MOSQUITOS OF THE PALAE ARCTIC REGION. 323 



The species is so abundant in many parts of Europe as to constitute a serious 

 plague ; so much so that, according to Eckstein and others, agricultural work in some 

 districts has to be carried on by night and cattle stalled during the day, owing to the 

 attacks which A. vexans makes by day on the men and cattle. 



The larva occurs characteristically in flooded meadows, and several generations 

 are passed through in the year. There is very little difference between the larva 

 and those of some species of Ochlerotatus which have detached teeth at the end of 

 the pecten, even the distinctions given in the key being somewhat doubtful. Accord- 

 ing to the figure and description in Howard, byar and Knab's monograph (where 

 the species is named A. sylvestris, Theo.), the siphonal tuft is situated in the middle, 

 though according to Schneider and Martini it is placed well beyond the middle. 

 The only larvae I have seen are from Ceylon, and these agree entirely with 

 Martini's description ; I suspect therefore that the American description may be in 

 error, as there is certainly no difference in the adults. 



Distribution. — Apart from the domestic species {Culex pipicns, C. fatigans and 

 Aedes argentcus), this is the most widely spread of all mosquitos, occurring practically 

 throughout the Palaearctic, Oriental and Nearctic regions. Possibly it may have 

 had its origin in tropical Africa, where there are a number of related forms, but if 

 so its apparent absence from that region at the present time is remarkable. It is 

 common throughout central Europe, perhaps less so in the south, and certainly rare 

 in the north. Some fresh records are : Sweden (Oeland L, Boheman) ; Finland 

 (Helsingfors, Frey ; Tvarminno, Levander) ; Italy (Susa, Sondrio, Torino, Macerata, 

 Chivasso, Bezzi) '; Asia Minor (Konia, Naday) ; Transcaspia (Tashkent, Aschabad, 

 C. A linger) ; Ussuri (Spasskaja, Wuorentaiis) ; Persia (Enzeli, Buxton) ; Korea 

 (Yamada) ; Aden (Kazan Chand, per Capt. P. J. Barraud). 



The variety nipponii occurs in China and Japan, also the Amur region (Ussuri, 

 Spasskaja. Wuorentaus). 



Subgenus Aedes, Mg. 



Adult. Proboscis (in the Palaearctic species) about equal in length to the front 

 femora, or slightly shorter. Palpi very short in both sexes. Antennae of the male 

 with the hair-whorls evenly spread all round the joints. Vertex with broad flat 

 scales, leaving only a small patch of narrow ones on the nape. Lower mesepimeral 

 bristles absent. Male hypopygium with the claspers deeply bitid, without terminal 

 claw, inserted before the tip of the side-piece ; the latter with small hairy basal lobes. 

 Aedoeagus with the parameres indistinct, almost membranous, the mesosome 

 chitinised in two lateral halves, which are split into rather numerous small spines ; 

 one very much larger spine is apically directed. Female cerci moderately elongate ; 

 eighth segment rather large. Front and middle claws of female toothed. 



Larva. Antennae rather long, with numerous spinules and well-developed 

 tuft. Frontal hairs not one in front of the other, as in Ochlerotatus, but almost side 

 by side (in Lang's terminology, the three post-antennal hairs are almost in one line, 

 the middle one not chsplaced). The median anterior thoracic tufts are absent. 



34. Aedes (Aedes) cinereus, Mg. 



Aedes cinereus, Meigen, Syst. Beschr. i, p. 13 (1818). 



Aedes rufus, Gimmerthal, Bull. Soc. Imp. Nat. Moscou, xviii, p. 295 (1845). 

 Aedes leucopvgus. Eysell, Abh. Ver. Naturk. Kassel, xlviii, p. 285 (1903). 

 Culex nigritulus, Zetterstedt, Dipt. Scand. ix, p. 3459 (1850). 

 Aedes fuscus, Osten-Sacken, Bull. U.S. Geol. Surv. iii, p. 191 (1877). 

 ? Culex ciliaris, Linnaeus, Syst. Nat. Ed. xii, i, p. 1002 (1767). 

 This species need not be confused with any other in the Palaearctic fauna. The 

 mostly flat-scaled head, extremely short palpi of the male, reddish, unmarked thorax. 



