HYMENOPTERA. — TENTHREDINID&. 99 
the large size and attractive appearance of these larva, they are occa- 
sionally attacked byichneumous parasites. I have obtained two distinct 
species of Ichneumonidz from one cocoon belonging to an individual 
of Trichiosoma lucorum. I have likewise obtained specimens of a 
species of Ichneumon, and others of one of the Pteromalide, from one 
cocoon.* ~ Mr. Woodward also noticed the occurrence of parasites in 
the cocoons of this insect, in the Mag. Nat. Hist. No.23. The 
cocoon ( fig. 69. 13., cut open to show the enclosed pupa) of this insect 
is as large as a small bird’s egg, and is attached to the branches of 
the white thorn, upon which it may be easily perceived in the winter, 
when the trees are destitute of leaves. In one which I observed 
the larva remained in that state through the winter, not assuming the 
pupa state till the end of April, and the insect appeared in the perfect 
state in about a fortnight. 
The larvee of the genus Hylotoma are distinguished by having the 
sides of the abdominal segments produced over the legs, and the base 
of the claws of the thoracic feet is furnished with a large fleshy tu- 
bercle. (Hartig, pl. 2. f.12.) The larve of H. Rose are ordinarily 
observed on the leaves of the rose, resting with the extremity of the 
body elevated, and often curved into the form of S. 
Some larvee belonging to this genus have twenty feet, namely, six 
thoracic and fourteen abdominal. Here belongs the insect which feeds 
upon the birch, figured in its different states by De Geer (Mem. t. i. 
p- 38. f. 32—35.), which has been given as Abia nitens, but which 
Hartig and Dahlbom properly regard as Hylotoma ustulata ; as well as 
a species which feeds on the rose, which Dahlbom gives as HZ. atrata 
Klug, but which St. Fargeau gives as H. ustulata; also figured by De 
Geer (tab. 39. f. 14—20.). 
The other larve in this genus have only eighteen legs; or, rather, 
the pair on the seventh abdominal segment are so small as to appear 
nearly obsolete. (Hartig, p. 76.) Of these species Rosel (Ins. Belust. 
vol. ii. Bomb Vesp. tab. 2.) and De Geer have figured H. Rosarum 
Klug, Hartig (Rose St. Farg.),.Dahlbom, Bouche (Naturgesch. 
p- 135., in his plate 39. f. 21--29.), which feeds on different species of 
roses; and H. enodis Linn., Dahlbom, and Hartig (H. atro-czrulea 
St. Fargeau), which feeds upon the sallow, is figured by De Geer 
(pl. 40. f. 1—6.). Réaumur has figured the history of two species of 
Rose Hylotome in his Mémoires (tom. v. pl. 14 and 15.). 
* The details of these obseryations will form the subject of a separate memoir. 
H Z 
