APPLE SAWFLY. 11 



depending on difference iu methods of cultivation and nature of 

 ground) have been added, which are reported, together with the 

 description of the perfect Sawfiy, in the following pages. 



The general history of the attack, given in a few words, is, that 

 consequently on the insertion of the egg of the Sawfly (during the 

 blossoming time of the Apple) the Sawfly caterpillars hatch in the 

 young embryo Apple, and feeding therein grow with its growth, until 

 they cause much damage to the fruits thus infested, and sometimes to 

 others near, to which they have the power of straying at pleasure. 

 Presently they go down into the ground, form cocoons, turn within 

 them to the chrysalis condition, and thence to the perfect fly, which 

 comes out at tlie blossoming season of the Apples in the following 

 year. 



During the past season much fuller information than we possessed 

 before as to details of the above points (which we require for dealing 

 practically with the attack) were forwarded, especially in a series of 

 careful observations taken by Mr. W. Coleman, of Cranfield, Newport 

 Pagnell, Beds, which are given iu the following pages. In this will be 

 found many serviceable notes as, — the depth at which cocoons were 

 found beneath the surface ; also that though half-grown caterpillars 

 will bury themselves, they do not form cocoons ; that the appearance 

 of the Sawflies from the cocoons took place about the middle of May ; 

 that the method of attack as observed was for the egg to be inserted 

 into the calyx, or rather just below the calyx-leaves into the swelling 

 forming the future Apple, and the sign of attack having taken place 

 was a small orange-coloured mark. Also specimens of the perfect 

 Sawfly were forwarded, showing it to be the H. testudinea, and further 

 observation was sent of differences in marking of the caterpillar at 

 different stages of its life. 



Mr. Coleman's communications during the past season commenced 

 by a report sent me on Feb. 24th of the depth at which he found the 

 cocoons under special observation : — 



" A ten-inch pot was filled with earth from the soil surrounding 

 the Apple trees. A number of infested fruits were placed on the sur- 

 face of the soil, and allowed to remain until the caterpillars had fed 

 themselves to maturity, left the fruit, and burrowed down into the 

 earth in the pot. This was carefully turned out about a month after- 

 wards. The first cocoon lay at a depth of two inches, more at three 

 inches, and thickly at four inches, and in one instance the caterpillar 

 had gone down seven inches before laying up ; but this might be on 

 account of the soil being more friable and hollow than would naturally 

 occur in open ground in its natural state. For practical purposes the 

 depth may be taken as similar to that of other Sawflies of similar 

 habits, — Gooseberry, &c. 



