Tipuloidea 3 73 



GROUP II. IMMATURE STAGES INHABITING SATURATED SILT, MUD, OR SAND 

 Representative genera, subgenera, or species: Non-predacious larvae— 

 Erioptera (all subgenera), Gonomyia, Helius, Helobia, Molophilus, Ormo- 

 sia, Pseudolimnophila, Tipula annulata, T. jacobus, T. sayi, T. subeluta, 

 T. synchroa, T. tricolor, Trimicra. 



Predacious larvae — Adelphomyia, Hexatoma (Eriocera) albitarsis, Lasi- 

 omastix, Phylidorea, Pilaria, Polymera, Ulomorpha. 



Here, perhaps more than in any other group, silt, mud, or sand from 

 the larval habitat is likely to contain the immature stages of several 

 species of craneflies as well as various predators upon them. If it is 

 only desired to carry late larvae through to the adult stage, the wet silt, 

 mud, or sand may be placed in a layer an inch deep on top of a layer 

 of coarse wet sand in the rearing jars and pasteurized. When cool, any 

 loss of water should be made up and the larvae introduced into the jars. 

 If younger larvae or eggs are to be reared, or a continuous culture is to be 

 maintained, the silt, mud, or sand should be washed through a wire sieve 

 of 12 to 16 meshes per inch into a jar of water. When the material has 

 settled* the water may be decanted and the semi-fluid silt or muddy sand 

 may be placed in a layer an inch deep on about an equal depth of coarse, 

 wet sand in the rearing jars. (A cylindrical glass jar, 150 x 150 mm., 

 Y 4 filled with sand and silt, is of ample size for a score or more of Eriop- 

 tera larvae.) Some small green plants that will thrive in the wet silt or 

 sand should be provided, but not allowed to choke the surface. Small 

 pond-margin grasses (Websteria), Hydrocotyle, and silt-inhabiting liver- 

 worts and algae have been used successfully in rearing Erioptera, Molo- 

 philus and Pseudolimnophila. It is important to keep very nearly satu- 

 rated cultures in which fine silt is the medium. Once the surface becomes 

 dry it is likely to acquire a texture that prevents the larvae from reaching 

 the air with their respiratory disks. 



Predacious larvae require much the same culture conditions but should 

 be isolated. Several living Erioptera or Pseudolimnophila larvae, some- 

 what smaller than the predacious larva, or some small aquatic or silt- 

 inhabiting annelid worms should be dropped into the jar once or twice 

 a week. 



GROUP III. IMMATURE STAGES INHABITING WET TO DAMP SOILS 

 Representative genera and species: Cladura, Dactylolabis cubitalis, 

 Dicranoptycha, Nephrotoma eucera, N. jerruginea, N. macrocera, Tipula 

 bicornis, T. borealis, T. dietziana, T. disjuncta, T. dorsomaculata, T. du- 

 plex, T. fuliginosa, T. georgiae, T. grata, T. oxytona, T. perlongipes, T. 

 triplex, T. triton. It is probable that many Nephrotoma and a large 

 majority of the species in the subgenera Oreomyza and Lunatipula of 

 Tipula belong here. 



*Small larvae or other arthropods that pass through the sieve usually soon rise to the 

 surface of the water where they may easily be seen. 



