42 
PEAR. 
SLUG-LEECH. PEAR-SLUG. (Selandria cerasi). 
In its larval state this sawfly is terribly destructive to the pear, 
plum, cherry, and hawthorn ; it may occasionally be found on the peach, 
apricot, and walnut, but rarely in sufficient quantity to cause much 
injury, although itis certainly becoming more frequent on the walnut, 
and occurring in larger numbers. 
The slug makes its earliest appearance on the leaves soon after 
midsummer, but in some localities it may be as late as March ; 
usually it occurs in vast numbers, several slugs being found ona 
single leaf. hee : 
The leaves are speedily devoured, and the fruit falls without 
ripening. In favourable seasons trees in a robust condition some- 
times produce a second crop of leaves, but these never attain their 
full size although they remain on the tree long past the usual time. 
The attack is repeated in following seasons, and after presenting a 
miserable appearance for some time the plant dies. 
The eggs of the sawfly are deposited on the upper surface of the 
leaf, and the slugs make their appearance in a few days, but require a 
month to, attain their full size; they are blackish-green in colour, 
rather more than half-an-inch in length, and consist of thirteen 
segments, the thoracic segment being the largest, and the abdominal 
segments gradually decreasing in size so that the larve present a 
clavate appearance. Jt is covered with a viscid slime, and emits a 
most unpleasant odour. Two rudimentary feet are carried on each of 
the three thoracic segments, and two sucker-feet on each of the 
abdominal segments except the first and the tail, so that the slug is 
twenty-footed. In about a month’s time the slug assumes the 
appearance of a buff caterpillar, and soon afterwards descends to the 
ground, where it enters the soil.and forms a small cocoon, in which it 
passes the dormant stage of its existence. 
Two broods are produced during the summer in the northern 
parts of the colony, and probably in some parts of the South also. 
An opinion prevails that the attacks of this insect are decreasing 
in severity, and that it makes its appearance later in the season than 
formerly. I believe a change is taking place in the date ofits first 
appearance, but I have seen no evidence to warrant the conclusion that 
its numbers are diminishing. 
REMEDIES. 
It is not diffici.1t to destroy the slug, although a little perseverance 
is often required to effectually clear the tree. 
The most popular remedy at this time is an infusion of white 
hellebore, made by pouring a gallon of boiling water over one ounce of 
the powdered herb, and allowing it to stand until cold, when another 
gallon of water should be added. The infusion may be used at once. 
It should be applied with a syringe or garden-engine. A weak 
solution of caustic potash would be even more efficacious. 
