TRACHEATA 353 
the female of which has rudimentary wings. Midonia piniaria 
attacks Conifers. 
II. NOCTUINA. 
The group includes the forms popularly known as owlets ; 
it is the largest group of the Lepidoptera, containing over 2500 
species. Most nocturnal moths of fair size belong to it. The 
antennae are long, sometimes pectinate in the male. The fore- 
wings are small, and the larger posterior wings are folded under 
them when at rest. They are usually of a dull colour, and 
there is almost always a round spot and a kidney-shaped patch 
in the middle of the anterior wing. There is little variation 
between the sexes, or between the different species in the moth, 
but the caterpillars differ considerably. The latter are striped 
and barred, naked, or more rarely hairy ; they usually have five 
pairs of pro-legs, but some have four. The pupae are usually 
underground, enclosed in earthen cocoons. The eggs are laid 
singly, and the larvae are not gregarious. 
The Noctuina include numerous families, amongst whom 
the Plusiidae, the Agrotidae, and the Ophiusidae may be 
mentioned. 
III. BOMBYCINA. 
The members of this group are often termed spinners. 
They are large unwieldy moths, often very beautiful and 
strange in form. ‘Their body is usually very hairy (Fig. 198), 
the head is small and sunken, and the mouth parts are reduced 
and sometimes obsolete. The antennae are setiform, in the 
male pectinate; the last-named sex are as a rule more 
brilliantly coloured and more active than the sluggish female. 
The wings of the female Orgyia are reduced, and are absent 
altogether in Psyche. The eggs are laid in groups, and are 
covered with a woolly substance; the caterpillars have sixteen 
legs, and are usually hairy. The cocoons are made above 
ground, the naked larvae forming theirs of silk, the more hairy 
kinds mixing their hairs with a slighter amount of silk. The 
sexes are usually very distinct, and the females attract the 
males from great distances. Parthenogenesis occurs in the 
family Psychidae. 
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