48 Second Report on Economic Zoology . 
clusters turning brown and dying away. The pupae, I find, require 
nourishment, just as much as the larvae. The adult Psylla is of a 
general green colour, with shades of pale apple green and yellow, but 
previous to pairing they become variegated with red and rusty brown ; 
the legs are yellowish green, and the antennae, which are bifid at the 
tip, are dark apically. The female is about one-tenth of an inch 
long, the male somewhat smaller. The eggs, which appear to be 
spindle-shaped, have really one end prolonged into a thread-like 
appendage ; they are mainly laid on the young wood, especially 
amongst the fine hairs, but now and then in cracks and crevices in 
the bark. Several are generally laid together in rows, but also 
singly. They commenced to lay them in September, but went on 
to November. They remain on the trees all the winter. The 
larvm are flat and of a dusky yellowish-brown, with brown spots 
and red eyes, the legs dusky. In about ten days after they have 
come from the egg they moult, and a curious blue thread or threads 
issue from the end of the body, attached to which is a round opaque, 
oil-like globule. These globules frequently become detached, and 
remain on the leaves, as pointed out to me by Mr. Cecil Hooper 
during the past season. In about ten days later the larva casts its 
skin again, becomes green, and often is covered with fine pale blue 
threads, which are almost white in certain lights. Another change 
takes place, and the pupal stage is reached about a week later. The 
pupa is also flat, green in colour, with dark eyes, and the apices of 
the antennae dark, and very prominent wing-buds are formed. The 
pupae give rise to the adults in June, as a rule, but the change 
may take place later. The curious jumping habit of the adults 
frequently causes them to be mistaken for “ frog-flies ” ( Euacantliidee ). 
Treatment. 
Soft soap and quassia has until this year been found effective in 
checking the damage caused by this pest. But, from a letter 
received in answer to a communication to the Herefordshire Fruit- 
growers’ Association, it has not been so during the past season. 
Much benefit has been found from the use of caustic alkali wash in 
winter. Hard pruning and burning the shreddings at once also 
lessens the numbers. Autumnal washing with paraffin emulsion has 
been found to kill the adults, and if done in time will prevent egg- 
laying. The wash may be made at full strength as the foliage will 
not then be hurt. 
