This species (Plate 35, Fig. 3) is easily recognized by its violet-grey
fore wings, and the more or less round, pale, ochreous blotch on the outer
third. The blotch is clouded, to a greater or lesser extent, with pale
brown, and the inner area of the wings is flecked with silvery grey; the
cross lines are edged with reddish brown.
The rather downy caterpillar is yellow, with several interrupted blackish
lines, and of these the one along the middle of the back is the broadest
and blackest; head black. It feeds, during August and September, in
companies, until nearly full grown, and the foliage of almost any kind of
tree or bush appears to be suitable food, although that of elm, lime, and
hazel is often selected by the female moth when depositing her whitish
eggs, which {82} she lays in neatly arranged batches on the undersides of
the leaves. If undisturbed, a company of these caterpillars quickly clear a
fair-sized branch of all leafage. The chrysalis is purplish brown (the
early stages are shown on Plate 37).
The moth flies in June and July, but is rarely seen in the daytime. The
wings in repose are closely folded down to the body and the insect has then
a very stick-like appearance, and may thus easily escape detection.
Occurs throughout England and Wales, Ireland, and Scotland. It is most
common, and the caterpillar often abundant, in London and its suburbs, as
well as other southern parts of the country. Its range extends through
Europe to Northern Asia Minor, Armenia, and Siberia.
THE CHOCOLATE-TIP (_Pygæra curtula_).
Two examples of this moth are shown on Plate 35. Fig. 2 represents the
spring (April and May) form, and Fig. 1 the summer (July and August) form.
Sometimes there is a third brood, in September or October, and Barrett
describes the individuals of this as "pale drab, dusted with darker atoms,
and with the chocolate blotch paler towards the apex." Hybrids have been
obtained from a pairing between _curtula_ female and _anachoreta_ male, and
these were most like the female parent. The early stages are figured on
Plate 34, Figs. 1-1c.
The verdigris-green eggs are laid in batches on the leaves of poplar and
aspen, upon which the caterpillars feed in May and June, and, as a second
brood, in August and September. In colour the caterpillar, which is rather
hairy, is grey, with a pinkish tinge, sprinkled with black, and with orange
spots on the sides; there is a raised black spot on the fourth ring, and
another on the eleventh; head blackish. The chrysalis is reddish-brown,
spun up in a packet of leaves. This species appears to be less common in
England than formerly. It is, {83} perhaps, more often observed in Kent and
Sussex than in the other counties it inhabits, which, according to Barrett,
are Berks, Essex, Suffolk, Norfolk, Cambridge, in all of which it is local;
also, but more rarely, in Gloucestershire, Worcestershire, Herefordshire,
Leicestershire, Yorkshire, and Cumberland, the latter county being its
northern limit. To the above may be added Hertfordshire and Middlesex.
Although caterpillars are reported to have been found in Ireland, the moth
has not been reared in that country.
This species is distributed through Northern and Central Europe, extending
to South France, Corsica, North Italy, Bulgaria, Armenia, and Mongolia.
THE SCARCE CHOCOLATE-TIP (_Pygæra anachoreta_).
This moth is distinguished from that last referred to by the black spots in
and just below the blotch at the tip of the fore wings; the blotch itself
is dull reddish, merging outwardly into greyish, and is intersected by a
white line. There is some variation in the tint of the general colour,
ranging from dusky to reddish grey, but otherwise the species is constant
(Plate 35, Figs. 4, 5).
The caterpillar, which feeds on poplar and sallow from May to August, or
even later, is rather hairy, dark grey or blackish in colour; there are
four ochreous or whitish lines on the back, and a row of black spots
followed by a series of orange ones on the sides; below the spiracles are
some yellowish markings; the raised spots on rings four and eleven are
reddish brown; the former has a white spot on each side, and the back of
the latter is edged with white; head black and rather glossy. Chrysalis
blackish in hue, spun up among leaves. The moths emerge in May, and again
in July; in confinement there is sometimes a third brood in September.
Except that two {84} specimens were reported as found in a street at Deal,
the moth does not seem to have been noticed at large.
This species was known to Haworth, but, as a British insect, was
exceedingly rare until 1859, when Dr. Knaggs found some caterpillars upon
poplar in the neighbourhood of Folkestone. From the stock then obtained the
moths were reared in numbers for some time. Batches of eggs were also put
down in various localities, and the species seems to have flourished in
some of them for a while, but failed eventually to establish itself in any
of them. Then the species disappeared from the Folkestone locality,
although a caterpillar or two were found there in 1861, and on to 1912 in
other places on the Kentish coast. In 1893 eggs were obtained at St.
Leonard's, in Sussex, and thus originated a new stock.
The species has a wide range in Central and Northern Europe, extending to
some of the southern parts; it also occurs in Siberia, Amurland, China, and
Japan.
THE SMALL CHOCOLATE-TIP (_Pygæra pigra_).
This species will be recognized by its smaller size and less distinct
chocolate blotch on the tips of the fore wings. The ground colour varies
from whitish grey to pale brownish grey; the pale cross lines are usually
well defined; the first is bordered with chocolate colour, and angled above
the middle; the third line runs from a white spot on the costa and through
the chocolate patch. The moth is shown on Plate 35, and the early stages on
Plate 34.
Of the offspring resulting from eggs laid by a female _curtula_ that had
paired with a male _pigra_, and also those from a female _pigra_ crossed
with a male _curtula_, the hybrids in each case most nearly resembled the
female parent.
The eggs are pale olive green tending to brownish, and all that I have seen
have been laid in irregular lines on leaves, or {85} on the sides of a chip
box. The caterpillar is greyish, with some short hairs and black dots; the
back is broadly marked with yellow, and there is a yellow stripe, with
black dots on it, low down on the sides; rings four and eleven have each a
raised black spot; head blackish. Feeds from June to September, on dwarf
sallow (_Salix repens_), and also on young plants of aspen. Like other
caterpillars of this genus, it hides by day in a packet of leaves spun
together. There are certainly two broods, if not more, in the year. The
moth emerges in May, and more irregularly in July or August, and October.
Except when attracted to a light, the moth is rarely seen, but in fens,
marshes, and boggy places generally, the caterpillars may often be obtained
in numbers almost throughout the United Kingdom. Its distribution abroad
embraces Northern and Central Europe, with extension into Northern Spain
and Italy; Bulgaria, South-east Russia, and Armenia.