The British species belonging to this family, with one exception, have the
tips of the fore wings pointed and curved downwards, forming a sort of
hook, hence the English name Hook-tips. The exception is _Cilix spinula_, a
round winged moth, not at all like other members of the family, but its
caterpillar is very like others of the group.
The bristle and catch arrangement for locking the wings is present in all
the species, but the tongue or proboscis is absent, or practically so. The
caterpillars are not furnished with anal {133} claspers, therefore have
only fourteen legs, that is, six true legs and eight false legs (pro-legs).
The last ring of the body is more or less tapered, sometimes terminating in
a point; the back is roughened with raised spots and warts, or humped. They
feed on the leaves of trees and bushes, usually exposed, and they pupate in
a silken cocoon, spun up between leaves, or in a folded leaf, of the food
plant.
Of the eleven species occurring in the Palæarctic Region, seven are
European, and six of these are found in the British Isles.
THE PEBBLE HOOK-TIP (_Drepana falcataria_).
The fore wings are brown, whity brown, or whitish; the central area is
crossed by three blackish wavy lines, a blackish blotch in the third line
and two blackish dots between it and the second line; beyond there is a
dark brown, or reddish-brown curved line from the tip of the wing to the
inner margin. Hind wings similar in colour to the fore wings, but paler on
the front area; crossed by five wavy dusky lines, sometimes not well marked
except on the inner margin; generally, there is a black central dot. The
paler forms have a dusky shading on each side of the curved line on the
fore wings.
The egg is yellow freckled with orange, chiefly at one end. Caterpillar
green, the back reddish-brown, except towards the black-marked yellowish
head; two conspicuous warts on rings two to five, and less noticeable
raised spots on the other rings, all bearing hairs. In a younger stage it
is blackish, with white marks on the fourth and seventh rings; later it
becomes greenish below, and the markings on the back of rings four, seven,
eight, and ten are whitish or creamy. Until nearly full grown it usually
lives on the underside of a leaf, the edges of which are turned over and
held down by silken threads; sometimes it may be seen on the upper side of
a leaf under a slight web. It feeds {134} chiefly on birch, but is
occasionally found on alder, in June and July, and in September and
October, and may be obtained by searching or by beating, but the former,
although perhaps slower, is much the better method. The moth is shown on
Plate 68, and the early stages on Plate 69.
The species is widely distributed, and seems to occur, sometimes commonly,
wherever there are birches, especially of bush-like growth, in most English
counties and also in Scotland. In Ireland it appears to be somewhat local
and scarce.
THE SCARCE HOOK-TIP (_Drepana harpagula_).
The general colour of this species is brownish; the fore wings are slightly
tinged with ochreous and speckled with minute violet-tinged silvery scales;
between the first and second brown lines there is an irregular ochreous
brown mark enclosing yellowish spots; the violet-tinted glistening scales
are most in evidence on both sides of the black mark before the outer
margin. Hind wings similar in colour to the fore wings; crossed by two
brown lines, the second with an ochreous brown blotch above it (Plate 68).
Caterpillar, yellow freckled with brown; clouded with brown on first three
rings; a reddish brown irregular stripe runs along the sides and upwards
towards middle of the back on rings five, six, eight, and nine; a
double-pointed hump on the back of ring three, the points tipped with
yellow. Head notched on the crown, dotted and clouded with brown. It feeds
on the small-leaved lime (_Tilia parvifolia_), and may be found from July
to September and even later. I have not seen a living caterpillar of this
species; the above short description has been drawn from an inflated skin
(Plate 69).
The only British locality for this species is the Leigh Woods near Bristol,
where it was first met with in 1837. It is, however, very rare and
difficult to obtain. Abroad it ranges through Central Europe to Livonia,
Southern Sweden, and to Northern Italy. On the Continent the caterpillar
feeds on the foliage of other trees than lime, and there are two broods in
the year.
[Illustration]
Pl. 68.
1. SCARCE HOOK-TIP, _male_; 2 _female_.
3, 5, 6. PEBBLE HOOK-TIP, _males_; 4, 7 _females_.
[Illustration]
Pl. 69.
1, 1a, 1b. SCALLOPED HOOK-TIP: _eggs, caterpillar and chrysalis_.
2, 2a, 2b. PEBBLE HOOK-TIP: _caterpillar, chrysalis and cocoon_.
3. SCARCE HOOK-TIP: _caterpillar_.
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THE OAK HOOK-TIP (_Drepana binaria_).
The male is of an ochreous-tinged brown coloration; all the wings are
crossed by two slender deep ochreous lines, and have two obliquely set,
almost central, black dots; outer margin of fore wings often blackish,
marked towards the tip; the hind wings are deep ochreous on the front
marginal area. Fore wings of the female paler, and the hind wings ochreous
yellow; the cross lines on the latter often lost in the ground colour
(Plate 71).
In freshly emerged male specimens the brown is sometimes purplish tinged,
and in some examples of the same sex the hind wings may be described as
ochreous, with brown bands. The female occasionally has the fore wings
tinged with greyish, and the hind wings are sometimes banded with brown,
especially on the inner marginal area.
The caterpillar is ochreous brown with a double-pointed hump on ring three,
a yellowish diamond on the back of rings five to ten; the front and hind
rings are brown, more or less tinged with purple; yellowish lines, shaded
below with purplish brown, on the sides meet on the back and form an edging
to the diamond mark. The figure on Plate 70 shows the caterpillar in its
usual resting attitude. It feeds on oak.
A widely distributed species in the southern half of England, but not
especially abundant in any locality, and not known to occur north of
Lincoln.
THE BARRED HOOK-TIP (_Drepana cultraria_).
Fore wings pale fulvous or ochreous brown, with two paler cross-lines on
all the wings, space enclosed by the lines darker brown; a black or
blackish central dot, and before the brownish {136} outer margin there is a
pale line ending on the tip of the wing. The hind wings have an obscure
dusky central dot placed in the upper edge of the band, and usually there
are two brownish bands on the outer marginal area, but these do not extend
to the front margin. Except that the female is generally larger, and the
antennæ are simple, the sexes are much alike (Plate 71).
This species is best distinguished from _binaria_ by the dark bands, and
the straighter second line. The central dots are less trustworthy
characters, because summer specimens of the present species often have two
of these spots on the fore wings (var. _æstiva_, Spr.), and in occasional
examples of _binaria_ the lower central spot of the hind wings is absent.
As a rule, however, the central dots are more conspicuous in _binaria_ than
in _cultraria_. The egg is yellowish, tinged with reddish at the ends and
along the sides. The caterpillar is somewhat similar to that of the last
species, but the hump on ring three is smaller, and the side lines and
diamond mark are whiter. It may be found in June and July, and again in
September, and even in October in some years. It feeds on beech (Plate 70).
This species is found where beech trees occur, preferably on a chalky soil,
in the counties of England from Norfolk southwards. The male may often be
seen in May, flying around the beech trees or neighbouring bushes, in the
sunshine; or both sexes may be caused to leave their resting places among
the foliage by tapping the boughs.
Its range extends through Central Europe to Asia Minor.
THE SCALLOPED HOOK-TIP (_Drepana lacertinaria_).
The name Scallop Hook-tip given to this species by Moses Harris in 1775,
doubtless referred to the ragged outlines of the fore wings. These wings
are pale brown in colour, freckled and clouded with darker tints, and
crossed by two dark-brown lines; the central dot is black, but often
minute; fringes {137} white, chequered with brown. Sometimes the freckling
is heavy and the clouding very dark, becoming almost black on the outer
margin; such specimens seem to be referable to var. _scincula_, Hübn. In
another form the fore wings are ochreous brown, with very tiny freckling
and only light clouds on the upper part of the outer margin. The hind wings
in all the forms are pale whitish brown, with a black central dot, and
brown marginal line; in the darker specimens these wings are clouded or
suffused with dark brown (Plate 71).
The egg is pale yellowish when laid, but changes afterwards to reddish. The
full-grown caterpillar is pale brownish, marked with darker or reddish
brown on the back and sides, and raised spots; there are double-pointed
humps on rings two and three, and a similar but smaller elevation on ring
eleven. In the younger state the caterpillar is blackish, with whitish
marks on the fourth, seventh, and eighth rings, and some white dots on the
end rings. It feeds on the upper surface of the leaves of birch in June and
July, and again in August and September.
Chrysalis, reddish brown, the ring divisions blackish grey; powdered with
whitish, and appearing as though dusted with flour. Attached by the anal
spike to the interior of the silken web-like cocoon. In the Figure (Plate
69) the pupa is shown hanging from the ruptured cocoon, upon the covering
leaf of which a half-grown caterpillar is depicted.
The moth is out in May and June, and a second generation appears in August.
It is not uncommon in most birch woods, and on heaths and commons, where
birch flourishes; but the perfect insect, which rests on leaves and twigs
of trees and bushes, and the herbage under them, is not so frequently or so
easily obtained as the caterpillars. The latter may be searched for in the
daytime, or they may be dislodged by beating.
Widely distributed throughout England, but local or scarce in Lancashire
and Yorkshire and northwards; also, according to {138} Barrett, in
Devonshire and in the fens of Norfolk and Cambridge. It occurs in the
Clydesdale district, Ross, Argyllshire, and Sutherland in Scotland; and in
Ireland it seems to be widely spread and common in some localities.
THE CHINESE CHARACTER (_Cilix glaucata_).
Probably in reference to the grey-brown oval blotch on the middle of the
white fore wings, this moth was known to the older entomologists by the
English name of "Goose-egg." On the blotch, however, there are silvery
marks on the veins, and below it (often attached) there is a blackish
blotch with some bluish silvery scales upon it. These markings probably
suggested to Haworth the name Chinese Character by which it is commonly
known (Plate 71).
The caterpillar is reddish brown, with a darker line along the back, and a
paler patch on rings three to five, extending as a narrow stripe to the
dark-brown spiked tail; two raised warts on rings two and three, with a
white dot between the hinder pair. Head darker brown, paler in front. It
feeds in June and early July, and in September and October, chiefly on
hawthorn and sloe, but it will also eat apple and pear. The chrysalis,
which is enclosed in a brown, rather tough, silken cocoon, spun up among
leaves or under loose bark, is greyish on the wing covers, and reddish on
the body.
The moth is out in May and early June, and again from late July well into
August. Sometimes it may be seen resting on a leaf in a hedgerow. When
disturbed in the daytime, which may happen where one is beating the bushes,
it falls, rather than flies, to the ground. At night it may be netted as it
flies along the hedgeside or wood borders in almost every county of England
and Wales. In Scotland its range seems not to extend north of Clydesdale.
Kane states that it is "widely spread, but not generally at all numerous"
in Ireland.
[Illustration]
Pl. 70.
1. OAK HOOK-TIP: _caterpillar_.
2, 2a, 2b, 2c. BARRED HOOK-TIP: _egg, enlarged; caterpillar, chrysalis
and cocoon_.
[Illustration]
Pl. 71.
1. OAK HOOK-TIP, _male_; 2 _female_.
3. BARRED HOOK-TIP, _male_; 4 _female_.
5, 7. SCALLOPED HOOK-TIP, _males_; 6, 8 _females_.
9. CHINESE CHARACTER, _male_; 10 _female_.
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