Mr. CuRTis's Ohfervattotii on Aphides. gx 



Aphides, while at their higheft point of multiplication, do not fwarm 

 like bees or ants, and fly off or emigrate in large bodies; but each 

 male or female ylphis, at fuch periods as they arrive at maturity, 

 marches or flies off without . waiting for any other. Yet it may 

 happen that, from a tree or plant thickly befct with them, numbers 

 may fly off or emigrate together, being arrived at maturity at the 

 fame moment of time. 



Detaching itfelf from the plant, each purfues a different route, 

 intent on the great bufmefsof multiplying its fpecies ; and fettles on 

 fuch plants in the vicinity as are calculated to afford nourifhment 

 to its young. 



The common green Aphis, which is fo generally deftru6live, lives 

 during the winter feafon on fuch herbaceous plants as it remained 

 on during the autumn, either in its egg or perfect ftate. If the 

 weather be mild, it multiplies greatly on fuch herbage; as the fpring 

 advances, in May the males and females of thefe infects acquire 

 wings : and thus the bufmefs of increafe, hitherto confined, is widely 

 and rapidly extended, as the winged Aphides, by hop- planters called 

 the Fly, may be feen from this period very generally fitting on plants, 

 and floating in the air in all direftions. 



Minutes of Appearances obferved in the Aphis falicis from the End of 

 September to December 6th. 



The Aphis falicis is among the largeft Englifh fpecies, and is found 

 on the bark both of the trunk and branches of the Salix trlandra, 

 fragilis, and viminalis, but moft abundantly on the lafl. The 

 bodies of thcfe infe£ts contain a red liquid, and hence perfous em- 

 ployed in (tripping ofiers have their hands rendered apparently 

 bloody by unavoidably bruifing theno. 



Near the end of September multitudes of the full grown infects 

 of this fpecies, both winged and others, are obferved to defert the 



N a willows 



