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X. The Anatomy and Development of certain Chalcididse and Ichneumonidse. By 



George Newport, Esq., F.B.S., F.L.S. 8fc. 



PART III. ICHNEUMONTD^ (continued). 



Read June 5, 1849. 



Ichneumon Atropos, Curtis. 



oEVERAL years ago, chiefly in the year 1829, 1 obtained many specimens of Ichneumon 



Atropos (fig. 1. Tab. IX.), hoth 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 f, states it to have been bred by Miss Giraud at Eaversham, from the larva olAche- 



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 Ihe hatching of the 



egg after deposition, will bring us to the commencement of the last stage of the caterpillar, 



when its tegument is soft and pierced with least difiiculty. 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 Sty lops, 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 pupae of Sphinx ligustri during the 

 past summer, 1852. 



t British Entomology, vol. v. p. 234. 

 VOL. XXI. N 



