The larva is greenish or greyish, sometimes with a reddish tinge, with a light line down the back. The twelfth segment is humped, and there are dark V-shaped marks on the back of segments five to twelve inclusive. It is full grown in September, and burrows into the ground to undergo its change to the chrysalis, in which state it remains throughout the winter.
_The Rustic Shoulder-knot_ (_Apamea basilinea_)
The fore wings of this species are pale ochreous grey, with light brown markings; and there is a short dark streak in the middle of the base, from which feature the specific name (_Basilinea_) is derived. The hind wings are of a similar colour, but shading into a dark smoke colour at the hind margin.
[Ill.u.s.tration: FIG. 152.--THE RUSTIC SHOULDER KNOT.]
The caterpillars feed at first on the grains of wheat, on the ears of which the moth deposits the eggs in June. At harvest time they remain hidden among the husks, and are often threshed out in large numbers by the blows of the flail. The cold weather soon overtakes them, and they then spin a coc.o.o.n in which to pa.s.s the winter. On the approach of spring they come out again, and feed by night on various low plants, hiding themselves among the roots by day. In March they are full grown, and change to brown chrysalides beneath the surface of the ground.
The moth flies in June, and is one of the commonest and most destructive of our _Noctuae_.
_The Marbled Minor_ (_Miana strigilis_)
The next three genera (_Miana_, _Phothedes_, and _Celaena_) include seven small moths known as the "Minors." The commonest of them is the Marbled Minor, which is to be found in abundance everywhere during June and July.
[Ill.u.s.tration: FIG. 153.--THE MARBLED MINOR.]
This species is very variable, but the fore wings are usually dark brown, marbled with a lighter colour--white or grey. There is generally an irregular white or pale grey band crossing the wings parallel with the hind margin, and two white marks on the inner margin, halfway between this band and the base. There is also a deep black blotch across the middle of the wing.
The caterpillar is greyish or greenish with paler lines and black spiracles. It feeds on gra.s.ses in March and April, and changes to a chrysalis under the ground in May.
Family--CARADRINIDae
There are only ten British species in this family, two of which are rare; and most of the others are particularly dingy. The transverse lines so often seen on the fore wings of Noctuae are generally well marked. The larvae have short stiff bristles, and feed on low plants; they undergo their changes in an earthen coc.o.o.n under the ground.
_The Mottled Rustic_ (_Caradrina Morpheus_)
We select as our type of this family the Mottled Rustic--a common moth that may be procured from June to August. Its fore wings are brownish grey, with darker lines and spots; the hind wings are almost white, but darker at the tip.
[Ill.u.s.tration: FIG. 154.--THE MOTTLED RUSTIC.]
The caterpillar is brownish grey, with a row of triangular spots on each side of the back. It is very sluggish, spending the greater part of its existence among the roots of low plants. It feeds throughout the winter, except during severe weather, and is full grown in April. The food plants include teasels (_Dipsacus pilosus_ and _D. sylvestris_), hedge bedstraw (_Galium Mollugo_), orpine (_Sedum Telephium_), sallows (_Salix_), and various other plants.
The chrysalis may be dug out in May.
Family--NOCTUIDae
A glance at our list of British _Noctuae_ (Appendix I) will show that this family contains nearly fifty species and only three genera. It includes several very common moths that frequent our gardens and are to be met with during almost every summer evening ramble.
Most of the species are very dingy, but the half-dozen that comprise the genus _Triphaena_ are characterised by the bright colouring of the hind wings. The fore wings are narrow and more or less glossy, and overlap to a greater or less extent when the insects are at rest; and the hind wings are folded and completely hidden beneath them.
The larvae are rather thick and smooth, and generally of very dingy colours. They feed on low plants, often confining their ravages to the roots, and generally lie well concealed close to the ground or under the surface.
The pupae are brown, smooth, and shining, and are usually inclosed in earthen coc.o.o.ns.
We shall briefly notice a few members of each of the three genera.
_The Turnip Moth_ (_Agrotis Segetum_)
This is another of those destructive insects that attack vegetable and flower gardens, often doing so much damage to our crops as to become quite a nuisance to cultivators.
The moth is decidedly dingy. Its fore wings are brown, clouded with a darker tint. The hind wings are almost white, sometimes with a brown hind margin.
[Ill.u.s.tration: FIG. 155.--THE TURNIP MOTH.]
In June it lays its eggs on the stems of young plants, generally very close to the ground. As soon as the young caterpillars emerge they commence feeding on the lower parts of the stems, or burrowing deeply into the larger succulent roots. When the larvae have completed their work of destruction in this way, they change to brown chrysalides in the ground. Some undergo this change in October, and shortly after give rise to a second brood of moths; but most of them remain in the caterpillar state throughout the winter, and, contrary to the general rule with hybernating larvae, continue to feed almost throughout the winter months, and change to the chrysalis in the following May.
The caterpillar grows to a large size. It is of a greyish or greenish colour, with a paler line on the back, a light brown line on each side of this, black spots between these lines, and black spiracles.
_The Heart and Dart_ (_Agrotis Exclamationis_)
The destructive work of _Segetum_ is a.s.sisted by similar operations of the Heart and Dart, the larva of which feeds voraciously on the roots of several of our cultivated vegetables, though the present species does not entirely confine its ravages to the farmer"s crops, but attacks the roots of many low-growing herbs.
The fore wings of the moth are light brown, generally with a reddish tinge. The darker markings include a large and very distinct reniform spot, a less distinct orbicular, and a conspicuous longitudinal blackish streak near the base of the wing known as the _claviform_. Beyond the reniform a curved and zigzag dark line crosses the wing. The hind wings of the male are very pale, those of the female darker, with a whitish fringe.
[Ill.u.s.tration: FIG. 156.--THE HEART AND DART.]
The moth flies from June to August, and is common everywhere. The caterpillar feeds in the autumn, and reaches its full size in October; but it is said to feed at intervals throughout the winter. Its colour is dingy brown or grey, with paler lines on the sides. The spiracles are black, and there are black dots on the sides.
_The Garden Dart_ (_Agrotis nigricans_)
This is another dingy moth, whose general appearance is so unattractive that the tyro might be inclined to neglect it. But it must not be omitted from our selection on that score, for our main object here is to give the beginner an acquaintance with those species that are most likely to be captured in the earlier part of his career, and this moth is certainly one of those that may be described as "abundant everywhere."
[Ill.u.s.tration: FIG. 157.--THE GARDEN DART.]
Its fore wings are dull dark brown, often tinged with red, and clouded with black. The reniform spot is pale, the orbicular spot less distinct, and between the two there is generally a rhomboidal dark spot. There is also a short dark streak near the base of the wing, and a black spot before the orbicular. The hind wings are pale, but smoky towards the hind margin.
The caterpillar is brown and shining, with a fine pale line on the back, and a double white stripe below the spiracles. It is also dotted with black. It is exceedingly destructive, feeding on clovers (_Trifolium pratense_ and _T. repens_) and various low plants in May and June.
The moth flies from June to August.
_The Flame Shoulder_ (_Noctua plecta_)
As our example of the next genus we take the Flame Shoulder, a rather small moth, easily identified by the broad yellowish-white streak along the costa of the reddish-brown fore wings. The orbicular and reniform spots are margined with white, and a thin white streak runs from the base of the wing to the former. The hind wings are white. This moth flies in July, and is common throughout Great Britain.
[Ill.u.s.tration: FIG. 158.--THE FLAME SHOULDER.]
The caterpillar is reddish brown, with a slender line of white dots on the back, and a similar line on each side. The body is smooth and velvety, and is netted and dotted all over with dark brown. It feeds on the lady"s bedstraw (_Galium verum_), sweet woodruff (_Asperula odorata_), and many other low plants; and is full fed early in July.