99, THE ENTOMOLOGIST. 
had already taken its departure, they are necessarily crude, as 
it was the only example of its kind on which I had ever set eyes. 
For this and for their obvious artistic defects I shall make no 
further apology, as they are merely intended to convey the 
manner in which the insect accomplished its object. 
Sharp* figures (after Riley) the allied genus Thalessa in the 
act of oviposition, and states that in both these genera the 
ovipositor “‘is brought into use by being bent on itself over the 
back of the insect, so as to bring the tip vertically down on to 
the wood, through which it is then forced by a series of efforts ; 
the sheaths do not enter the wood.” 
It is evident that this description does not tally with the 
foregoing observations on Rhyssa. The insect figured by Sharp 
follows his statements in having its long ovipositor bent on itself, 
out ofits normal and approximately straight form, into an almost 
complete circle. From purely physical considerations, is it not 
a little difficult to understand how a non-muscular structure 
could be curved at will in this way? The possibility suggests 
itself to the present writer that the insect there figured, after 
having inserted its ovipositor in the manner described in this 
note for Rhyssa, may have pivoted its body through an angle of 
180° around the flexible fixed ovipositor, in its efforts to thrust 
the latter into an unusually resistant piece of wood. This might 
easily happen through the insect’s shifting its feet again and 
again to obtain a better purchase, and would explain the whole 
matter very simply, as the ovipositor in such a case would 
naturally assume the position figured. 
[There can be no doubt at all that Mr. Ramsay’s notes refer 
to R. persuasoria, L., which has an extremely wide distribution 
through Europe to Canada and the United States in the West, 
and the Himalayas in the Hast, since it is to the best of my 
knowledge the only species attacking pinetophagous larve. R. 
approximator, Fab., is said by Holmgren to attack Xyphydria 
prolongata, which feeds in oak; and there are several interesting 
accounts of the American species’ economy (Canad. Entom. xi. 
1879, p. 15, &c.) and Harrington has (I. c. xix. p. 206) put on 
record ‘“‘ The Nuptials of Thalessa.” Myr. Ramsay appears to 
take it for granted that these insects bore for themselves an egg- 
passage through the solid wood; but it is by no means proved 
that they do not oftener introduce them along the tunnel of the 
host larva (cf. Morl. Ichn. Brit. iii. p. 25, et Revision Ichn. Brit. 
Mus. u. p. 10).—Ciaupr Morty. | 
* ‘Cambridge Natural History, Insects,’ pt. i. p. 554, 1895. 
