The figures of caterpillar and chrysalis on Plate [93] are from Buckler's "Larvæ of British Butterflies."
Some caterpillars, from eggs laid in May or June, become full-grown in four or five weeks, and appear as butterflies in August, but others do not complete their growth until the following spring. Just exactly what happens in the case of eggs from autumn females does not seem to be very definitely ascertained. It has, however, been stated that caterpillars hatching from eggs laid in August, attain the size of the slow-growing contingent from May eggs, and then hibernate. Probably, therefore, it is these that produce the July butterflies, and if so, the succession of emergences may be something in this way: May and June butterflies from May and June eggs (twelve months' cycle), July butterflies from August eggs (eleven months cycle), August and September butterflies (partial second brood) from May and June eggs (four months' cycle).
This interesting little butterfly is to be seen almost everywhere, but it is perhaps most frequently to be found in grassy places in lanes, on heaths and downs, railway banks, in rough meadows, etc. It occurs on mountains even up to an elevation of 2000 feet. When flying in company with the blues and coppers, all frolicking together over some patch of long grass, the colour combination has an exceedingly pleasing effect. They rest by day, and sleep at night on grass or rushes.
A common species throughout England and Wales, Ireland and Scotland, as far north as Nairn, also in the Outer Hebrides. Abroad its distribution extends over Europe to South-West Siberia, Central and North-East Asia, Asia Minor, and North Africa.
We now arrive at the Hairstreaks, Coppers, and Blues. These belong to the Lycænidæ, a very large family of butterflies which is represented in all parts of the globe. There are eighteen species in Britain, but at least one of these is extinct and another is supposed to be so; two are very rare, and the chances of meeting with either are probably about equal.
The Brown Hairstreak (Zephyrus betulæ).
The butterfly is represented on Plate [94,] Figs. 1-3. The male is blackish-brown with a faint greyish tinge, and there is a conspicuous black bar at the end of the discal cell of the fore wing, followed by a pale cloud; there are two orange marks at the anal angle of the hind wings. The female is blackish-brown, and has the black bar at end of the cell, and an orange band beyond; there are usually three orange marks on the hind wings at the anal angle, but sometimes there are only two. The under side of the male is ochreous, but that of the female is more orange; the fore wings have the black bar edged on each side with white, and there is a white-edged, brownish triangular streak beyond, the outer margin is tinged with reddish; on the hind wings there are two white irregular lines and the space between them is brownish, the outer margin is reddish, becoming broadly so towards the anal angle, where there is a black spot. Variation is not of a very striking character. The shade following the black bar at end of the discal cell on the fore wings in the male is sometimes yellowish tinged, not infrequently fairly large, and with two smaller spots below it. More rarely all three spots are distinctly ochreous-yellow (var. spinosæ, Gerhard). A similar aberration, but with the marks white instead of yellow, has been named pallida, Tutt. The orange band in the female varies in width and in length; occasionally it extends well below vein 2, and into the discal cell within the black bar. I have one specimen in which the band is broken up into three parts, and the upper one of these is but little wider than the same spot in var. spinosæ, the other two being almost exactly of the same size as in that variety.
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