38 COLLECTING AND PRESERVING INSECTS. 



boxes and jars, multitudes of small flies will be hatched out. 

 Leaf-mining and seed-inhabiting species can be treated as 

 Microlepidoptera, and earth-inhabiting larvae like ordinary 

 caterpillars. Dung, mould in hollow trees, stems of plants 

 and toadstools, contain numerous larvae or maggots (Fig. 35) 

 as the young of flies are called, which must be kept in damp 

 boxes. 



Flies can be pinned alive, without killing them by pressure, 

 which destroys their form ; and numbers may be killed at once 

 by moistening the bottom of the collecting box with creosote, 

 benzine or ether, or putting them into a bottle with a wide 

 mouth, containing cyanide of potassium. Minute species can 

 be pinned with very slender pins, or pieces of fine silver wire, 

 and stuck into pieces of pith, which can be placed high up on 



Fig. 35. 



Onion Fly and Maggot. 



a large pin. In pinning long-legged, slender species, it is ad- 

 visable to run a piece of card or paper up under their bodies 

 upon which their legs may rest, and thus prevent their loss by 

 breakage. Of these insects, as of all others, duplicates in 

 all stages of growth should be preserved in alcohol, while the 

 minute species dry up unless put in spirits. 



COLEOPTERA. 



BEETLES. 



"Coleopterous insects may be distinguished by the hard 

 shell which incases their bodies ; the wings are protected by 

 horny wing covers, but in some the wing covers are small. 



