Insects of Britain and Ireland: the families of Lepidoptera

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L. Watson and M. J. Dallwitz



Adults diurnal; relatively long-bodied (exaggeratedly so); medium built (wingspan more than 8 and less than 15 times the thoracic width) to heavily built (wingspan less than 8 times the thoracic width). The abdomen conspicuously patterned (black, usually with yellow or red bands). Adults of hymenopterous appearance.

Head rough (-scaled). Antennae of medium length to long; extending to about 0.55–0.84 times the length of the forewing; clubbed to not clubbed. The club when present, gradual. Antennae of males sub- dentate, or simple, or lamellate; non-ciliate, or fasciculate-ciliate (usually penicillate). The antennal scape without a pecten. Ocelli present (prominent). Chaetosemata absent. Maxillary palps much reduced. Labial palps ascending; 3 segmented. Proboscis fully developed; not scaly.

Wingspan 16–45 mm; 5–10 times the thoracic width. Forewings narrow; 3.2–4 times as long as wide. The outer and hind margins angled at 120–135 degrees. The outer margin convexly curved; forewings apically blunt. Hindwings similar in breadth to the forewings; with a rounded apex; the upper surfaces conspicuously patterned above (at least via the dark veins, and sometimes with pigmented outer margins and/or costa); with a discal spot (or a bar over the transverse vein), or with neither discal spot nor transverse lines (Sesiinae only); with a frenulum.

Neuration of forewings and hindwings dissimilar. Forewings 12 veined, or 13 veined; with 1 anal vein, or with 2 anal veins. The anal veins of the forewings representing 1b only, or comprising 1b and 1c (with 1c vestigial save at its base). Forewings exhibiting a tubular vein 1c (proximally only), or lacking a tubular vein 1c (?). Vein 1b of the forewings furcate proximally. The transverse vein complete to incomplete. Discal cell of the forewings without a tubular media (M) vein. Hindwings 8 veined, or 9 veined; with 3 anal veins. The anal veins of the hindwings comprising 1a, 1b and 1c. Hindwings exhibiting vein 1a; exhibiting a tubular vein 1c. Vein 1b of the hindwings furcate proximally. The transverse vein incomplete. 5 veins arising from the hindwing cell (vein 5 absent). The cell-derived hindwing veins all arising independently of one another, or 3+4 proximally joined (these then connate to stalked). Vein 8 of the hindwings completely independent of the cell (but concealed in the costa and hard to detect); approximating to vein 7 beyond the cell (but vein 8 ostensibly absent, being concealed in the costa).

Fore-legs with a tibial epiphysis. Tibiae of middle legs 2-spurred. Posterior tibiae 4-spurred.

Tympanal organs absent.

Eggs, larvae and pupae. Larval prolegs 10. Larvae concealed feeders; wood- or stem- boring (or in roots). On divers woody and herbaceous Dicots, feeding in the stems and roots.

Pupae concealed (in the larval galleries); in stems, or in wood. Empty pupae protruded from place of concealment.

British representation. Genera 7; 15 species. Aegeriinae: Bembicia ichneumoniformis (Six-belted Clearwing), Paranthrene tabaniformis (Dusky Clearwing), Pyropteron chrysidiformis (Fiery Clearwing), Synansphecia muscaeformis (Thrift Clearwing), Synanthedon anthraciniformis (Orange-tailed Clearwing), Synanthedon culiciformis (Large Red-belted Clearwing), Synanthedon flaviventris (Sallow Clearwing), Synanthedon formicaeformis (Red-tipped Clearwing), Synanthedon myopaeformis (Red-belted Clearwing), Synanthedon scoliaeformis (Welsh Clearwing), Synanthedon spheciformis (White-barred Clearwing), Synanthedon tipuliformis (Currant Clearwing), Synanthedon vespiformis (Yellow-legged Clearwing). Sesiinae: Sesia apiformis (Hornet-moth), Sesia bembeciformis (Lunar Hornet Clearwing).

Classification. Macromoths. Suborder Ditrysia. Superfamily Sesioidea.

Illustrations. • The Sesiidae: Newman. • Assorted Sesiidae: Kirby. • Bembecia ichneumoniformis (Six-belted Clearwing: B. Ent. 53). • Bembecia ichneumoniformis: B. Ent. 53, legend. • Bembecia ichneumoniformis (dissections: B. Ent. 53). • Sesia bembeciformis (*Lunar Hornet Clearwing), Sesia apiformis (**Hornet-moth): B. Ent. 372. • Sesia bembeciformis and Sesia apiformis: B. Ent. 372, legend+text. • Sesia bembeciformis and Sesia apiformis: B. Ent. 372, text cont.. • Synanthedon spheciformis, S. vespiformis, S. myopaeformis, S. formicaeformis: Stephens I, 188. • Sesia apiformis: 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.’.