Early Thorn (Selenia bilunaria).
The sexes of the spring or typical form are depicted on Plate [112], Figs. 1 ♂, 2 ♀, and the paler summer form var. juliaria (July Thorn), Haworth, is represented by Fig. 3. The underside is shown in Mr. H. Main's photo of the moth in its natural resting attitude.
The caterpillar is orange or reddish brown, sometimes inclining to purplish; there are pairs of reddish raised points on the back of rings 7 and 8; as will be seen from the accompanying illustration, which is from a photograph by Mr. Main, the creature, when resting, is very like a twig. It feeds on birch, alder, sallow, hawthorn, sloe, etc., in May and June, and again in August and September. The moth is out in April and
early May. In 1905, a male occurred at Carnforth, Lancs., on June 8; the second generation appears in July and August. A third has been obtained in captivity, and the moths of this brood are similar to those of the second. It has happened that the emergence of some moths of the second, or summer, form has been delayed until the following February, but these remained true to their race and did not assume the spring form.
Fig. 7. Early Thorn at rest. |
Fig. 8. Caterpillar of Early Thorn. |
| (Photos by H. Main.) | |
Generally distributed throughout England and Wales, and often abundant, especially in the south. In Scotland, Renton states that it is common in Roxburghshire, but there is only one brood; the range extends to Sutherlandshire. Widely spread in Ireland and plentiful in some parts.
Lunar Thorn (Selenia lunaria).
A female of this species is shown on Plate [112], Fig. 4; the male is usually more clouded with reddish. A second generation is sometimes raised in captivity, and the males of this brood (var. delunaria, Hübner) are somewhat paler, whilst the females incline to a yellowish tint. In Scotch specimens, the reddish markings are tinged with purple; and ab. sublunaria, Stephens, from Derbyshire, has the coloration very similar to that of the spring form of S. tetralunaria.
The caterpillar is figured on Plate [113], Fig. 2. The ground colour is usually some shade of brown, ranging from greyish or greenish to reddish, variegated with darker or paler clouds, and with traces of pale lines on the back. It occurs in the open from July to September, but may be reared both earlier and later in confinement. It feeds on sloe, plum, oak, birch, etc. The moth, in May and June, is sometimes seen on hedges or on the plants growing below; or it may be jarred from the branches of trees, when it is more apt to fall to the ground than to fly. Like others of this group it is fond of light, and is frequently attracted thereto at night. The species is rarely plentiful, and always more or less local, but it is widely distributed over the British Isles to the Orkneys.