OF CERTAIN CHALCIDIDZ AND ICHNEUMONIDZÆ. 69 
Of fifteen specimens allowed to complete their changes, there were only two males, with 
thirteen females. The remaining specimens I had preserved in their larva and nymph 
states for dissection. This small number of males coincides with the small number of 
this sex in other bee-parasites; but the deficiency in numbers is fully compensated for by 
the activity of the individuals. | 
The fewness of the males, and their great activity, lead me to believe that the females are 
impregnated, not before, but shortly after they have left the cell, and in the hot sunshine. 
Like the Chrysidide, these insects are active only in strong light. Both sexes of my speci- 
mens always became dull and motionless when removed from the light; but when exposed 
to the sun they immediately resumed their activity. They seem to live but a short period in 
the imago state. The males died within a few days, and the females in about a fortnight. 
I have proposed for this species the name of nitidus *, from its elegant and glistening 
appearance. It may be described as follows: | 
MONODONTOMERUS NITIDUS. 
Male.—Head and thorax brilliant shagreen, with fine short hairs: head broader than the thorax, face 
bluish; labrum emarginated; eyes and ocelli large, dark brown; antennæ 11-jointed, basal joint 
` coppery. Prothorax compressed and slightly excavated at the sides. Metathorax and scutellum 
large. Abdomen green bronze, hairy, petiolated, very much compressed at its base, and keeled on 
the ventral surface; first and second pairs of thighs green; third pair large, copper-coloured; tibiæ 
and tarsi fuscous, very hairy. Wings hyaline, hairy, with black costal spot. Length two lines and 
a half. 
Female (fig. 12).—Head and thorax brilliant shagreen, hairy: head large; face blue, punctured; eyes and 
ocelli large, brown; antennæ pubescent, 11-jointed, with the basal joint coppery, as in the male. 
Thorax compressed laterally. Scutellum very large. Thighs green, shining. Tibiæ and tarsi hairy, 
fuscous, with an acute spine at the articulation of the tibiæ. Abdomen coppery, polished, with a few 
white hairs, subsessile, compressed at its sides, and strongly keeled; ovipositor exserted, longer than 
the abdomen, and very acute. Wings dusky iridescent, hairy, and with dark marginal spot. Length 
of body two lines f. 
From the length of the ovipositor in this insect, we may conclude that the female does 
not enter the bees' nest to deposit her eggs; but that she perforates the cell and conveys 
them into it, after the cell is closed, and probably after the young bee is hatched. Every 
part of the anatomy of this insect, as of the preceding, and of every other species when 
attentively considered, will thus be found to exemplify its general economy, and to indi- 
cate how closely the one is connected with the other, —how intimately associated is ‚the 
instinct of a living being with special conformations of its organism. Some other families 
of Hymenopterous parasites are marked instances of the unfolding of peculiar instincts 
subsequent to the development of particular structures. Amongst these we may notice 
two of the true Ichneumonidae, Paniscus virgatus and Ichneumon Atropos. 
Entomological Society, on the 3rd of July, 1848, and 
` * This proposed for the insect at a Meeting of the 
ae DA x. then mentioned. See Proceedings, Ent. Soc. Trans. 
the discovery of the larva in the nests of Anthophora retusa was 
vol. v. part 5. p. xlii. 1848. ~ : 
© 4 Mr. Walker has recently re-described this species as “ Monodontomerus Anthophore, Newp." See Ann. and 
Mag. of Nat. Hist. vol. ix. No. 49. Jan. 1852, p. 43. 
