52 



slug and winged state. Professor Peck has described a minute ichneumon fly, stated by Mr. 

 Westwood to be a species of Eneyrtus, that stings the eggs of the slug fly, and deposits in 

 each one a single egg of her own. From this in due time a little maggot is hatched, which 

 lives in the shell of the slug-fly's egg, devours the contents, and afterwards is changed to a 

 chrysalis, and then to a fly like its parents. Professor Peck found that great numbers of the 

 e^s of the slug-fiy, especially of the second hatch, were rendered abortive by this atom of ex- 

 istence. 



Sand, ashes, lime and hellebore have been recommended as remedies for this pest but the 

 last mentioned is by far the most reliable. In 1870 we tried some experiments with these rem- 

 edies, and reported in the Canadian Entomologist for September of that year, as follows : — 



The Pear Tree Slug. 



This disgusting little larva, the progeny of a little blackish sawfly, has been very abun- 

 dant during the past season and has been the subject of some notes and experiments. In the 

 first place we noted that there were two broods in the season. The parents of the first brood, 

 which pass the winter in the chrysalis state, appeir on the wing about the second or third 

 week in May, depositing eggs from which the slugs are hatched, becoming full grown from 

 the middle to the end of June, then entering the chrysalis state underground ; the second 

 brood of the flies make their appearance late in July. This year we noticed them at work 

 depositing eggs on the 21st, the young slugs were abundant and about a .(uarter of an inch 

 long on the eighth of August and by the sixth of September many of them were full-grown. 

 With us they were much more destructive to cherry trees than to pear, consuming the upper 

 surface of the leaves, soon giving the trees a scorched and sickly aspect, and in many cases 

 the foliage fell off, leaving the trees almost bare. 



As soon as the slugs were observed at work in 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 

 through 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 

 dos 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 efiectual, but having none on hand just then, 

 the experiment was postponed, and the opportunity of testing it lost for the season. We 

 must not omit mention of an experiment with hellebore. On the 13th of August, at eight 

 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 thickly 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 

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

 TMnained alive the following morning, aud these soon after died. 



During the past season these slug worms have been unusually abundant on our pear 

 ftrees, in many cases destroying the foliage so thoroughly that they looked as if they had been 

 seorched by a fire, every leaf in some instances dropping from the trees, so that for a time they 

 weie bare as in mid-winter. Nearly a thousand trees in the young pear orchards of the 

 writer suffered severely. During the latter part of June and the early days of July we had 

 no opportunity of inspecting these trees, and when we visited them on the 7th of July they 

 were so much injured that we thought they could not be much worse, and as the slugs were 

 then full-grown and fast disappearing and the application of a remedy to so many trees a 

 matter of much labour nothing was attempted to remedy the evil then. 



It was observed that some trees were remarkably exempt from the attacks of these slugs 

 Clapp's favourite deserves to be especially mentioned on this account, its thick glossy leaves 



