310 F. W. EDWARDS. 



16. Acdes (Ochlerotatus) detritus (Hal.) (fig. 7h). 



Culex detritus, Haliday, Entom. Mag. i, p. 151 (1833). 



Culex salinus, Ficalbi, Bull. Soc. Ent. Ital. xxviii, p. 29 (1896). 



Culex terriei, Theobald, Mon. Cul. iii, p. 193 (1903). 



This species is subject to a good deal of variation. Normally the dark parts 

 of the abdomen are speckled over with light scales, but these are sometimes absent. 

 Normally also the male palpi are entirely dark-scaled, but specimens are not 

 infrequently met with in which the long joint bears a good many pale scales on its 

 apical half. When both these variations occur together the specimens are not easy 

 at first sight to distinguish from A. salinellus. Apart from the structure of the 

 male hypopygium, which is of course diagnostic, the best distinctions are to be 

 found in the almost unifomi brown colour of the mesonotal scales of A. detritus, 

 and the row of black spots down the middle of the venter, which are usually 

 conspicuous in living specimens, though they are not so easily seen in the dry. 



So far as known, the larva is confined to salt or brackish water, and, as in many 

 other such forms, the gills are greatly reduced in size. 



Distribution. — European coasts, from Ireland and France to Denmark and 

 Macedonia ; also coasts of North Africa, Suez Canal and Palestine. Apparently 

 does not occur inland in eastern Europe, as do its frequent associates A. caspius 

 and^. dorsalis. I have, however, seen a single male specimen, with a hypopygium 

 identical with that of European A. detritus, from Kashgar, Chinese Turkestan 

 {Racquette, in Stockholm Museum). 



17. Aedes (Ochlerotatus) cataphylla, Dyar, var. rostochiensis, Martini (fig. 7 1). 



Aedes cataphylla, Dyar, Insecutor Inscitiae, iv, p. 86 (1916). 



Aedes prodotes, Dyar, Insecutor Inscitiae, v, p. 118 (1917). 



Aedes rostochiensis. Martini, t)ber Stechmiicken, p. 246, diagnosis only (1920), 

 and Sitzb. u. Abh. natf. Ges. Rostock vii, p. 204 (1920). ' 



This species and A. salinellus are together distinguished by the pale-speckled 

 femora and the more or less conspicuous pale ring towards the end of the long joint 

 of the male palpi ; they differ from A. detritus in never having scattered pale scales 

 on the dark parts of the abdomen, though the eighth segment is generally almost 

 entirely pale. The two species A. cataphylla and A. salinellus are extremely alike ; 

 the most obvious difference in the adult is in the colour of the scales of the proboscis, 

 which in A. cataphylla are almost all black, in A. salinellus extensively pale about 

 the middle, but I am not sure how far this difference is constant. There is a slight 

 but fairly well defined difference in the hypopygia (indicated in the key), but the 

 most striking character of A. cataphylla is the presence of a couple of disconnected 

 spines at the end of the pecten of the larval siphon. 



None of the old European names seem to be applicable to this species, but I am 

 satisfied that it is specifically identical with the western North American A . prodotes, 

 Dyar (which Dyar now recognises to be the same as his previously described 

 A . cataphylla) . The male palpi have the same pale ring ; the larva has the same two 

 detached spines on the pecten, and the hypopygia are identical, except for a slight 

 difference in the size of the apical lobes of the side-pieces. The American specimens, 

 however, are on the average smaller, and the mesonotal scaling is rather different 

 from the usual European type, being rather darker in the middle and with more 

 numerous white scales at the sides. Nevertheless the Norwegian specimens in 

 the British Museum have the sides of the mesonotum even whiter than the 

 American specimens I have examined. 



Distribution. — I have seen male specimens from Denmark {Wesenberg- Lund) ; 

 Sweden (Smaland, Stockholm and Dalecarlia, Boheman) ; Norway (Smaalenene, 



