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Darwin Correspondence Project

From H. T. Stainton   29 February 1868

Mountsfield, | Lewisham. | S.E.

February 29th 1868

My dear Mr Darwin,

I now reply seriatim to the points noted in your letter of the 18th inst.1

1. The Males of the Emperor & Brimstone butterflies are visibly more numerous than the females—but with me that is no evidence that their numbers are really greater—2 Mr Doubleday says of the Emperor moth (Saturnia carpini or Pavonia-Minor) he breeds more males than females, but I doubt whether you would find that the general experience.3

2. With reference to Pamphila Actaeon I can give no information.4

3. In many genera of moths the males have whiter underwings that the females— this renders them much more conspicuous in the evening dusk— The common Agrotis exclamationis is a good instance of this.5

With reference to the Oenistis quadra I have no information.6

4. I cannot call to mind that I ever noticed an instance of courting in the Fritillaries or Vanessæ.7

I have seen it in the white butterflies but then the female was sitting down calling the male— whether there had been any preliminary stages I cannot say.

5. I am not aware of any moths in which the underside is more conspicuous than the upper side (of which in Butterflies we have such a striking instance in the Green Hair Streak Thecla Rubi)— the underside of the Red Underwing is very conspicuous but not more so than the upper side.8

6. With a few exceptions all the most gaily coloured moths are diurnal in their habits.

7. Generally speaking there are no strongly marked sexual differences in the Tineina   in a few cases we have apterous females, then females with abbreviated wings as in Chimabacche Fagella 9— the differences in colour & marking are most conspicuous in the genus Elachista—but the long-horned moths of the genera Adela & Nemotois 10 are the most singularly different—whilst the differences are very slight in the wings— the antennae, eyes, palpi & clothing of the head are quite different.

Towards the end of April & beginning of May a little whitish moth Elachista rufocinerea flies along the hedge-bottoms towards dusk— these are the males on search for the female. By looking carefully on the blades of grass a female may be seen at rest— she is at once recognised by her whiter & rather more pointed wings— not unfrequently the female will be found not at rest, but sitting with her wings expanded & her body raised, fluttering her wings—& this may be noticed when there is no male near.— the males flying along the hedge-bottom come to such a female & congregate round her perhaps as many as 12 or 20— one pairs with the female & the rest fly onwards in search of other females.11

In reference to your letter of Feby 21 I cannot say whether the artificial condition of life of a caged caterpillar in any way affects the sex—but I strongly incline to the belief that if collected in the pupa state the majority would still be females.12

I enclose you copies of some correspondence I had just had with Mr Doubleday & Mr Hellins on this subject, which I thought would interest you.13

Many years ago I had much diversion with the Scotch form of Lasiocampa Quercus & almost any number of males might be caught by taking a bred female on to the moors they frequented.—14 but yet I never knew the slightest difficulty in breeding a female if 2 or 3 pupæ were obtained & as Mr Hellins well puts it if you had only one pupa it was far more likely to produce a female than a male.

You will find mention of the assembling propensities of the males Bombycidae in Westwood’s Introduction to the Modern Classification of Insects vol II p. 38415

I do not think that a male insect serves more than one female

I would in conclusion throw out the suggestion that you should call the attention of Entomologists to points (on which you want information) to be observed during the coming season.16


H. T. Stainton to Henry Doubleday, Esq. Epping

Feb. 25, 1868

Mr Darwin is at present collecting information as to the relative numbers of the sexes in insects.

I have told him that my experience as a breeder is directly opposed to my previous experience as an insect–collector, as in breeding I find the females predominate.

I should be glad if you would give me any details of your experience, especially where you have reared an entire brood of a species.

Even in the Bombycidae of which the males swarm round a female I fancy the bred females preponderate.

Pray excuse my troubling you with this query, but your experience in breeding Macros 18 has been so great & so long continued, that your observations will be most valuable.

Henry Doubleday to H. T. Stainton

Feb. 26, 1868

I received your welcome letter this morning & beg to assure you that I am always glad to give you any information that I can upon Entomological subjects.

I am decidedly of the opinion that the males of all insects are more numerous than the females, & I do not recollect a single instance among the MacroLepidoptera when I have reared whole broods, in which the females were more numerous than the males. —some years since I reared a large number of Selenia Ilustraria 19 from the eggs & I think two-thirds of them were males—it was the same with broods of Orgyia gonostigma, Saturnia Carpini &c.20

I have never reared whole broods of any of the MicroLepidoptera.

I think the males of Gonepteryx Rhamni 21 for instance, must be far more numerous than the females, as when they re-appear in the spring, none of the common White Butterflies are out & you certainly see a dozen males to one female.

I have seen many hundred male Miana fascinncula but not more than half a dozen females, two of which I took last May.

The females of Miana strigilis are common enough but not quite as abundant as the males.22

I shall have much pleasure in answering any more questions upon this subject.

H. T. Stainton to the Rev. J. Hellins, Chaplain’s House, County Recson,23 Exeter

Feb. 25, 1868

Mr Darwin is busy collecting information as to the relative numbers of the sexes in insects. Now my experience as a breeder of Micros is that the females preponderate—as you must have had considerable experience by this time in breeding Macros I should be glad to hear what you have found to be the case, more especially in those instances in which you have reared an entire brood.

If you have had sufficient experience of insect collection in the pupa state I should be glad to learn whether in those cases the females do not also preponderate.

Pray excuse the trouble I am giving you.

Rev. J. Hellins to H. T. Stainton

February 26, 1868

My impression is decidedly that as a rule I breed more female moths than males–a rule not without striking exceptions—still holding so generally good, that if I had one egg—one larva and one pupa—I should expect to breed a female moth; or if I had two or three—still I should not quite expect to get a male: i.e. trusting only to chance.

When I dug pupae I fear I didn’t keep account—but if you will give me ten days I will look up my note books & see what I can find out.

I understand that those who keep poultry expect more cocks than hens, & such people have been surprised to hear me say what I found in the case of my insects.

Also—my children have been keeping guinea–pigs for the last two years & certainly the “old mother” who was the foundation of their stock & has gone on having broods ever since, has produced more sons than daughters!

You know I don’t often rear large broods—because I don’t care for heaps of specimens, only to watch the transformations & six larvae are much more likely to thrive than sixty.

CD annotations

1.1 I now … 18th inst. 1.1] crossed pencil
3.1 2. With … Vanessæ. 6.2] crossed pencil
4.1 3. In … dusk— 4.2] ‘But differences not very conspicuous’ pencil
4.2 Agrotis exclamationis 4.3] ‘V’ added blue crayon
8.1 5. I … different 10.6] crossed pencil
11.7 the males flying … 20— 11.8] double scored red crayon; double scored blue crayon
12.1 In reference … interest you. 13.2] crossed pencil
16.1 I do not … call 17.1] crossed pencil
Top of letter: ‘No of sexes’ pencil
Enclosure, 4th letter
3.1 I … insects. 3.2] scored pencil
4.1 Also … daughters! 4.3] scored pencil
5.1 I don’t care … sixty. 5.3] double scored pencil; ‘so he wd probably collect larger caterpillars’ pencil


See letter to H. T. Stainton, 18 February [1868].
See letter to H. T. Stainton, 18 February [1868] and n. 2. See also letter from H. T. Stainton, 20 February 1868, in which Stainton claimed that accurate information on the proportion of the sexes could only be obtained from insects bred in captivity.
In Descent 1: 311, CD reported that Henry Doubleday and some other entomologists maintained that they had reared from the egg and caterpillar stages a larger proportion of males than females. The emperor moth is now Saturnia pavonia (family Saturniidae); it is mentioned in Descent 1: 311, 398.
See letter to H. T. Stainton, 18 February [1868] and n. 3.
CD cited Stainton’s remarks on Agrotis exclamationis (the heart and dart moth) in Descent 1: 398–9.
Oenistis quadra (the large footman) is now Lithosia quadra (the four-spotted footman). Stainton described the different coloration in the sexes in Stainton 1867, pp. 155–6.
See letter to H. T. Stainton, 18 February [1868] and nn. 5 and 6.
In Descent 1: 397, CD stated on Stainton’s authority that in moths the under surface of the wings was very rarely more brightly coloured than the upper side. Thecla rubi is now Callophrys rubi. The red underwing is Catocala nupta.
Chimabacche fagella (the March dagger) is now Diurnea fagella.
Nemotois is now Nemophora.
Stainton’s description of Elachista rufocinerea is given in Descent 1: 311.
See enclosure. Stainton refers to John Hellins.
Stainton refers to Westwood 1839–40.
Stainton announced CD’s interest in various aspects of sexual selection involving coloration at the 2 March 1868 meeting of the Entomological Society of London (see Transactions of the Entomological Society of London (1868): xiv).
The enclosure is a copy, in an unknown hand, of Stainton’s correspondence with Doubleday and Hellins.
Stainton refers to macrolepidoptera: those families of butterflies and moths whose members are large enough to be of interest to the majority of collectors (OED).
Probably Selenia illunaria (now S. dentaria), the early thorn moth (Fletcher 1979, p. 188).
The address is probably a copyist’s error: Hellins was chaplain of the Exeter county house of correction.
Orgyia gonostigma is the scarce vaporer moth. For Saturnia carpini, the emperor moth, see n. 3, above..
Gonepteryx rhamni, the brimstone butterfly.
Miana strigilis is now Oligia strigilis, the marbled minor.


Replies to CD on proportion of sexes in butterflies, coloration of moths, and courtship. Encloses copies of letters on these subjects between HTS, Henry Doubleday, and John Hellins.

Letter details

Letter no.
Henry Tibbats Stainton
Charles Robert Darwin
Sent from
Source of text
DAR 85: B52-3; DAR 86: A16;
Physical description
†, encl 4pp † & ACC 7pp

Please cite as

Darwin Correspondence Project, “Letter no. 5960,” accessed on 22 April 2019,

Also published in The Correspondence of Charles Darwin, vol. 16