Insect Order Lepidoptera - butterflies,
moths
Lepidoptera are Holometabolous insects
(insects which have larvae that look nothing like the adults/imagos and
having a complete metamorphosis with a pupal stage). They possess
two pairs of membraneous wings with few cross veins, (though these may
be absent in the females of some moths). The mandibles are present in the
larvae but nearly always absent in the imagos/adults in whom the principal
mouth parts are a sucking tube or proboscis formed from the maxillae which
is held curled up in a spiral under the head when not in use (in a number
of species of Moths the mouthparts are all degenerate in the imagos and
these do not feed at all. The antennae are variable in length and may be
quite complicated in some male moths The imagos have two large compound
eyes with as many as 6 000 omatidium and two ocelli, while the larva often
have simple ocelli. The wings and body of the imagos are covered in scales
and the body of the larva are generally covered in hairs (though these
may be very fine and short). The salivary glands of the larvae have become
modified to form the silk glands. The larvae are 'eruciform' (which means
they look like a caterpillar) and in most cases have 13 body segments with
three pairs of jointed legs on the first three segments, (which are roughly
equivalent to a thorax in the imago). Segments 3 to 6 of the abdomen (6,7,8,9
counting back from the head with the head as 0) each have a pair of unjointed
pro- or false-legs, these end in a contractile pad surrounded by a ring
of minute hooks; there is also a pair of unjointed claspers on the final
segment.