1«4 



diminishes and from the latter part of November it is almost impossible to get a 

 single specimen in stables which in Jjjly sheltered thousands of A. maculipennis. 

 The hibernation does not take place in the stables. When studying the hibernation 

 places of C. pipiens I only very rarely found A. maculipennis in them. The number 

 of A. maculipennis which I have seen in human dwellings in winter is also al- 

 ways extremely small; in the district of Silkeborg it has been maintained that the 

 females in late autumn fly into the rooms; otherwise I have never heard anything 

 of this and I take it to be highly improbable that our rooms are the real hiberna- 

 tion places of the species. On the other hand I have myself found the species in 

 small numbers in remarkably cold but always dark localities, especially out-buil- 

 dings. The veterinary surgeon Mr. Petersen has kindly told me that in the western 

 part of Jutland, near Ribe, on the farm Villebol, on 23/n 1917, he found numerous 

 A. maculipennis, hanging under the ceiling of a peat house; it was in company with 

 T. annulata. I suppose that such localities are the real hibernating places, at all 

 events in our country, not the stables. - Most probably this is in accordance with 

 the high temperatures in winter in the stables; low temperatures being a life con- 

 dition for the mosquitoes, as they do not suck blood during winter. 



That the hibernation as a rule does not take place in stables but in out- 

 buildings etc. is corroborated by many other authors. I refer especially to Eckstein 

 (1919m p. o31); Martini (1920!). Also Annett and Dutton (1901 p. 1013) maintain 

 that A. maculipennis hibernates in outbuildings, cellars, dairies;, cheese rooms, pan- 

 tries; lumber rooms, ware houses, coal cellars. The two last named authors state 

 that the mosquitoes were very difficult to rouse during hibernation. How long the 

 mosquitoes remained in the same position during the winter months it was not easy 

 to determine, but it was noticed that many of the Culicida- were wholly or partially 

 enveloped in a thick mould which had grown in and around their bodies thus 

 fixing them in the attitude described. 



3. In my opinion the number of A. maculipennis is greatest in the hog-sties; 

 not so great in the cowhouses and smallest in the horse stables; often the num- 

 ber is also great in the hen-houses. As however the rearing of swine during these 

 last two years has been very greatly diminished, so much so that often there are no 

 hogs at all in the sties, it has been difficult for me to corroborate this supposition. 



It is always so that dark and dirty, badly ventilated stables without draught 

 contain a greater number of A. maculipennis than light, clean, well ventilated stables; 

 newly whitewashed stables always contain only very few specimens. Mr. Kryger 

 as well as myself have observed dark stables were A. maculipennis has been pre- 

 sent in thousands, we are almost inclined to say in millions; when the door lias 

 been opened and we have tried to touch the ceiling with a net, crowds of mosqui- 

 toes have hovered around us. It further seems that the number is greatest in the 

 small stables with low ceilings, it is further greatest in stables with many animals, 

 much smaller in stables with only few cows or horses. The mosquitoes occupy the 

 ceiling more than the walls and always prefer the darkest corner; in particular 



