ENTOMOLOGICAL SOCIETY OP ONTARIO. 21 



Rose Saw-flies. 



A new saw-fly made its appearance this year upon my roses, so that there are now 

 three species attacking these favorite plants. One of tlie^e ha-^ been known for many 

 years to the lovers of the rose as a troublesome pest, which rapidly destroys the foliage if 

 not promptly looked after. This is Monostcgia rosa;, Harris, described in 1841 and then 

 placed in the genus Selandria, which has since been sub-divided. Although named in 

 America there is very little doubt that it came from Europe, where it is well known as a 

 troublesome insect, and where several names have been sul)se(juently bestowed upon it. 

 The small stout black flies are abundant in May and June, and the eggs are deposited in 

 the under surface of the leaf, generally near the edge* The slug-like larvte feed, at 

 night, upon the upper surface of the leaf and cause it to l)eoome brown and withered. 

 In about a foitnight they are fully grown and drop to the ground in which they con- 

 struct an earthern cell to shelter them until they pupate and emerge the following May 

 or June. There appear to be but two mentions of this saw-fly in our reports : The first 

 by Mr. Gott, of Arkona, in 1878 (Ann. Rept. No. IX, page 57), who stated that it was 

 becoming very abundant and troublesome; the second in my paper on Saw-flies (Ann. 

 Rept. XV, page 70) where its habits are concisely stated. 



The second of our pests has not been long known to us, as such, but probably it crossed 

 the ocean maijy years since, as it was named by Harris about fifty years ago as a new species. 

 This insect is called Cladiua pectinicornis, Fourc..(C. isomera, Harris), and its larva may 

 be called the Bristly Rose-worm to distinguish it from that of the previous species. Dr. 

 Riley, in an interesting article on " Rose Saw-flies in the United States," records this 

 species as first discovered on his rose-bushes (Washington) in 1880 (Insect Life, vol. V,. 

 page 7), and it is also several years since I first bred the insect from larvte taken on a rose- 

 bush in Ottawa, although I cannot find a record of the exact date. I have since bred the 

 species on two or three occasions, and find that it is becoming more abundant. In 1891 

 I took a specimen at the High Falls on the Des Lievres about 50 miles from the city. 

 The species is apparently double-brooded here (in Washington three-brooded) as the flies 

 appear from May to July. The eggs are laid in the leaf-petioles and hatch in a few days. 

 The larva feeds on the under surface of the leaf, remaining concealed there, and at first 

 making small holes ; but these holes increase in size and number with the rapid growth 

 of the grub, and in a few days nothing will remain but the midrib and some of the stronger 

 laterals. The larva is greenish, with an almost orange head and with rows of small warts 

 from which rise rather stiff bristles or hairs f When fully grown a delicate thin cocoon, 

 with a more or less complete outer one, is spun upon the under side of the leaves or 

 branches, or in rubbish upon the ground. The pupal state of the first brood lasts about 

 a fortnight, but the second brood passes the winter in this foim. The flies are consider- 

 ably larger than those of M. rosce and have the legs and wings paler. 



The third species, which has been noticed here for the first time this year, is 

 E7r7phytus cindus, Linn., of which the larva may be distinguished as the curled Rose- 

 worm, from its position when at rest. This is also a well-known European species, which 

 received a new name {cinctipes) from Norton in 1867. This species was first reported as 

 a rose-pest in America by Mr. John G. Jack, who found it very injurious in Boston and 

 Cambridge in 1887 and following years. The eggs are laid singly on the under side of 

 the leaf, but there may be several on a single leaf. The larva? are smooth cylindrical 

 worms, somewhat stouter toward the head, (which is tawny with a black patch on vertex) 

 and are greenish or yellowish-green above and whitish below. They feed on the edges of 

 the leaves until these are consumed, and when at rest are coiled spirally beneath a leaf, or 

 on the stripped stems. When fully grown they are said to generally pupate in the rose- 

 branches, or in rotten wood or pith. Those that I bred this summer, however, buried in 

 the ground in preference to using the pieces of corn pith which I had provided for them. 

 There are probably two or more broods of this species here, as in the United States and 



*Cameion states of the European insects that, " The eggs are laid in the midrib in May," and that; 

 " The small oval cocoons are spun in the earth." 



tit may be mentioned here that the descrii)tion given by Dr. Riley does not quite agree with that given' 

 by Cameron of British larvw. 



