FIELD BOOK OF PONDS AND STREAMS 



Food. — The majority of the larvae feed upon leaves and root- 

 lets, diatoms and filamentous algas. Others like Limnophila 

 are carnivorous, feeding on blood-worms and small insects. 



Pupae. — When they are ready to transform, the larvae become 

 sluggish, quit eating, and transform into pale colored pupae. 

 Most cranefiies go on shore to pupate, burrowing in loose, 

 damp soil, and remaining there for about a week before the}" 

 emerge as adults. The following interesting account of their 

 emergence is given by Alexander in "The Cranefiies of New 

 York " (Bibliography, p. 420), "The emergence of the adults 

 usually takes place during the late hours of the morning, the 

 greatest number emerging between ten o'clock and noon. 

 When ready to emerge, the pupa pushes part of its body out 

 of the earth, the posterior two-thirds or half remaining at- 

 tached to the soil. If it projects farther than this, its trans- 

 formation seems to be a very difficult operation. The pupa 

 bends backward and forward constantly, flexing the body 

 dorso-ventrally. This motion appears to exhaust it, since it 

 frequently rests. The skin splits lengthwise up the mesonotum 

 (middle section of back of the thorax) and the adult emerges. 

 . . . The drawing out of the extreme tips of the antennas 

 is usually accomplished by the insect flexing its body back- 

 ward. When the antennas are freed, the insect walks a few 

 steps from the cast skin, withdrawing its abdomen from the 

 case." 



Hibernation. — Cranefly larvae can be found in brooks all 

 through the winter (PI. I). Alexander states that "it is 

 probable that nearh' all cranefiies in the north temperate 

 zone winter normally as larvce." 



Associates. — Cranefiies have many enemies in every stage 

 of their careers. The adults are poor fliers and are devoured 

 by many birds from water-fowl to warblers, by amphibians, 

 by spiders, and by other insects, especially dragonflies. 

 Pupae and recently emerged adults are seized by running 

 spiders; larvae are devoured by trout, by frogs and salaman- 



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