
Dicranomyia dumetorum Meig. lives in decaying, principally deciduous, 
wood. Winnertz (1853) found it in large numbers in a decaying beech 
tree, associated with Bremia cilipes (Winn.). 
