THE CURRANT ROOT-APHIS. 169 



fifteen minutes after birth,"' and says it is in all probability a sexual 

 form. The figure looks just like an immature form of the asexual 

 generation j^roduced by the winged females I observed. 



I have never found centipedes affecting the nests of this aphide as 

 did Buckton. They were observed by him not to molest the schi- 

 zoneuras. 



The only record previous to Buckton's that I can find is in an old 

 work entitled "A Treatise on the Insects Most Prevalent on Fruit 

 Trees and Garden Produce," by Joshua Major, 1829. page 153. As 

 this work is now very rare I reproduce what is said of this currant 

 root-aphis : 



The roots of the currant bush, particularly the small fibrous roots, are some- 

 times infested by a small species of the aphides. It is smaller in size than any 

 of the preceding ones described. The body is of a buff or flesh color, produces 

 a cotton-like envelopment similar to the Aphis lanigera on apples, and which 

 probably might have been mistaken by Salisbury for the Eriosoma, or apple bug, 

 on the root of the apple tree, as I am almost persuaded that the Eriosoma, or, as 

 it is now called. Aphis laniyera, never feeds upon the roots, or at least after 

 many investigations I never found any feeding, or the least symptoms of their 

 having fed there. The attacks of the root-aphis are generally from the middle 

 of July to the latter end of September. At the last period they arrive at their 

 perfect or winged state. They prevail principally in dry weather. Tokens of 

 the visitations of these depredators are exhibited in the languishing or drooping 

 of the foliage, occasioned by the loss of the ascending sap, which they draw out 

 for their support. 



No mention is made of this pest by Kaltenbach, Taschenberg, or 

 more recent European writers, and I am not aware of its record 

 outside the British Islands. Neither Ormerod nor Whitehead has 

 referred to it, yet it is well known to many growers and gardeners. 

 Recently it has been recorded from Ireland, and I have observed it 

 in the northern part of Wales. 



The winged viviparous female varies in length from 1.70 to 1.80 mm., with 

 antennfe 0.70 to 0.80 mm., and a wing expanse of 5.50 mm. The general color 

 is dusky blackish-brown ; head and thorax rather shiny black ; abdomen deep 

 blackish-gray. The legs and also the antenn;p are shinv brownish-black. The eyes 

 are dull reddish and prominent. The antenna? (fig. 7) are composed of seven 

 segments, the two basal ones quite small, the second a little smaller than the 

 first and rounded apieally, the third segment very long with 18 prominent 

 rings projecting around the central stalk ; the base contracted; the apex normal, 

 rather swollen, a few scattered hairs in whorls between the rings ; fourth 

 segment small, narrowed basally, with two rings, the one apical ; fifth seg- 

 ment rather smaller than the fourth, narrowed basally, swollen apieally, with 

 a few hairs; the sixth closely applied to the fifth, about one-third the size; the 

 seventh much narrower than the sixth, about the same length (with traces of 

 three rings), and with numerous fine hairs. The rings apparently are only 

 on one side of the long segment, not completely encircling it (fig. 7, h). The 

 proboscis reaches halfway between the prothoracic and the mesothoracic legs. 

 Wings normal, the stigma ochreous-brown ; cubital vein stopping short about 

 the middle of the wing, forked once. Ungues large, expanded basally. 



The pupa (fig. 8) varies from 1.40 to 1.80 mm. in length, with antennae 0.30 to 



