AEGERIIDAE. By M. Bartel. 375 



25. Family: Aegeriidae (Sesiidae). 



A well-defined family, whose species are related to the Cossids, their larvae having the same habito 

 as in that fanaily. The moths of the Aegeriidae resemble Hymenoptera and many species bear names refer- 

 ing to members of that order. The popular name of "Clearwing" sufficiently characterises this family, 

 by far the greater number of species having entirely vitreous hindwings and the forewings provided with 

 more or less large hyaline spots. The forewing bears as a rule 3 such vitreous patches, the wedge-spot 

 in the cell, the longitudinal area below the cell at the hind margin, and the distal vitreous 

 area in the proximal portion of the distal-marginal area. The hyaline patches are rarely rudimentary (in 

 Paranthrene, Dipsosphecia, Chamaesphecia a. o.), while in Sphecia and ^egfefw the forewings are almost entirely 

 vitreous or bear only sparse scaling which breaks off during flight. Microsphecia, however, has the forewing entirely 

 scaled. In a very few species also the hindwing is completely scaled (e.g., in 9of Z>. tancrei Pilng., and W. agdisti- 

 formis Stgr.), although not so densely as in other families. The forewing is exceedingly elongated and narrow, 

 being somewhat broader towards the distal margin; the margins are scaled, and usually also the cross-vein 

 bears a more or less broad or very narrow band. The hind margin is scarcely curved, the distal margin short 

 and oblique, the hind angle rounded. Areole absent. With 11 or 12 veins. Vein 1 a of the fore\ving close 

 to the hind margin or only marked as a chintinous fold, sometimes forked at the base; 2 — 11 from the cell, 5 

 sometimes absent ; 7 and 8, with the exception of Microsphecia, on a long stalk ; 1 b strongly reduced, 1 c 

 absent. Hindwing mostly with scaled margin, somewhat shorter but much broader than the forewing, the 

 abdominal margin short, the distal one oblique, and the anal angle rounded, with 3 submedian veins; the 

 thin inner submedian vein basally forked and usually forming a distinct loop, either the anterior or the 

 posterior branch reaching to the distal margin; lb almost always reaching to the distal margin or distally 

 vestigial, vein 5 absent, 7 and 8 coincident; frenulum always well-developed in both sexes. Antenna usually 

 gradually incrassate distally, ending in a short point bearing a brush of hairs; in some genera (Bembecia 

 Microsphecia) setiform. Eyes naked, ocelli large. Palpi well-developed, rough-scaled; maxillary pa Ipi aborted 

 Proboscis mostly distinct, but obsolescent in some genera or absent. Thorax robust. Abdomen in (^ with 

 7, in 5 with 6 segments, usually terminating with a tuft of hair. Legs strong and mostly long, with the tibia 

 strongly scaled or hairy, sometimes bearing some separated tufts of hair; mid tibia with end-spurs, hind tibia 

 with strong mid-and end-spurs; fore tibia much shorter than the femur, with long epiphysis. 



Mo.st specie* very small to moderately small, one-brooded, and flying very briskly in the sunshine. 

 Only the species of Bembecia and Weismannia are night-fliers. TheAegeriids can be obtained towards even- 

 ing by sweeping the food-plants or flowers ; towards morning freshly emerged specimens are found sitting on 

 the stalks or stems of the food-plants. 



The Aegeriids closely agree with the Cossidae in the larval habits and the mode of pupation. The 

 larvae only bear a few thin hairs, are bone-yellow or dirty white, with dark brown head and neck-plate, 

 and strong mouth-parts; they have 16 legs, the 10 abdominal ones bearing complete rings of claws. They 

 hibernate twice or only once and live in the interior of stems and branches of trees and shrubs, or in roots, 

 more rarely in the stalks of herbage. They pupate in a cocoon formed of fragments of gnawed wood or in the 

 end-portion of its tunnel. The pupae slender, with very diverse frontal processes, the abdomen bearing belts 

 of spikes; the anal end rounded or tnnicate and bearing a ring of 6 — 12 small hooks or spikes, with the 

 helf of which the pupae usually crawl half out of the cocoon shortly before the moth emerges. The cases of the 

 appendages of the pupa are separate from the body after the moth has emerged. Some species of Dipsosphecia 

 and Chamaesphecia make tubular webs at the root, in which the larva and piipa move up or down according 

 to the degree of moisture. The moths are excellent fliers and are comparatively rarely caught, as they very 

 closely resemble Hymenoptera on the wing; it is therefore advisable to hunt for the hibernated larvae or 

 chrysalisses and to search especially for those species whose life-history is still entirely unknown; the moth 

 is usually found resting on the food-plant or in its neighbourhood. 



As regards the nomenclature of the family it is necessary to state that according to the current rules 

 of Nomenclature the name of Sesia F. \111 (t^-pe: the Sphingid tantalus) is no more available in this family 

 than Trochilium Scop. 1777 (a nomen nudum). Laspeyres enumerates in his "Sesiae Europae" in 1801 no less 



