126 



THE BRITISH NATURALIST. 



[May 



This oviparous female is somewhat smaller than the first form and 

 darker in colour. This oviparous generation pair with the winged 

 males, and during the autumn deposit their black ova upon the twigs 

 and stem of the plum trees. Whilst digging during the winter at the 

 roots of the infested plum trees referred to, I came across several of the 

 wingless females hibernating in the soil, but whether these had sprung 

 from the autumn ova, or were the offsprings of the summer broods, I 

 cannot say, but I believe that in this and many other Aphides some of 

 the ova hatch during the late autumn, and the imagines coming from them 

 hibernate at the roots of the plants they infest. During April a large 

 number of forms have already assumed the pupal state, so we shall 

 have the winged females ready to pass from tree to tree and orchard to 

 orchard long before their normal time. 



From several localities I also hear that the Currant Aphis (Myzus 

 ribis ) is very plentiful, and I have observed it myself in exceptional 

 numbers at Kingston and Cambridge, both upon red and black currant 

 bushes. As a rule, I note this plant louse appears about the first week 

 in May ; this season I found many upon the young leaves as early as 

 April i st. The wingless female is pale green, spotted with dark green, 

 and somewhat elongate in form, with curious capitate hairs in front ; 

 legs yellow or green, and eyes reddish brown. The winged female, 

 which is of a bright greenish-yellow, is marked with black and dark green, 

 with black meso- and meta-thorax, and pale prothorax ; legs yellow and 

 brown. The male I have not seen, but Buckton figures it ; it is some- 

 what smaller than the female, and yellow with dark markings. The 

 wingless oviparous female is darker than the viviparous queen, and 

 appears late in the autumn. After having paired with the male she lays 

 her long eggs under the thin outer rind of the bark, attached to it by a 

 gummy fluid. Many I find are laid in the rough knots and burrs of 

 the red currant. It is generally noticed that when this plant louse is 

 upon the currant bushes the leaves become covered with red and 

 brown blister-like patches. These swollen cavities are the work of the 

 Currant Aphis ; by means of their beak they puncture and irritate the 

 tissues of the leaf, and so cause these gall-like swellings. Every now 

 and then the galls, instead of having the smooth red appearance generally 

 seen, become covered with a mass of green moss-like matter, especially 

 noticeable when the "lice" are very abundant. I find in this pest, 

 which is entirely destroying the leafage in some parts of the country 

 this year, that the pupal form has become abundant during the last few 

 days. Another common Currant Louse (Rhopalosiphum ribis, Linn.) is 

 also very abundant, and must not be confounded with the Myzus. 

 Two other fruit pests have been notified to me as being of a very 

 injurious nature this spring, in parts of Kent, Surrey, Cambridgeshire,' 

 and Somersetshire, namely, the larvae of the Winter Moth (C. bvumata} 



