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Insects at Home: Being a Popular Account of British Insects, Their Structure, Habits, and Transformations

PDF document782 original pagesPublished 1 January 1876
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The odom’ which these creatm-es give out is equally powerful and endm-ing, and to many persons is peculiarly hateful. Whether from use or not I cannot say, but I do not find it nearly so offensive as the odour of many other insects, such as the Dyticus beetle and the Lace-wing fly. The odour permeates the whole of the tunnels, and for years after they have been deserted the scent is sufficiently strong to denote the inhabitant.

hen the larva is full-fed it forms a cocoon made of fragments of gnawed wood and silk. The cocoon is very tough, and will withstand much rough handling. These cocoons are oval, similar in shape at both ends, flexible, and yellow in colour, and are very strongly scented with the odour of the insect which made them. There is considerable variety in the size of the cocoons, and some are barely half as large as others.

The small cocoons seem never to produce Moths, but are infested by an ichneumon-fly, which, fortunately for us, preys on the Goat Moth caterpillar. Not that the large cocoons are free from this parasite, for, as every one knows who has bred them, the large cocoons frequently disappoint the collector, and produce ichneumons instead of Moths. It is a curious fact that the ichneumon itself (^Lampronota setosa) possesses an odour similar to that of the larva in which it lays its eggs.

In the ‘Entomologist’ for August 1868, Miss E. Newman mentions that she possesses a Goat Moth cocoon which was made with earth instead of wood-chips, and was discovered in April, in the middle of an arable field. After being removed from the cocoon and placed in a breeding-cage, the larva again burrowed into the earth, and emerged at the end of June, perfect in every respect, but rather smaller than the usual size.

After the larva has lain in its cocoon for some time, it discharges from its mouth a fluid which is contained in two large sacs within the body, and softens the silk so that it can be easily broken. It then throws off the caterpillar skin and becomes a chrysalis, which is at first white and soft, but afterwards hard and brown. The edges of the segments are furnished with little points directed backwards, and by alternately stretching and contracting the abdomen, the pupa forces itself along its larval tunnel until it comes to the end. Just before the final transformation the pupa renews its efforts, and fairly pushes itself through the thin shell of bark that has been allowed to remain by the larva.

It still continues bo push its way on until it has forced itself through the opening, as far as the base of the abdomen. After a while the jmpal skin splits, and the Moth emerges slowly, climbing up the bark of the tree, and there clinging while it shakes out its wings. The empty pupa skin remains at the entrance of the tunnel, and towards the middle or end of summer, according to the season, plenty of these empty shells may be found projecting from trees that are infested with the Goat Moth larva. The Moth itself can generally be captured upon the bark of the tree in which it has passed its pupal state.

The willow is the tree that is usually infested by this insect, and vast damage is often done by it. On the Kentish marshes near my house are numbers of willow-trees, or rather the

remains of them, -which have owed their death to the Groat 3Ioth larva, and from them I have ]3rocured larvae and cocoons in plenty. Other trees, however, are attacked by this destructive insect, especially the elm, and Mr. Newman is of opinion that those trees which are apparently killed by the Scolytus (which has been described on page 186) have received their death-blow from the Groat Moth, and have only been attacked by the Scolytus when dying.

The Moth is a very troublesome one in a cabinet, as it is very liable to the two chief pests of the cabinet, namely, ‘ grease ’ and mites. I have known one of these Moths to be completely hollowed by the mites, and to show little signs of injury except the brown powder scattered under the affected insect. As soon as the Moth was taken up its body broke in two, and at least two teaspoonfuls of powder and mites were discharged over the other insects. Consequently it will be found advisable to stuff this Moth, and to put a drop or two of benzole into the cavity.

For further information on this insect, and a full account of its ravages, I refer to an admirable monograph by Mr. Newman in the ‘Entomologist’ of November 1869.

On Woodcut XLIV. (page 418) and Fig. 1 is seen a common and very pretty Moth belonging to the family Zygsenidge. The insects belonging to this family may be distinguished by their very brilliant and boldly contrasted colours, their habit of flying by day, the stout and hairy caterpillar, and the cocoon fastened in an upright position against the stems of p-asses. Only one genus inhabits England. The Moth which is given in the^ illustration is called scientifically Zygoena or Anthroceva filipendulce, and is popularly known as the Sixspotted Buenet. There are foiu species of Burnet Moth, three of which are so much alike that none but a practised entomologist can distinguish them, especially as the spots, from the number of which they derive their popular name, are almost pmcisely similar. This very beautiful insect has the upper wings of the deepest possible green, so deep indeed as to appear black unless the light be properly thrown upon it. The bwer wings are rich crimson, edged with black. The peculiar form of the antennm is so well shown in the illusf ration as to need no description. E F

The caterpillar, which is drawn at Fig. b, feeds on the Bird’s-foot trefoil {THfolium ornithopod/ioides) or the Common Deepwort {Spircea filipendula), from the latter of which the insect derives its specific name. The colour is yellow, with a slight brownish tinge, and it is diversified by a double row of black spots. When the larva is full-fed it climbs up a grass stem, and there spins a very curious cocoon, shaped exactly like a spindle, or, to speak more familiarly, like the wooden ‘ cats ’ that boys are apt to make in more profusion than is agreeable to adult pedestrians. These cocoons are pale straw-colour, rather tough, and very firmly fixed to the grass. The cocoon is shown at Fig. c. The perfect insect makes its appearance at the beginning of summer, and always flies in the hottest weather, so that the sunbeams play gloriously upon its splendidly coloured wings and body. Cold seems to paralyse the insect, and though on a hot calm day the Moths may be flying in hundreds over the field, a change of wind, bringing with it a blast of cold air, will send them all under cover, so that, though the field be actually studded with their cocoons, not a Moth will be seen.

The insect does not appear to travel far, but, like many others, to restrict itself to certain favoured localities. There were one or two fields near Oxford, which absolutely swarmed with these beautiful Moths, while at the distance of half a mile not a Burnet Moth was in sight. Owing to the great similarity of the different species, the entomologist who wishes to make a good collection must catch pretty well every Burnet Moth that he sees. With the exception of the Transparent Burnet {Zygcena Minos) — which I believe is an Irish, and not an English insect — it is absolutely impossible to distinguish one species from the other on the wing, and much care is required to separate them even when they are safely in the collecting box. I well remember, when beginning my practical researches into entomology, how puzzled I was with the difierent species of Burnet Moth, and how difiicult it was to believe that they really were difierent species, and not merely varieties of one species.

Passing of necessity over many Moths, we come to an insect which is both pretty and interesting. This is the Cinnabar

Moth {Calllmorpha Jacobece), which is rejoreseiiied on Woodcut XLA'I. Jhg. 1. It is an example of the family Euchelidse, in wliich the antennae are slender and without any fringe. The caterpillar spins a slight web, in which its hairs are scattered, and the pupa is small. The name Euchelidae is formed from two Grreek words, signifying Beautiful Caterpillar, and is given to the genus because the larvae are all very beautifully coloured.

To me this is one of the most familiar British Moths, being

  1. Gastropacha qnercifolia.

  2. Calliinol'pha Jacobe®, 2. Deiopeia pulcbella. c. Gastropacha, ct* Callimorpha, larva. 6. Deiopeia, larva. larva.

one of those that attracted me most as a child. At Oxford it is one of the most plentiful of insects, flying about so abundantly in the gardens that I always had— and still retain— a childish notion that it was the blossom of a scarlet-runner gifted with the power of flight. Common as it is in some places, it really is scarce m others. For example, F F so 2 practised an entomologist^as

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Illustration

tlio Eev. J. G reene states that he has only taken one specimen ' ‘

of the Cinnabar Moth in England, though he did find the ‘

pupa. Ihis part of Kent seems to be objectionable to the ‘

Cinnabar Moth, though the ragwort (Senecio Jacobea), on which it feeds, grows profusely in the neighbourhood. In and near

Oxford there is scarcely a plant of ragwort on which the pretty ‘

caterpillar, with its orange body and black rings, may not be found, 01 which has not some of tlie shining brown pupa3 near its roots. ^ This larva is shown at Fig. a. It has a habit of coiling itself into a ring when alarmed, and falling to the ground. ;

The colouring of the Cinnabar Moth is very bold, and is easily described. The upper wing-s are very deep olive-brown, looking' almost black by the contrast with the brilliant crimson stripe near the costal margin, and the two crimson spots near the hind margin. The lower wings are wholly crimson, slightly paler than that on the ujiper wings, and are edged with a narrow border of olive-brown. It is remarkable that the upper and under surfaces of this insect are exactly alike, except that i the under surface is slightly paler than the upper. The popular | name of Cinnabar Moth is given to the insect on account of the cinnabar-crimson colour of its wings.

On Woodcut XLVI. Fig. 2 is drawn a very pretty and very scarce Moth, called, from its colouring, the Crimson Speckled {Deiopeia pulchella). The upper wings of this moth are white, and they are covered with a number of square spots, seeming at first sight to be scattered promiscuously over the wings, but I having a tolerably regular arrangement. These spots are ; scarlet and black, and are set in transverse rows, the black and scarlet running alternately. The lower wings are white, witli a slight clouding of black towards the margin. The pretty i caterpillar is leaden blue, with a white streak along the back, and a row of scarlet spots along each side. ;

This is one of the rarest of genuine British Moths, and, if any ' ; of my readers should be requested to purchase a ‘ warranted British Crimson Speckled,’ they may be quite certain that the vendor is a conscious impostor, inasmuch as so valuable a prize r would not be hawked about for sale.

Mr. Newman’s quaint and true remarks respecting certain butterflies will apply to this and otlier rare moths : — ‘ Tliey are ? to be purchased in abundance at IcZ., 2d., or 3d. each, neither '

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