PACKARD] INSECTS OF THE GARDEN. 37 



desert their leafy homes in autumn, iufesting every shrub, 

 tree and herb, and not content to pre}' upon tlie leaves and 

 bark, but even attackino; the roots of annuals and trees 

 alike, these little plagues are well nigh omnipresent. 



The naturalist Bonnet, as we have pre^'iously intimated, 

 discovered in 1742 the singular mode of reproduction in 

 these insects, by which we are enabled to account for their 

 enormous numbers. He discovered that the summer brood 

 of wingless individuals, or larvie, were born of virgin 

 mothers ; that their progeny gave birth to similar aphides, 

 and so on through the summer for nine generations, until 

 the original maiden aphis counts her children and grand- 

 children by millions. This large family thus launched into 

 the world are abundantly able to provide for their own 

 wants without the slightest anxiety to the maternal heart. 

 They at once, on being ushered into the world, plunge their 

 long beaks into the leaf or twig on which they crowd, 

 and there remain through their lives, leading a gluttonous 

 existence indeed, for when their stomachs are full they do 

 not have to rest awhile and sharpen their appetites for the 

 next meal, or resort to emetics, as in the palmy days of 

 Roman epicurism, but nature has provided them with two 

 safety valves, being two little tubes situated on the end of 

 the body. The liquid food or sap, after passing through the 

 alimentary canal, in part overflows through these tubes, as 

 a sweet exudation called honey dew. It may be seen drop- 

 ping on leaves, and sometimes solidifies into a solid whitish 

 sugar. 



Aphides are thus a great source of attraction to ants and 

 other insects, which visit them for the sake of this honoy. 

 Frequently the ants will stroke them and urge them to give 

 out their honey more rapidl}', hence they seem to milk them, 

 and the aphides are regarded as the ants' cows. Some utili" 

 tarian ants treat them as domestic cattle, herding them, and 

 even carry this care of their flocks so far as to take them up 



5 



