80 _ PEAR. 



observing them, the numbers have been small. This difference in 

 amount is noticed by Mr. Cameron,* who (besides reference to their 

 occasional appearance in great numbers, "as they unfortunately too 

 often do ") writes of their more ordinary infestation as follows : — " The 

 larvae feed on the upper side of the leaf, usually to the number of three 

 or four. They eat only the upper epidermis ; at first the leaf gets 

 eaten in patches, but ultimately every particle of green is devoured, so 

 that it has the appearance of having been scorched, and ultimately it 

 falls to the ground." ..." The damage done by these ugly 

 brutes to fruit trees is very often immense ; especially is this the case 

 during very dry seasons. They are found on most species of Pyrus, 

 Primus, Cerasus, Piubus, and Amygdalus, as well as Cratagus, Quercus, 

 and Betula."—(P. C.) 



Of the above list, the three first, the Pear, Plum, and Cherry, are 

 the most important for garden consideration, and it has never chanced 

 to me to meet with them on the three last named, the Hawthorn, Oak, 

 and Birch. 



The grubs are, in the greater part of their lives, of the shape 

 figured at p. 79, that is, both broader and thicker at the fore part of 

 the body, and altogether somewhat pear-shaped, but covered with a 

 shiny blackish slime, or exudation, which gives a strong resemblance 

 to a little black Slug, or perhaps still more to a bit of wet black dirt 

 fallen on the leaf. At the last moult the grubs throw off the black 

 slimy coat, and appear as yellowish caterpillars transversely wrinkled. 

 After this change they soon go down into the ground, where they spin 

 small black or brown cocoons, from which (in ordinary course) the 

 Sawflies come out early in the following summer. 



The flies are of the shape figured at p. 79, black, shining, the 

 female sometimes tinged with violet ; the " wings hyaline, with a 

 broad smoky band in the middle." 



The first communication of last season regarding Slugworms was 

 sent me on the 14th of June, from Neasham Hill, Darlington, by Mr. 

 R. Cresswell Ward, with some Pear leaves accompanying, which gave 

 me the opportunity of observing the young Sawfly maggot whilst still 

 in the egg. Mr. Ward wrote : — " Can you tell me what is the insect 

 enclosed ? It appears to me to be a kind of black Slug. For the past 

 three years it has come on my Pear trees about this time of year. It 

 eats all the upper skin off the leaf, which turns brown and drops off; 

 all the strength appears to go from the trees, which have hardly 

 fruited since it began. I tried syringing with paraffin, water, also 

 soap-suds, last year, and this year my gardener painted the stems and 



* See ' Mon. of the Brit. Phytophagous Hymenoptera,' by Peter Cameron, vol. i., 

 p. 225. (Ray Society). 



