132 MOSQUITOES OF NORTH AMERICA 
Scott, Arkansas, has observed the same habit in Megarhinus septentrionalis. 
He took a large number of males of this species upon a certain vine of poison ivy 
(Rhus toxicodendron) and always upon this one plant ; none could be found else- 
where. Such bushes are undoubtedly places of rendezvous in connection with 
the mating-habit. 
Many species of Culicide, on account of their specialized mating-habits, can 
not be bred in captivity. The yellow-fever mosquito, the mating-habits of which 
are discussed in another chapter (p. 275), can be bred successfully for a num- 
ber of generations in comparatively small receptacles. Dr. Dyar has bred two 
generations of Aédes atropalpus in a quart jar containing a small quantity of 
water. 
ABUNDANCE OF MOSQUITOES. 
In our treatment of the subjects of the migrations of mosquitoes, of their 
carriage by wind, of far northern mosquitoes, and of early accounts of mos- 
quitoes, we give many instances of mosquito abundance, and there will be men- 
tioned here only certain recent observations. We have just discussed how at 
times mosquitoes may be found gathered in concrete swarms for sexual purposes 
and these swarms are appropriately considered under mating-habits, In so far, 
however, as they are an indication of unusual abundance of mosquitoes they may 
be mentioned here. 
Theobald briefly describes a few swarms, probably of this character, as follows: 
“ Occasionally cloud-like masses of various Culices are seen. I remember 
twice having noticed dense swarms of them in the fens; in both cases the in- 
sects were male and female C. cantans. So abundant were they that the air was 
quite darkened by them. These insect-clouds were constantly moving up and 
down about ten to twelve feet above the ground. At times the noise they pro- 
duced could be heard a quarter of a mile off, then it would suddenly cease for 
some time and commence again. 
“Mr. W. W. Smith records a case in New Zealand where ‘a train passed 
through a wall of mosquitoes three-quarters of a mile in length, twenty feet high, 
and eighteen inches thick.’ This abnormal swarm was composed of Culex 
(Uranotenia) argyropus Walker. 
* * %* * * * R * 
“ During the present year I had reported that dense masses of gnats were seen 
along the Downs near Wye, appearing like columns of smoke in the valley, 
rising and falling. I did not see this, but visited the Down-sides the next day 
and found great numbers of male C. pipiens about in the evening, dancing in 
little clouds where they were sheltered from the wind.” 
“Romolo Gessi Pascha, in his book ‘Seven Years in the Soudan,’ p. 47 
(1892), speaks of ‘ myriads of mosquitoes which obscured the air’ at Meshra-el- 
Rek. If we go to the Arctic regions we get similar phenomena, for Dr. Lugger 
informs Professor Howard that Dr. Emile Bessels, of the Polaris Expedition, 
was obliged to interrupt his work in Davis Straits (latitude 72° N.) on account 
of the multitude of mosquitoes.” 
The above notes on Culex pipiens clearly refer to swarms of males such as 
have been described under mating habits. This may also be the case with the 
above-mentioned swarms of Aédes cantans and Uranotenia argyropus, but there 
