Reports to the Board of A griculture. 149 
Life-history. 
This aphis first makes its appearance in the early spring, when 
we observe small green lice here and there on the young leaves. 
These have come from eggs that have remained all the winter upon 
the plum trees. These lice rapidly grow into the wingless viviparous 
females, large Aphides, varying in hue from green to olive brown, 
and the abdomen with three faint green stripes ; antennae olive 
brown, cornicles brown ; the whole body above and below is covered 
with a mealv down. 
These apterous females soon commence to produce living young, 
which rapidly mature and produce other young. This asexual 
reproduction of wingless forms goes on for some time and under 
favourable conditions to such an extent that the leaves which have 
gradually curled up die off. As food supply commences to fail, 
these lice, instead of turning to wingless viviparous females, enter a 
pupal stage — rudiments of wings — “ wing-buds ” appearing. 
The pupa is shining green and dull yellowish, the wing-cases 
tipped with dark brown ; green cornicles also tipped with black. I 
have observed the pupal form in the first week in June, and again 
in J uly. Sometimes all on a tree enter this stage at once, at others 
only a few. 
The winged female coming from the pupa is also viviparous ; in 
colour she is apple green, with black head, thorax and antennae ; 
on the green abdomen is a dark patch and dark lateral spots ; the 
wings are iridescent with brown veins. 
These winged viviparous females fly about and settle upon other 
trees and set up fresh colonies, producing living young, which 
grow into apterous viviparous females which carry on rapid repro- 
duction like the first series. 
In the autumn the pupal stage is assumed again, but from the 
pupae now come winged males and wingless oviparous females. 
The winged male is small, and with a dusky ochreous body with 
dark brown head, markings on the thorax, and three on the abdomen. 
The colour varies considerably, some males being almost black, some 
wholly black, according to Buckton. 
The apterous oviparous female is pale yellowish-green, almost 
transparent, with brown cornicles. This female, after being fertilised 
by the male, deposits little shiny black eggs at the base of the buds 
and on the twigs. Egg-laying may commence early in October and 
goes on till November. These eggs usually hatch at the beginning of 
April, but I have observed the lice as early as March. 
