THYRIS Bv Dr. A. Seitz. 371 



24. Family: Thyrididae. 



This small family, which is represented in the Palearctic Region by some 20 forms, would be better 

 placed with those Lepidoptera which are general^ called Micros. But as in the case of the Sesiidae, we 

 bring them in this volume, which contains the heterogeneous mass of '■Bombyces". They are in fact doubtless 

 nearest related with the Pyrals; but they exhibit also affinities to the Drepanidae. The family contains more 

 than 180 species of very varied facies, belonging to 26 genera, half of which are monotypical. 



The distribution is almost universal, but the tropics and subtropics take the larger share. In the various 

 countries of Europe at most one form occurs, which, moreover, is sporadic, the Thyrididae not at all being 

 represented in many districts of this continent. They are generally not rare where they occur. Some are decided 

 day-fliers, others appear to be on the wing regardless of the time of day. I have observed, e. g., species 

 of Dysodia fly in the hot sunshine and also visit the lamp at night. Some species have almost the habits 

 of Geometridae, resting by day concealed on the underside of leaves and when flushed flying only a few yards 

 before disappearing again in the bushes. The larvae are only known of a few species. The larva of Thyris 

 is common in Central Europe and is remarkable for its bug-like scent. 



Palpi nearly always thin, but different in length. Characteristic is the absence of the maxillary palpi. 

 Proboscis present, usually well-developed and used for sucking. The submedian of the forewing forked, 

 veins 4—8 from apex of cell, 2 — 11 from cell. The wings have frequently an excised or irregular distal mar- 

 gin and sometimes hyaline spots. Moreover, the costal margin of the forewing not rarely is ventricose or bears 

 bladder-like swellings. The antennae are nearly always simple, being rarely shortly pectinated. — The larvae, 

 as far as they are known, live inside the plants or make a protecting hood; they have 16 feet and bear sparse 



hairs. 



The family has been monographed several times, e. g. by A. Pagenstecher and G. H.a.mpsox. 



1. Genus: Thyris Lasf. 



This genus contains 5 very similar forms, which are confined to the temperate districts of the North- 

 ern Hemisphere. Characteristic is the open cell of both wings. The forewings have a curved distal margin 

 and pointed apex, the hindwings are excised below the apex. Across the disc of both wings small hyaline 

 spots. The body robust compared with the small wings, and the abdomen peculiar, appearing suddenly nar- 

 rowed beyond segment 5 with the apex pointed. The larvae are green, bearing sparse minute bristles; they 

 live in a case made of the leaves of the. food-plant and slightly smell like bugs. The moths have one brood 

 and fly in the sunshine, resting on flowers with the wings spread out, particularly on Umbellifers and Scabious. 



T. fenestrella Scop. (= fenestrina Schiff., pyralidiformis Hhn.) (50 e). Dark brown, the wings with fenestrella. 

 blackish reticulation; fore- and hindwing similar in colour, dark brown; scaling of body with a coppery gloss. 

 The hyaline spots rather large, composed of smaller spots, or cordiform. Almost every^vhere in South and Central 

 Europe, but local; in Northern Europe only sporadical, in Holland, Livonia, also in Anterior and Central 

 Asia to Amurland. The green, sparsely hairy, larva on Clematis. Abundant in many localities. — nevadae nevadae. 

 Oberth. (50 e), from Eastern Spain, differs in its paler colouring and the strong reduction of the hyaline spots. 

 This form has been placed by Dyar as a variety with the (entirely different) North American T. htgubris Bdv. ; 

 the latter, however, is much larger, more robust, and deeper black. The South European specimens of fenestrella 

 appear to have always smaller vitreous spots than the Central European ones; at least, the hyaline spots 

 are smaller in the series obtained by me at Genoa than in the examples I have collected in Germany. 



T. diaphana iS^^r. (= vitrinia H.-Schdff. nee Bdv.) (50 e) differs from the preceding sjjecies in the diaphanu. 

 colouring being golden brown instead of black-brown; the h3'aline spots are very small, sometimes disappearing 

 on the forewing, and forming on the hindwing a continous band. — Hitherto only knoAvn from Sicily. 



T. usitata Bull. (50 e) is the East-Asiatic form, which comes very close to fenestrella. Specimens from itsUata. 

 Amurland are not essentially different from European ones according to Staudixger. On the whole the speci- 

 mens are somewhat smaller, with more pointed wmgs and smaller hyaline spots than in Europe. Certainly only 

 a local form of fenestrella. — Widely distributed in Eastern Asia, occurring in China, Japan, Amurland and 

 Corea. 



