The Moths of the British Isles Volume Ii Part 10

2 Pl. 25.

1. HERALD: _caterpillar_.

2. SMALL PURPLE-BARRED: _caterpillar_.

3. ROSY-MARBLED: _caterpillar_.

{65}

The caterpillar is green, dotted with white; a dark line along the back and a white one along the sides. In the early stage it is black or sooty brown, and hides itself among the spun together flower buds, or in a turned down tender leaf. It feeds in May and June, occasionally found in late April, after hibernation, and a second generation sometimes occurs in July and August. Monkshood (_Aconitum_) and larkspur (_Delphinium_) are the usual food plants, and it is curious to note that whilst some observers state that larkspur alone is eaten, others say that monkshood is the only food.

The moth flies in June and July, and sometimes there is an emergence in August and September. It visits the blossoms of various garden plants, and is also attracted by light.

The caterpillar, represented on Plate 27, Fig. 1, was found with others on larkspur in Mr. Herbert Smith's garden at Wallington, Surrey. The coc.o.o.n and chrysalis is from a photo by Mr. H. Main. Another photo by Mr. Main shows the young caterpillar constructing its retreat.

According to Duponchel this species occurred in Normandy, Central and Northern Europe, as far back as 1829. A much paler form inclining to silvery, var. _esmeralda_, Oberthur, is found in Ussuri, North China, and other parts of East Asia.

THE BURNISHED BRa.s.s (_Plusia chrysitis_).

Two forms of this metallic-looking species are represented (Plate 22); 5 is typical and 6 shows the ab. _juncta_, Tutt. Between these are various intermediate stages leading to the complete division of the central band.

The broken central band is a character of var. _nadeja_, Oberthur, from Amurland and {66} j.a.pan, but that form has also a more or less complete series of ochreous-brown dots on the outer area. The metallic colour is sometimes greenish in all forms.

The caterpillar is pale green, with a darker green line along the middle of the back, bordered on each side by an irregular white line; an oblique white streak on the sides of each ring from 4-11; a stripe low down along the sides is white; head, yellowish tinged. It feeds on stinging nettle, probably on other plants, and after hibernation attains full growth about May. In favourable seasons caterpillars also occur in July and August. The moth is out in June, July, and August, less frequently in September, and may be found flying along the sides of hedges and ditches, especially where flowering weeds are plentiful, throughout the British Isles; so far, however, it has not been recorded from the Hebrides, Orkneys, or Shetlands.

THE SCARCE BURNISHED BRa.s.s (_Plusia chryson_).

The more or less square golden (sometimes green-tinged) patch on the velvety purplish brown fore wings, distinguish this species (Plate 24, Fig.

1) from any other British _Plusia_.

The caterpillar is green, with a darker line along the middle of the back, and a fine white line on each side of it; there is a dark green stripe low down along the sides, edged below with white, and oblique white lines run from it to the central line on rings 3-11. It feeds on hemp-agrimony (_Eupatorium cannabinum_), hibernates when small, and completes its growth in May or early June.

The moth is out in July and August, and is said to be occasionally seen, on sunny days, flying about, or resting on, the flowers of the hemp-agrimony and other plants. Night, however, is its more usual time of activity, and it may also be found at the blossoms of the larval food plant, and at those of honeysuckle, etc. {67}

The species has been found, chiefly in the past in most of the southern counties of England from Kent (Deal district) to Cornwall, also in Gloucesters.h.i.+re, and in South Wales. Chippenham fen in Cambridges.h.i.+re is the most noted locality for it in the present day, and it has been found in Norfolk and Suffolk. There is even a record of a specimen having been beaten out of honeysuckle near Preston, Lancs., but this happened nearly forty years ago.

The range abroad extends to Amurland and j.a.pan.

THE GOLD SPANGLE (_Plusia bractea_).

The purplish brown fore wings of this moth have a bright solid-looking golden mark on the upper edge of a velvety, deep brown patch. This metallic "spangle" varies a little in size and in shape, but not to any noteworthy extent (Plate 24, Fig. 2).

The caterpillar is bright green, dotted with white, above, and dull darker green below; there is a fine dark green line along the middle of the back, some indistinct and irregular white lines followed by a whitish stripe lower down, along the sides. It seems to feed upon a variety of low-growing plants, among which are groundsel, dandelion, white dead-nettle (_Lamium alb.u.m_), and stinging nettle, also on honeysuckle, from August to May. In a state of nature, it hibernates when small, and becomes full grown in May or early June, but when reared from the egg it can be induced, by keeping it in a warm place, to continue feeding, grow up quickly, pupate, and a.s.sume the winged state in the late autumn. Under such artificial conditions it is said to eat lettuce and plantain.

Normally, the moth is out in June and July, and has been met with in August. Like all members of this group it is partial to flowers, and has been frequently taken at those of the honeysuckle, although all sorts of blossoms, down to the lowly _Viola cornuta_, have attraction for it. {68}

The species is more especially a denizen of Ireland and Scotland, but it occurs in most of the northern counties of England, and has been recorded from Worcesters.h.i.+re and Herefords.h.i.+re; also from Carmarthens.h.i.+re in South Wales.

Abroad, its range extends to Central Asia; and in Amurland and j.a.pan it is represented by P. excelsa, Kretschmar.

THE GOLD SPOT (_Plusia festucae_).

In this species (Plate 24, Figs. 3 and 4) the fore wings are golden brown, clouded with purplish brown; sometimes the purplish brown is confined almost entirely to the broad area. Besides the large central metallic marks, there are more or less conspicuous patches of metallic colour at the base of the costa, on the middle of the inner margin, and towards the tips of the wings. Usually the central spots are clearly apart, but I have one example from Bishop Auckland, Durham, in which they are only separated one from the other by a slender brown line.

The caterpillar is green, with a white-edged dark-green line along the middle of the back, and some slender yellowish lines on each side of it; a whitish or yellow tinged stripe low down along the sides; head, tinged with brown.

It feeds on sedge, coa.r.s.e gra.s.ses, bur-reed (_Sparganium ramosum_), and yellow-flag (_Iris pseudacorus_); also said by Collins to eat water plantain (_Alisma plantago_): April to June, and in some localities and seasons, again in July and August. The black chrysalis is enclosed in a rather long greyish coc.o.o.n, spun up on the undersides of the leaves of sedge or reed; usually placed towards the tip of the leaf, which droops over and so hides it.

The moth is out in June and July, and in some years there seems to be an emergence in August and September; this has been more particularly noted in Ches.h.i.+re, where Arkle has had moths emerge in June, July, August, and September. A second flight has been noted in Ireland by Kane and others; and late examples have also been recorded from Scotland.

[Ill.u.s.tration]

2 Pl. 26.

1, 2. SILVER Y.

3. NI MOTH.

4, 5. SCARCE SILVER Y.

6, 7. MOTHER s.h.i.+PTON.

8, 9. BURNET COMPANION.

[Ill.u.s.tration]

2 Pl. 27.

1, 1a, 1b. GOLDEN PLUSIA: _caterpillars and chrysalis_.

2. DARK SPECTACLE: _caterpillar_.

{69} Although it has been recorded from some of the southern counties, it is most frequent in the eastern and northern parts of England, and in South Wales. Occurs throughout Scotland up to Moray; and in Ireland it is found in most localities, though not often common, except by the sea in Co.

Kerry, and in Connamara, Co. Galway.

Abroad, it extends to East Siberia, Amurland, and j.a.pan.

THE PLAIN GOLDEN Y (_Plusia iota_).

In typical specimens the metallic mark is V-shaped, with a dot below and a little to one side (Plate 24, Fig. 8). In ab. _percontationis_, Treit.

(Fig. 7), these spots are united and form a Y-like mark. Sometimes the spot is absent and the V-mark much reduced, and more rarely the V also disappears (ab. _inscripta_, Esp.).

The larva is yellowish green, white dotted, with a white-edged darker line along the middle of the back; a band composed of whitish irregular lines runs along the sides, and a thin yellow line along the area of the spiracles. It hatches from the egg in the late summer, hibernates when quite small, and feeds up in the spring. The food plants comprise the dead nettles (_Lamium_), woundwort (_Stachys_), mint, stinging nettle, honeysuckle, hawthorn, etc. There is a record of sixteen larvae which hibernated among dead leaves of _Lamium alb.u.m_, resumed feeding on February 18, spun up April 23-25, and produced moths May 27-June 4. Usually the moth is on the wing in June and July.

The species seems to be pretty widely distributed throughout the British Isles to the Orkneys; it was not known to occur in the Hebrides until 1901, when McArthur obtained it in the Isle of Lewis. {70}

THE BEAUTIFUL GOLDEN Y (_Plusia pulchrina_).

This species (Plate 24, Figs. 5 and 6) so closely resembles the last that it has been considered a variety thereof; there is no question, however, that it is quite distinct. The fore wings in both species are somewhat similar in general tints, but the following points of difference distinguish _pulchrina_--the darker colour is less evenly displayed, and gives the wings a more mottled or marbled appearance; the cross lines, especially those on the basal area, are almost invariably golden edged; the second cross line is more acutely bent inwards above the inner margin, the reniform has a more or less complete golden outline, and it is placed in a dark cloud; the golden V-mark and dot below are generally thicker. As a rule, the fringes of all the wings are more distinctly chequered, but this feature cannot be relied on alone in separating one species from the other.

In ab. _percontatrix_, Aurivillius (= _juncta_, Tutt), the golden V and dot are united and so form a Y-mark (Fig. 5).

The caterpillar is green with a broad central white stripe and several finer white lines along the back; a yellowish-tinted white stripe low down along the sides; head s.h.i.+ning, marked with black on each side of the mouth.

This caterpillar has the bristles rather more in evidence than they are in the larva of _P. iota_. It feeds on various low-growing plants, such as the dead nettles, groundsel, etc., also on honeysuckle and bilberry.

The moth occurs in June and July, and is found more or less frequently all over the British Isles to Orkney, but in England is more plentiful from the Midlands northwards than in the southern counties.

The range abroad extends to Amurland.

THE NI MOTH (_Plusia ni_).

The present species (Plate 26, Fig. 3) bears a strong resemblance to a small pale specimen of _P. gamma_; but, as {71} will be noted, the silvery central Y-mark is differently formed. Here it is made up of a curve somewhat like the letter U, and an oval or round spot, the latter very close to and sometimes, as in the example figured, united with the former.