Butterflies and Moths Order Lepidoptera

Identification: With 4 membranous wings (rarely wingless), HW a little smaller than FW, the wings largely or entirely covered with scales. Mouth parts sucking, the proboscis usually in the form of a coiled tube. Mandibles nearly always vestigial or lacking. Labial palps usually well developed and conspicuous; maxillary palps generally vestigial or lacking. Antennae long, slender, sometimes plumose, always knobbed apically in butterflies. Metamorphosis complete.

Similar orders: (1) Trichoptera (p. 210): few or no scales on wings; no coiled proboscis; maxillary palps well developed; M in FW usually 4-branched (3-branched in Lepidoptera). (2) Hymen-optera (p. 312): no scales on wings; mouth parts chewing, with well-developed mandibles.

Immature stages: Lepidopterous larvae are commonly called caterpillars. They are usually cylindrical, with a well-developed head, 3 pairs of thoracic legs, and 5 (sometimes fewer) pairs of abdominal prolegs. The prolegs are short and fleshy and are provided with a number of tiny hooks (crochets); they are normally present on 4 consecutive segments near the middle of the body (abdominal segments 3-6) and on the last segment. Larvae lack compound eyes but usually have a group of small ocelli on each side of the head. Many caterpillars are ornamented with hairs or spines, and although some look very ferocious most are quite harmless to handle. A few give off an unpleasant odor when disturbed, and a few have body hairs that can sting or irritate the skin. Lepidopterous larvae have the salivary glands modified into silk glands; the silk is spun from the mouth and used principally in making cocoons or shelters. Many larvae pupate in silken cocoons; others make no cocoon. Most butterfly larvae make no cocoon, and their pupae are often called chrysalids (singular, chrysalis); chrysalids are often tuberculate or sculptured, and sometimes brightly colored; moth pupae are usually brownish and smooth. Most caterpillars are external feeders on foliage; a few live inside leaves as leaf miners, a few are gall makers, and a few bore into fruit, stems, and other parts of a plant. A very few caterpillars are predaceous on other insects.

Habits: Adult Lepidoptera feed principally on nectar and other liquid food, and many are common on flowers; a few do not feed as adults. Their flight is usually rather erratic but fairly fast. A few butterflies migrate long distances.

Importance: The larvae of many species are serious pests of cultivated plants; a few are pests of stored foods (grain, flour, and meal), and a few are pests of fabrics.

ocellus ocellus


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