British Insects: the Families of Lepidoptera
British Insects: the Families of Lepidoptera |
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~Nymphalidae-Danainae.
Adults diurnal; very large; relatively very short-bodied; slender-bodied to medium built; wings in repose apposed vertically over the back.
Head rough. Antennae very short; extending to about 0.3–0.4 times the length of the forewing; inserted markedly less than one half the width of the head apart; clubbed. The club gradual. Antennae of males simple; non-ciliate. Eyes glabrous. Ocelli absent. Chaetosemata present. Maxillary palps much reduced; 1 segmented. Labial palps ascending; 3 segmented. Proboscis fully developed; not scaly.
Wingspan 90–120 mm; 12–15 times the thoracic width. Forewings broad; about 1.7–1.8 times as long as wide. The outer and hind margins angled at about 110 degrees. The outer margin concavely curved; forewings apically blunt; ground colour predominantly orange-brown; forewings without eye-spots above. Hindwings broadly rounded; similar in breadth to the forewings; the upper surfaces conspicuously patterned above; with neither discal spot nor transverse lines (with the conventional lepidopterous lines and discal marks lacking or more or less obscured); without a frenulum.
Neuration of forewings and hindwings dissimilar. Forewings 12 veined; with 1 anal vein. The anal veins of the forewings representing 1b only. Forewings lacking a tubular vein 1c. Vein 1b of the forewings furcate proximally to simple (?). Discal cell of the forewings without a tubular media (M) vein. Hindwings 9 veined; with 2 anal veins. The anal veins of the hindwings comprising 1a and 1b. Hindwings exhibiting vein 1a; lacking a tubular vein 1c; with a praecostal spur. The hindwing cell emitting more than six veins. 7 veins arising from the hindwing cell. The cell-derived hindwing veins 3+4 proximally joined. Vein 8 of the hindwings arising from the upper margin of the cell (from near its base); not approximating to vein 7.
Adults having only 4 fully developed legs. Fore-legs of female useless for walking. Fore-legs without a tibial epiphysis. Tibiae of middle legs 2-spurred. Posterior tibiae 2-spurred.
Tympanal organs absent.
Eggs, larvae and pupae. Eggs not flattened (truncate-fusiform); ribbed and/or reticulate. Larval prolegs 10. Larvae with a pair of tentacles from segment 2 (and another, shorter pair on segment 12); without bristly spines; exposed feeders; not feeding in communal tents. On Asclepiadaceae and Apocynaceae.
Pupae smooth and rounded; conspicuously patterned; with shining-metallic spots; exposed, with no coccoon; suspended from the tail (cremaster), with no median silk girdle.
British representation. Genera 1; 1 species. Danaus plexippus (Milkweed, Monarch), adventive.
Classification. Butterflies. Suborder Ditrysia. Superfamily Papilionoidea.
General comments. Famous migratory butterflies, distasteful to predators.
Illustrations: • Danaus plexippus (Milkweed, Monarch: Morris).
To view the illustrations with detailed captions, go to the interactive key. This also offers full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2003 onwards. British insects: the families of Lepidoptera. Version: 9th June 2008. http://delta-intkey.com’.
