248 



Insect Pests. 



small twiss and buds. In tliis positimi they remain until the buds 

 of the damson burst in spring. The earliest date I have noticed them 

 hatch out is the 29tli of March. That is later than the hatching of 

 the true plum apiiis. 



Not only are these ova laid on the damsons and now and then 

 plums, but also in numbers on the sloe ; in fact, the damson and sloe 

 are most affected. During the autumn vast swarms of tlie hop aphis 

 cover the leaves of all prunes, yet but very few eggs are detected on 

 plum trees and greengage, whilst the damsons are literall>" covered. 

 If damsons and sloes exist in the neighbourhood they are used as 

 winter egg quarters in preference to any other prunes. The planting 

 of damsons without any necessary checks has been a means of increase 

 for the hop aphis. (Jn these trees the ova hatch out in sprin.u into 



lice, which speedily grow into w mgless and \-i\-iparous female.- : these 

 are sometimes spoken of as "(lueen-" or "stem-mothers." These 

 wingless females produce Ining young like tliemselves, and suck 

 out the sap of the young damson leaves, often rausinu untold 

 damage, and the lilossom may sutler. Thev can at ouce"^ be cold 

 from the I'lum Aphis (J. pnnii), by tlie snurll processes on the 

 head shown in the figures. Some authorities have considered ihis 

 prune-hop aphis a distinct variety, known as varietv nnn,,]nl: there 

 IS no reason for giving it another name, it .is die same aiihis 

 although the anteunal swellings are not so developed on the ,lams,,n 

 as when it is on the hop,s. On the pruu.v. there seem I,, l,e nornnllv 



