DIRECTIONS FOR COLLECTING AND PRESERVING 



DIPTERA. 



For catching dipterous insects, use nets, like those employed 

 in catching butterflies. 



The best way of preserving diptera after having caught them, 

 is to pin them immediately. A slight compression of the chest 

 between the fingers is sufficient to kill without crushing them. I 

 prefer rather short pins, but their thickness ought to be in pro- 

 portion to the size of the insect. When pinned, the insect must 

 be a little above the middle of the pin. 



Diptera do not keep well in spirits. This mode of preserving 

 should, therefore, be recurred to in cases only when no other can 

 be conveniently used. 



