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X. The Anatomy and Development of certain Chaleidide and Ichneumonide. By 
GEORGE Newrort, Esq., F.R.S., F.L.S. $c. 
PART III. ICHNEUMONID4 (continued). 
Read June 5, 1849. 
ICHNEUMON ATROPOs, Curtis. 
SEVERAL years ago, chiefly in the year 1829, I obtained many specimens of Ichneumon 
Atropos (fig. 1. Tas. IX.), both in the larva and perfect states, in the neighbourhood of 
Canterbury, but I have not yet met with it in any other locality, nor since the year 1834*. 
Mr. Curtis, to whom we are indebted for the description, and an admirable figure of the 
species t, states it to have been bred by Miss Giraud at Faversham, from the larva of Ache- 
rontia Atropos; that the perfect insect, from which his drawing was made, was taken at 
Rochester by Professor Henslow; and that another specimen had been taken at Darent 
Wood by Mr. Davis, so that the insect appears to be a truly Kentish species. It was by 
no means uncommon in the neighbourhood of young ash plantations, at Canterbury, in 
the month of July, at the period I have referred to, when I took it on the wing; and I 
have several times reared it from the pupa of Sphinx ligustri, and very frequently have 
found the larva within the body of the larva of this Sphinx. It seems in fact to be 
a parasite common to this Sphinx; much more so perhaps than to Acherontia Atropos. 
Mr. Curtis, when describing the species, suggests that the true Ichneumons “ prefer 
naked caterpillars, and probably puncture them after they have descended into the earth, 
but before they have changed into chrysalids." But this is not the habit of Ichneumon 
Atropos, as I have often found the Ichneumon-larva (fig. 2 a, b, c) within the body of the 
Sphinx caterpillar several days before this had acquired its full growth, or had ceased to 
feed, and consequently long before it would have entered the earth to change to a pupa. 
I suspect that the egg of the Ichneumon is deposited quickly after the caterpillar has 
changed its skin, and has entered its last period of growth; since, at about the middle of 
that period, I have found the parasite within it more than a quarter of an inch in length ; 
and consequently, it must then be at least two or three days old. This length of time, 
added to a similar period, which we may suppose to be necessary for the hatching of the 
ege after deposition, will bring us to the commencement of the last stage of the caterpillar, 
when its tegument is soft and pierced with least difficulty. I am not aware whether the 
Ichneumon-egg is deposited on the surface of the skin through which the larva eats its 
way into the body, when hatched, like the larva of Séylops, or whether, as seems to be most 
probable, the egg is plunged at once into the caterpillar. The latter opinion seems to be 
* Since this paper was read, I have obtained two specimens of the imago from pupæ of Sphinx ligustri during the 
past summer, 1852. 
T British Entomology, vol. v. p. 234. 
VOL. XXI. N 
