96 REPORT UNITED STATES ENTOMOLOGICAL COMMISSION. 
stroy a field of grain, and after they had devoured it, rise again and resume Iheir first 
direction which they had left. 
The species here alluded to is Galoptenus italicm. 
Lallemaut (I. c.) says, in reference to the Algerine species (A. peregri- 
num), that — 
By striking their wings one against another they produce a loud noise resemhling 
that of a swarm of hees when heard at a distance. Gifted with a very strong flight, 
and above all favored by tbe wind, the locusts are able to pass over considerable dis- 
tances without repose. Indeed they have been encountered more than 00 leagues at 
sea, even at the Balearic Isles, and upon the coast of Spain. The hotter the sun the 
stronger and more rapid is their flight. 
He also states further, that if the Sirocco blows and is strong they ap- 
pear to accomplish a journey of 20 leagues in a single day, flyiug fre- 
quently at a very great height. 
The noise made by the locusts of the Old World during flight is 
frequently mentioned by travelers. In addition to what is already men- 
tioned on this subject, we may add that Niebuhr says that " the noise 
they make in flying is frightful and stunning, like that of a waterfall." 
But so far only one correspondent has mentioned anything of the kind 
in reference to our Western locust. 
5. FLIGHTS AT NIGHT. 
That as a general rule swarms alight as night approaches, and wait 
in the morning until the dew is off and the warmth of the sun is felt 
before starting again upon their journey, is so well established in refer- 
ence to locusts in all parts of the world as to need no proof here. But 
that this rule has its exceptions we asserted in our former report and 
gave there some reasons for entertaining this belief. Further investigation 
of this point has served not only to confirm this opinion, but to induce 
us to beheve that the exceptions are much more numerous than we then 
supposed. This fact and the strong probabibty, or, as we think we may 
say, certainty, that swarms frequently are at such a height as to be in- 
visible in daytime, are absolutely necessary to explain some of the 
phenomena of locust movements. We should therefore be led to this 
belief even if we had no direct testimony on these points. 
As we have heretofore seen, the question of nights at night was a 
subject of discussion even in the days of Pliny, who held the affirma- 
tive in opposition to some authors who asserted that they were unable 
to fly at night on account of the cold. This author attempted to prove 
his position, not by any actual observations on the point made by him- 
self or others, but from the supposed fact that locusts passed over the 
Mediterranean Sea from Africa to Italy, and hence, on account of the 
time required, must necessarily fly at night. That he was mistaken in 
reference to the case cited as proof we have already shown, yet we think 
he was correct in his conclusion. 
So far as we have been able to ascertain, this question has received 
