366 The Rose Garden. 



appearing in June and September. Specimens of the first brood are very rapid in their trans- 

 formations, seldom taking more than four or five weeks to accomplish the full term of their 

 existence. When full fed they descend into the earth, and there pass into the pupa state, the fly 

 emerging in July or August from the summer brood, and in the spring from the larvae of the 

 preceding autumn. It is a thick-bodied fly ; the head and thorax are black, body yellowish 

 brown. It is not so active as many kinds of saw flies, the female being especially easy to 

 capture and destroy. 



It is not at all an unusual circumstance to find a number of large round holes eaten in the 

 leaves of a favourite Rose tree, the edges being left untouched. If the leaf so disfigured be 

 turned over there will often be found reclining at full length underneath a small pale green 

 caterpillar, the larva of a saw fly, called Tenthredo (or Cladius) difformis. This caterpillar is 

 easily distinguished from the other saw fly larvae which feed upon the Rose by the fact of its 

 being flatter and not so plump in appearance, and another characteristic peculiar to it lies in a 

 row of small excrescences down each side, which give it a notched appearance, and from each of 

 these excrescences proceeds a tuft of small whitish hairs. When full fed it measures about half 

 an inch ; colour as before stated, pale green with a darker stripe longitudinally down the back ; 

 the head is brown. When disturbed it falls quickly to the ground, often rolling itself into a 

 ring. When full fed it rolls up a small piece of the edge of the leaf and spins itself a small 

 white silken cocoon in which it passes to the pupa state. The fly is about one-sixth of an inch 

 long and one-third of an inch in the expansion of the fore wings. It is slender in form ; the 

 body is black and shining; the legs yellowish white, and black at the base; the wings are 

 pale smoke coloured. The antennas of the male when viewed under the microscope will be 

 found to be branched somewhat resembling a stag's horn ; those of the female are quite thread- 

 like, and it is to the difference of the two sexes in this respect that it probably owes its specific 

 name. The larva is common in June and throughout July ; the fly in July and August. 

 Mr Westwood states that this caterpillar is especially attached to standard Rose trees. 



In a comprehensive, although not perhaps full, account of insects injurious to the Rose, 

 which appeared sometime since in The Garden newspaper, mention is made of the Saw Fly 

 Tenthredo (Athalia) rosce. In this neighbourhood, as far as our observations have gone, the 

 Rose seems to be exempt from its ravages ; but as all localities are not so favoured, a short 

 account of it may not be uninteresting, but the greater part of the facts are drawn from the 

 article above alluded to. The parent fly deposits her eggs on the mid-rib of the Rose leaf, and 

 the young larvae emerging attack the upper surface of the leaf, leaving the under surface 

 untouched and quite transparent. When full grown the larva is of a dark green colour, paler 

 at the sides and underneath ; head yellowish brown. It descends into the earth for the purpose 

 of changing to a pupa. The fly is described as thick bodied, with the head and thorax black 

 and the body yellow. It is double brooded, the caterpillar appearing in June and July and 

 again in the autumn, the fly during Jiily and August, and specimens from the autumn larvae in 

 the spring. With this species our notes on Saw Flies are brought to a close. There are one or 

 two more species which will be found perhaps occasionally on the Rose, but they are either of 

 such rare occurrence generally, or upon Rose trees specially, that they are hardly worthy of 

 particularisation from our point of view. 



The Gall Flies are the next class of HYMENOPTEROUS insects which come under our notice. 

 Although the mischief they cause is very slight indeed in comparison with that effected by some 

 insects, and many of their dwellings may be looked upon almost as objects of beauty and 

 ornamentation, nevertheless their existence on a plant exercises a baneful influence on its 

 welfare. Everybody has probably observed on the young branches of the Dog-Rose or Sweet 

 Brier, during the summer and autumn months, globular masses resembling bunches of moss. 

 In the summer they are of a bright apple-green colour, but as the shortening days of autumn 



