Insects of Britain and Ireland: the families of Lepidoptera

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L. Watson and M. J. Dallwitz

Blastobasidae

Adults small; relatively long-bodied; medium built (wingspan more than 8 and less than 15 times the thoracic width); wings in repose packed with the forewings directed backwards to cover hindwings and abdomen.

Head smooth. Antennae of medium length; extending to about 0.6–0.7 times the length of the forewing; inserted fully one half the width of the head apart; not clubbed. Antennae of males simple; simply-ciliate. The antennal scape with a pecten (this dense); expanded laterally and concave beneath, forming an ‘eye cap’, or not forming an ‘eye cap’. Eyes glabrous. Ocelli absent. Chaetosemata absent (?). Maxillary palps well developed; 4 segmented; folded. Labial palps well developed (long); ascending (recurved). Proboscis fully developed; scaly towards the base.

Wingspan 12–23 mm; about 11–12 times the thoracic width. Forewings narrow; about 3.8–4.8 times as long as wide. Tornus undetectable. The outer margin convexly curved; forewings apically blunt; ground colour predominantly fuscous, “obscure and dull coloured moths, decidedly the least attractive family of Lepidoptera” according to Meyrick!. Hindwings narrow-elongate and very long-fringed; lanceolate; quite markedly narrower than the forewings to similar in breadth to the forewings; with a rounded apex. The fringe of the hindwings 2 times the width of the membrane. The upper surfaces plain; with neither discal spot nor transverse lines; hindwings with a frenulum.

Neuration of forewings and hindwings dissimilar. Forewings 12 veined; with 2 anal veins. The anal veins of the forewings comprising 1b and 1c. Forewings exhibiting a tubular vein 1c (complete distally). Vein 1b of the forewings furcate proximally. The transverse vein complete. Discal cell of the forewings without a tubular media (M) vein. Hindwings 7 veined, or 8 veined; with 2 anal veins. The anal veins of the hindwings comprising 1b and 1c. Hindwings lacking vein 1a; exhibiting a tubular vein 1c. Vein 1b of the hindwings furcate proximally, or simple. The transverse vein complete, or incomplete. 5 veins arising from the hindwing cell (then vein 4 supposedly absent), or 6 veins arising from the hindwing cell. The cell-derived hindwing veins 3+5 proximally joined (supposedly, in Blastobasis), or 4+5 proximally joined. Vein 8 of the hindwings anastomosing with the upper margin of the cell (near its base), or arising from the upper margin of the cell (?); not approximating to vein 7.

Fore-legs with a tibial epiphysis. Tibiae of middle legs 2-spurred. Posterior tibiae 4-spurred; hairy (with long, fine hairs).

Eggs, larvae and pupae. Larval prolegs 10. Larvae exposed feeders (feeding on fallen fruits, seeds and dry detritus, decaying wood, and in stored products).

Pupae concealed. Empty pupae not becoming protruded.

British representation. Genera 2 (Auximobasis, Blastobasis); 4 species (all adventive or naturalized).

Classification. Microlepidoptera. Suborder Ditrysia. Superfamily Gelechioidea.

Illustrations. • Blastobasis lignea: neuration.


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Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2003 onwards. Insects of Britain and Ireland: the families of Lepidoptera. Version: 8th June 2016. delta-intkey.com’.

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