THE PEAR SLUG. 523 



then yellow and free from mucus. From the first of July to the middle of August, 

 having gained their growth, they leave the trees and burrow to the depth of 1 to 

 4 inches, forming an oval cavity in the earth, where the change to pupa occurs. 

 From these cells they escape in the form of saw-flies from the middle of July to the 

 last of August. The winged insect is about one-fifth of an inch in length, and is of 

 a glossy black color, excepting the first two pairs of legs, which are a dirty yellow 

 or clay color, with blackish thighs, and the hind legs, which are dull black with 

 clay-colored knees. The wings are transparent, iridescent, with brownish veins, and 

 with a smoky cloud or band across the middle of the third pair. These saw-flies may 

 be found on the leaves of the trees in early morning or in the cool of the evening, at 

 which time they are sluggish and not easily disturbed. Their eggs are laid singly 

 within little somi-circular incisions through the skin of the leaf. From these a 

 second brood of the slugs soon hatch, which get their growth and go into the ground 

 again in September and October, remaining there until the following spring, when 

 most of them are changed to flies and leave their winter quarters. Some of them, 

 however, commonly remain unchanged in the ground until the following year, so as 

 to continue the species if any complete destruction should overtake the remainder of 

 the brood. These spring flies lay their eggs as already described, usually in June, 

 the minute worms appearing in about a fortnight afterwards. 



Remedies. — Various substances have been suggested for the destruction of this pest, 

 but unfortunately some of those most generally recommended have really little 

 efi"ect. Among these remedies of doubtful efficiency I may mention fine sand, and 

 dust and ashes. Some experiments made with these substances by Mr. William 

 Saunders, of Ontario, Canada, are worth quoting entire : 



" As soon as the slugs were observed at work in the spring, they were treated to a 

 plentiful supply of dry sand, thrown up into the higher branches with a shovel, and 

 shaken over the lower ones with a sieve, which stuck thickly to their slimy skins, 

 completely covering them up. Thinking we must have mastered them by so free a 

 use of this long trusted remedy, we took no further heed of them for some days, 

 when, to our surprise, they were found as numerous as ever. The next step was to 

 test this sand remedy accurately to see what virtue there was in it. Several small 

 branches of pear trees were selected and marked, on which there were six slugs, and 

 these were well powdered over— entirely covered with dry sand. On examining 

 them the next morning it was found that they had shed the sand-covered skin and 

 crawled out free and slimy again. The sand was applied a second and third time 

 on the same insects with similar results, and now being convinced that this remedy 

 was of little value, they were treated to a dose of hellebore and water, which soon 

 finished them. Ashes were now tried on another lot, the same way as the sand had 

 been, with very similar results. It was also intended to try fresh air-slacked lime, 

 which we believe would be effectual, but having none on hand just then, the experi- 

 ment was postponed and the opportunity of testing it lost for the season." 



A far more serviceable remedy is powdered hellebore, and an experiment with this 

 by the same entomologist is equally conclusive : 



"On the 13th of August, at 8 a. m., a branch of a cherry tree was plucked, on 

 which there were sixty-four slugs ; the branch had only nine leaves, so that it may 

 be readily imagined that they were thick>y inhabited. A dose of hellebore and 

 water was showered on them about the usual strength, an ounce to the pailful, when 

 they soon manifested symptoms of uneasiness, twisting and jerking about in a curious 

 manner; many died during the day, and only six poor, sickly-looking specimens 

 remained alive the following morning, and these soon after died." 



Unquestionably, Paris green or other arsenical poisons would be equally eflfective 

 if applied to either brood of the worms ; but if the trees were bearing, its use would 

 of course be inadmissible except for the second brood. Some have also recommended 

 shaking the flies down from the trees early in the morning, or late in the evening, 

 catching them on cloths and taking care to destroy them before they can escape. 



