39 



are hatched rather late, not before the last part of May; the pools, in which 

 they are hatched, are dried up a fortnight later; the eggs must therefore be laid 

 upon dry land and undoubtedly singly; most likely there is not time for more 

 than one generation; this generation has only one brood, and this brood lives for 

 three or four months. 



In the literature the reports with regard to the life-history are very contradic- 

 tory; GALLI VALERIC and ROCHAZ DE JONGH in Switzerland maintain that they have 

 found hibernating single eggs, attached to fallen leaves in depressions of the ground 

 SCHNEIDER (1914 p. 28) and ECKSTEIN (1919j p. 68 1919 2 p. 100) state that the species 

 has probably "mehrere" generations in the course of the year. For Strassbourg 

 this is also highly probable but for our country this supposition is undoubtedly 

 wrong. SCHNEIDER says that he found the first larvae at Bonn on 1. March; they 

 were newly hatched and pupated already in the course of twelve or sixteen days ; the 

 first imagines arrived on 16. March. He has also found the larvae in the middle of 

 July, and this seems to prove the correctnes of his supposition. In our country 

 where the larvae do not appear before the last part of May, and the ponds nor- 

 mally are dried out before the end of June, more than one generation cannot be 

 the rule. 



With regard to the blood-sucking process THEOBALD contradicts himself. In 

 1901 Vol.' II (p. 225) he implies that probably neither male nor female attack 

 animals or man "as a rule". This supposition is stated by FICALBI, who maintains 

 that they do not attack man or mammalia. On p. 235 in the same volume (1901) 

 THEOBALD says that A. cinereus (female) bites viciously. This last statement is in 

 accordance with that of all observers from recent years. EYSELL (according to 

 SCHNEIDER 1914 p. 26) maintains that it is very bloodthirsty and so does SCHNEIDER 

 (1914 p. 26). He has given a description of the attack of many specimens very 

 like my own. ECKSTEIN says with regard to the neigbourhood of Strassbourg that 

 it "tragt mit einem Hauptheil an der Stechmiickenplage". LANG (1920 p. 80) main- 

 tains "that the general situations, indicated in the British records, suggests that A. 

 cinereus mainly is a river-haunting species". This is by no means in accordance 

 with the observations in our country; it may be found in the forests, along the 

 shores of larger ponds and upon the open plains; I have never seen any special 

 predilection for river valleys. 



Geographical distribution: known in almost all European countries. It 

 is probably identic with Aedes fuscus Osten Sacken North America. 



Genus II. Ochlerotatus. 

 Tab. II. 



1. O. caspius (Pallas). 



Description. Female: Proboscis moderate, subcylindrical, uniform, labellae 

 conically tapered; vestiture of blackish-brown scales intermixed with a few creamy- 



