Merodon. 477 



at all events on the anterior legs. Glaws and pulvilli large and strong; 

 empodium small, bristle-shaped. Wings with a venation about as in 

 Helophilus, but the subcostal cell more widely open, the radial vein 

 ending in the middle between the subcostal and cubital veins; anal 

 vein not dipped downwards; the base of the radial vein with fine 

 bristles. Vena spuria almost not produced beyond the medial cross- 

 vein. Stigma consisting only of the stigmatical cross-vein. Thoracai 

 squamula with long, branched hairs, alar squamula with shorter, flattened 

 hairs. Plumula somewhat short, with simple, not branched hairs. 



The developmental stages are rather well known because a 

 species [equestris, perhaps also other species) is injurious to Narcissus. 

 Already Reaumur (Mém. Ins. IV, 1738, 497, PL 34, fig. 1—12) men- 

 tions and figures a species, generally considered as M. davipes but 

 perhaps more probably equestris; he had got the larvæ in bulbs of 

 Narcissus in November, and the imagines developed the next April. 

 Van Roser (Wiirttemb. Gorr. Blått. 11, 1834) and Serville et St. Fargeau 

 (Encycl. Méthod. X, 1825, 525) mention the same, The larva and pupa 

 of M. equestris (narcissi) are described and figured by Bouché (Naturg. 

 Ins. I, 1834, 52, Tab. V, Fig. 7—13 et Stett. ent. Zeitg. VI, 1845, 150) 

 from bulbs of Narcissus niveus. Resides other papers, often appearing 

 in gardening and agricultural papers, there is an elaborate monograph 

 by Ritzema Bos (Arch. du Mus. Teyler, 2, II, 1885) with some biblio- 

 graphy of the subject. Verrall records (Brit. Fl. VIII, 1901, 559) several 

 samples of its breeding and its damages in England, and Stickel (Berl. 

 Ent. Zeitschr. LUI, 1908, 202) mentions the larva in bulbs of Amaryllis 

 vittata in autumn, they pupated in the earth and the pupa hibernated. 

 — The larva is not of the rat-tailed type; according to the descrip- 

 tions it is somewhat similar to a Si/rphus-larvR, the body is elongated 

 elliptical, somewhat flattened, especially below, of greyish yellow colour; 

 it is evenly attenuated towards the anteiior end, more abruptly behind; 

 it is transversely corrugated, densely beset with fine hairs, among which 

 some stronger. There are distinct mouth hooks and the usual antenna- 

 like papillæ ; on prothorax are the small anterior spiracular processes ; 

 above on the last segment is a short, black posterior spiracular pro- 

 cess, and to each side of it is a pointed process or wart. The length 

 is 16 — 23 mm. The pupa is darker, for the rest similar to a con- 

 tracted larva; it has prothoracal spiracular tubes, directed forwards 

 and diverging; the length is about 14 mm. As far as is known the 

 female deposits the eggs on the ground at the food-plant ; the larvæ 

 live in and devour the bulbs of Narcissus and bulbs of other allied 

 piants; there is only one, sometimes two larvæ in each bulb; the 

 larva is fuU grown in autumn, and it seems to hibernate and pupate 



