


XIT—THE 
THYRIDIDAE. 
CHAPTER XIl. 
THE THYRIDIDAE. 
Tue Thyrididae are characterized as follows :— 
The maxillary palpi are obsolete. The fore-wings have veins 
8 and 9 usually separate. The hind-wings are without a defined 
pecten of hairs on the lower margin of the cell; vein 1 is absent 
and vein 8 usually free. (See Plate H, figs. 1, 2 and 38). 
This small family is of special interest as it appears 
probable that it ineludes the nearest living representa- 
tives of the ancestors of the Butterflies. Owing to the 
unusual combination of characters displayed by its mem- 
bers systematists have variously placed it with the 
Geometers, the Tortrices, and the Pyrales. Only one 
genus, containing a single species, occurs in New Zealand, 
but the family is fairly well represented in the tropics. 
Genus: 1.—MOROVA, Walk. 
Face prominent. Labial palpi short, stout, subascending, 
with appressed scales, terminal joint very short, obtuse. Fore- 
wings with 8 and 9 short-stalked or approximated towards base. 
Hindwings with 5 tolerably remote from angle, 7 from before 
upper angle, 8 free. (Plate E figs. 1, 2 neuration of Morova 
subfasciata; fig. 3 head of ditto). 
Includes only the following species. 
MOROVA SUBFASCIATA. 
(Morova subfasciata, Walk., Cat., 32, 523; Meyr., Trans. N.Z. 
Inst., XVI., 108; Cacoecia gallicolens, Butl., Voy. Ereb. Terr., 
Ins., 46). 
(Plate XXIV., fig. 25 @; fig. 269.) 
This interesting insect has occurred at Wellington, 
Christchurch, Akaroa, Dunedin, and Invercargill. It is 
probably generally distributed throughout the country, 
although very: rare in the extreme south. 
The expansion of the wings of the male is % inch, of the 
female 1% inches. The costa is strongly arched before the apex 
and the termen of both wings strongly bowed outwards near 
the middle. The male has all the wings and body dark reddish- 
brown with an obscure darker brown central band across the 
middle of both wings; there are numerous scattered fine, dark 
brown wavy marks, and a short curved band from the costa 
before the apex, which does not reach the dorsum. The female 
has the ground colour very bright ochreous-brown, with the 
markings similar to the male, but much more conspicuous Owing 
to the paler ground colour. 
Both sexes vary considerably in size, in the depth of 
the ground colour, and in the intensity of the markings, 
but the male is always much smaller and darker than the 
female. 
The larva inhabits swellings in the stems of Mihlen- 
beckia and Parsonsia during the spring and early sum- 
mer. These swellings are, no doubt, abnormal growths 
which take place in the plant owing to the presence of 
the larva, and are thus similar in their nature to galls. 
The full-grown larva is rather stout with the segments 
deeply excised. The head is small, dark brown and shining; 
the second segment has a large, dark brown, horny dorsal plate; 
the rest of the larva is pinkish-ochreous; the twelfth and thir- 
teenth segments are partially horny on the back; there is an 
obscure dorsal line; segments three to eleven inclusive are fur- 
nished with several very indistinct warts; the legs are small 
and horny and the prolegs minute. 
The pupa les in a chamber in the centre of one of 
the swellings, the larva having previously prepared a 
safe outlet for the moth in the form of a small tunnel 
leading to the air, its extreme end remaining closed by 
a thin pellicle of the original bark, which effectually pre- 
vents the inmate’s resting-place being discovered from 
the exterior. This cavity is also protected by a curtain 
of silk placed just above the tunnel. 
The pupa, which is somewhat elongate, dark brown 
and shining, has a conical sharp-pointed protuberance on 
the top of the head ease, which is probably useful whilst 
forcing its way through the thin pellicle of bark, left by 
the larva at the end of the tunnel. 
The perfect insect appears from December to March. 
It usually frequents open forest or serub where its food- 
plants are often common. It is very active on the wing 
and sometimes flies with rapidity in the hottest sunshine. 
“When at rest the colour and shape of the wings causes 
the insect to closely resemble a crumpled dead leaf. 
This species also oceurs in Fiji. 

