British Butterfiles Part 17

(Plate XIV. fig. 1.)

This is the _largest_ of all our "Blues," and, next to the last, the rarest, though still taken in some numbers every year.

_Colouring_:--Upper side, _dark blue_, granulated with black scales that give it a dull aspect, having a black border, and a series of _large black spots across the front wing_. Under side, greyish drab, suffused with greenish blue near the body; towards centre, many black spots in indistinct light-coloured rings, and a double border of the same. _No red spots._

The _caterpillar_ is _unknown_.

The _b.u.t.terfly_ appears in July, frequenting rough, flowery pasture-grounds, but is exceedingly local. A famous place for it is Barnwell Wold, about a mile and a half from the village of Barnwell, near Oundle, Northamptonshire, where the insect was discovered by the Rev. W.

Bree many years ago; but it is less abundant there than formerly, from the repeated attacks of collectors, who catch all they can find. Other localities, mentioned in various works, are--Brington, Huntingdonshire; Shortwood, and some other spots, near Cheltenham; Charmouth, Dorsetshire; Dover; Downs {155} near Glas...o...b..ry, Somerset; Downs near Marlborough, Wiltshire; Broomham, Bedfordshire; near Bedford; near Winchester.

THE CHALK-HILL BLUE. (_Polyommatus Corydon._)

(Plate XIV. fig. 2, Male; 2 _a_, Female.)

_Colouring_:--Upper side, _male, pale silvery greenish blue_, with very silky gloss, and shading off into a _broad black border_.

Female, dark smoky brown, with a leaden tinge, sprinkled near the body with _greenish_ blue scales of the _same colour_ as the males; border of orange spots, more or less visible. _Under side_ marked as in fig. 2 _a_, on a brown ground, with a row of _red_ spots near border of hind wing.

The _caterpillar_ (Plate I. fig. 10) is green, striped with yellow on the back and sides.

The _chrysalis_ is brownish, and of the shape shown at fig. 29, Plate I.

The _b.u.t.terfly_ is out in July and August, frequenting chalky downs, especially in the south, and where it does occur is often extremely abundant. Occasionally it is found _off the chalk_, having been seen in Epping Forest, decidedly _not_ a chalk district. Other localities {156} are--Croydon; Brighton; Lewes; Dover; Winchester; Isle of Wight; Halton, Bucks; Newmarket; Peterborough; Norfolk; Suffolk; Berkshire; Oxfordshire; Wiltshire; Gloucestershire. At Grange, North Lancashire, it is the commonest "Blue," _not on chalk_, but _limestone_.

THE ADONIS BLUE. (_Polyommatus Adonis._)

(Plate XIV. fig. 3, Male; 3 _a_, Female.)

_Colouring_:--Upper side, _male, brilliant sky-blue, without any lilac tinge_, bordered by a distinct black line, the _fringe distinctly barred with blackish_. Female, dark smoky brown, sprinkled near body with _pure blue scales the colour of those of male_; border of orange spots, more or less visible.

Under side, male, marked as in fig. 3; border of red spots.

Female, almost exactly like that of Corydon (fig. 2 _a_), but usually has the black spots on the front wing smaller.

This is a most lovely little b.u.t.terfly, the blue of its upper surface being quite unapproachable among native insects. Mr. Stainton, speaking of the different blues of Corydon and Adonis, happily observes that, "_Corydon_ {157} reminds one of the soft silvery appearance of _moonlight_, whilst _Adonis_ recalls the intense blue of the sky on a hot summer's day."

_Caterpillar_ like that of Corydon.

The _b.u.t.terfly_ is double-brooded, appearing first in May and again in August. It is found on the same soils and in most of the localities with the last, but is, I believe, more confined to the south.

THE COMMON BLUE. (_Polyommatus Alexis._)

(Plate XIV. fig. 4, Male; 4 _a_, Female.)

_Colouring_:--Upper side, male, lilac blue. Female, purplish blue about the centre, brown towards the margins, but the proportions of blue and brown are very variable--sometimes all the wings have a border of orange-red spots, sometimes these are absent from one or both pairs of wings.

_Fringe_ in both s.e.xes _white, uninterrupted by dark bars_.

_Under side_, male, marked as in fig. 4, and hardly to be distinguished from under side of male Adonis, except by the ground colour, which is paler and _greyer_ than in Adonis. Female, same pattern as male, but coloured with warmer tints--more like male Adonis. {158}

This very pretty little insect is the blue b.u.t.terfly one sees everywhere, abounding in meadows, on heaths and downs, and not at all confined to chalky soils, like some other "blues."

The _caterpillar_ is green, with darker stripe on the back, and white spots on each side. It feeds on Bird's-foot Trefoil and other leguminous plants.

The _b.u.t.terfly_ is to be found almost constantly from the end of May to the end of September, being double-brooded.

THE SILVER-STUDDED BLUE. (_Polyommatus aegon._)

(Plate XIV. fig. 5, male; 5 _a_, Female.)

_Colouring_:--Upper side, _male, purplish blue_ (rather deeper than that of Alexis), with a rather broad black margin. Female, dark brown, sometimes slightly tinged with blue, and bordered on the hind wings with dull orange spots; but these are often absent.

Fringe white, _not_ barred with black. Under side, _near the margin of the hind wings_, and between that and the orange border spots, are several _metallic spots, of a bluish tint_, whence the insect has its name of "Silver-studded." {159}

The _caterpillar_ is brown, with white lines. Feeds on broom and other plants of the same order.

The _b.u.t.terfly_ appears in July and August, and is very frequently met with throughout the country on heaths, commons, and downs, both on sandy and chalky soils. In many places it is the commonest of the "Blues." It has been found at Epping; Coombe Wood; Darenth Wood; Box Hill; Ripley, Surrey; Brighton; Lewes; Deal; Lyndhurst; Blandford; Brandon, Suffolk; Holt, Norfolk; Birkenhead; Bristol; Sarum, Wiltshire; Lyme Regis; Parley Heath, Dorsetshire; Manchester; York; several places in Scotland.

THE BROWN ARGUS. (_Polyommatus Agestis._)

(Plate XIV. fig. 6.)

Though this b.u.t.terfly and the next are cla.s.sed among the "Blues," from their possessing the same structure and habits, there is _no trace of blue_ in the colouring of _either s.e.x_, as in all the preceding species of _Polyommatus_.

In this species the colour of both s.e.xes on the upper side is a _warm, dark brown_, having on all the wings a border of dark orange spots. The female hardly differs from the male, except in having this border broader, and more extended on the front wing; where, {160} in the male, it is sometimes very indistinct. The under side much resembles that of the female of _Alexis_, the border of orange spots being even more distinct on the front wing than on the hind one. It will be observed on referring to Plate XIV.

that on the under sides of all the b.u.t.terflies there figured, there is an irregular black spot situated near the front edge of the upper wing and midway in its length--this is called the "_discoidal spot_." It will also be observed that the common Blue (fig. 4) has, on the area of the wing, between the discoidal spot and the root of the wing, two spots, which are _absent in this species_. This forms a very ready mark of distinction, though it requires a good many words to explain it.

The _caterpillar_, which feeds on _Erodium Cicutarium_, and perhaps on _Helianthemum_ (Rock Cistus), is green, with pale spots on the back, and a brownish line down the middle.

The _b.u.t.terfly_ appears in May and June, and again in August, and is common in very many localities in the south, being particularly abundant on the downs of the south coast and the Isle of Wight.

{161}

THE ARTAXERXES b.u.t.tERFLY. (_Polyommatus Artaxerxes._)

(Plate XIV. fig. 7.)