ALFALFA WEEVIL. 5 
business or social visits to other localities, near or remote. The 
carrying of weevils by these people, even if it be but for a mile or 
two, amounts in the aggregate to a systematic relaying of the species 
over through routes. There seems, in fact, to be a relation between 
the localities where alfalfa from infested fields is carried in this way 
and the country over which the weevils have spread most rapidly. 
No connection, can be traced between the railroads and the actual 
spread of the alfalfa weevil; in fact, the advance of the weevils has 
been rather less rapid along some railroads than in certain regions 
remote from them. The weevils occur rarely in baggage, express, 
and freight cars, and somewhat more often in passenger cars and 
refrigerator cars containing potatoes which have been handled with 
fresh second-crop alfalfa hay. Although there has been a large 
volume of unrestricted passenger traffic from the infested region 
during the past 12 years, no colonization of weevils has resulteds 
and although weevils have traveled in potato cars as far as Denver, 
Colo., Rock Springs, Wyo., and Butte, Mont., and many cars of 
potatoes which doubtless carried weevils were shipped throughout 
the Western States, no colonies have been started by this means. 
The transportation of weevils on railroad trains and wagons is 
little affected by the flying of the species. It seemed reasonable at 
an early period of the investigation to believe that a beetle which 
flies abroad in the summer would alight upon various commodities 
and vehicles and be carried for great distances, but such is not the 
fact. Weevils are rarely found on trains or wagons except in cases 
where new hay is involved.. The flight of the weevil not only plays 
a small part m its distribution by wagons and trains, but it is less 
general and extensive than it was once supposed to be. All records 
which are definite and authentic show only small numbers of the 
weevils in flight at any time. Reports dealing with immense num- 
bers swarming in the air usually mention no specimens at all as 
actually caught, identified, and counted. They do not agree with 
the observations of this bureau, and many of them are probably 
based, by mistake, upon some other insect, such as the dung-beetle, 
Aphodius, which resembles the weevil in appearance and is always 
present im the air in larger numbers than the latter. 
There is no evidence that the weevils ever fly for the purpose of 
seeking fields of alfalfa, either new or previously infested, or to find 
hibernation quarters. The most plausible theory is that their flight 
is caused by a rise in temperature, as are many activities of the lower 
animals. So far as can be learned, this flight is at random. It 
takes some of the weevils into new fields. 
The crawling of the larve is unimportant as a method of spread, 
being limited to a journey of a few feet from one field to another, 
but the crawling of the adults is an important matter. During the 
cold weather of spring and fall a day’s journey of an adult weevil is 
