February 17, 1890.
I have examined your caterpillars carefully, and I find that of the oak stem to correspond exactly with the larva of the Wood leopard moth, the Zeuzera æsculi. This is commonly found in (or at least it is usually sent me from) wood of fruit trees, but it attacks oak as well as forest trees of various kinds. Your specimen has also one of the characteristic habits of ejecting brown fluid from its mouth on disturbance. I think you have my “Manual,” and there you would find a figure of the moth and larva. Your specimen is rather full coloured, but they vary greatly in this respect.
Your other caterpillar is a Lepidopterous larva, but I cannot name it with certainty. It is quite possible that it is the larva of the “Hornet Clearwing,” the Trochilium (= Sesia) bembeciforme, but I have never seen a specimen, although the attack is said to be common, especially to Salix caprea. The attack is stated to be mostly in the lower part of the stem. I think that you very likely have Loudon’s “Arboretum” in your library, and if so you would find some good notes and fair figures of the hornet-like moth and its larva and pupa in situ in the wood at pp. 1481 and 1482, vol. iii. The larva is nearly dead now, so that the form is altered, but I do not see any reason against it being this kind; still I cannot say it is.
I have a very curious report of much damage attributed to Puss moth caterpillars at a locality in Lincolnshire, and am waiting with much interest for specimens to see what the cause can be. I rather expect it will be rabbits!
Yours very truly,
Eleanor A. Ormerod.
Male and caterpillar (life size).
FIG. 3.—PUSS MOTH, DICRANURA VINULA, LINN.
[The following notes by Mr. Robert Service[[46]] are explanatory of subjoined correspondence.
“The ‘Hill-Grub’ (the caterpillar of the Antler moth, Charæas graminis). Sheep-farmers are threatened with another plague. The ‘hill-grub’ has often done considerable damage to the upland grass-lands, notably in the years from 1830 to 1835. Just now complaints are rife from farms in many parts of the wide districts ravaged by the Voles[[47]] (in 1891-92-93). As usual the farmers look on these ‘hill-grubs’ as very sudden arrivals, but this is not the case, for last autumn the moths which these larvæ produce were in extraordinary swarms, and far in advance of their normal numbers. I remember noting at the end of last September when coming down from the neighbourhood of Loch Dungeon one evening in the twilight, how unusually abundant the Antler moths were flying. The evening was mild and very moist, and just as we got on to the level ground at the outside of a moss of perhaps six acres in extent, we found Antler moths flying in countless myriads in every direction. The time was 6.40, and there was still enough of the gloaming left to see the moths quite distinctly on every side, flying just below the level of the grass-seed heads.