October, 1871.] 97 
ON INVOLUNTARY MIGRATION IN INSECTS. 
BY F. BUCHANAN WHITE, M.D. 
In the second part of the Transactions of the Entomological So- 
ciety for 1871, Mr. Albert Miiller gives an interesting paper on the 
effects of atmospheric agencies in the dispersal of non-migratory insects, 
and brings together many records of insects having been found on Alpine 
snow, which he aptly terms the wreck-chart of the * smosphere, “spread 
out for those who will read it.” 
I have lately had an opportunity of studying some cases of in- 
. voluntary migration of insects through atmospheric agencies. One, in 
which the migration had just taken place, and in which the result, at 
least of the majority of insects that fell under observation, was death ; 
and another, in which the migration seems to have taken place at a 
more distant period, and in which the result would appear to have been 
an alteration in the habitat, food plant and habits of the insects. 
The first case came under the observation of Dr. Sharp and my- 
self, during a recent visit to Benmucdhu. Near the summit of that 
mountain, and at about 4,000 feet elevation, were some large patches of 
snow, which, on examination, were found to be thickly strewn with in- 
sects, no less than six orders being represented. It is worthy of note 
that none of the hill-insects proper were found, though both Anarta 
melanopa and Psodos coracina occurred on the mountain—the former 
both at a greater, and at a less, elevation than the snow fields. 
Probably, to use Dr. Sharp’s words, they knew better; that is to 
say, they, by their habits, guard against any involuntary migration, by 
sheltering themselves from the wind under the rocks and stones. That 
Psodos is especially cautious we saw, on a windy day, on another hill, 
where, though the moth was tolerably common, not a specimen could 
be seen, except by turning over stones, under which the insects had 
taken refuge. 
Beforep assing on to the second case, I shall briefly notice the 
principal insects found by us on the snow fields. 
In Coleoptera: Notiophilus biguttatus, Acidota crenata, not uncom- 
mon; these two alone of all the insects were at all lively. Bryoporus 
rugipennis, Arpedium brachypterum, Oxytelus tetracarinatus, Homalota ere- 
mita, Mycetoporus tenuis(?), Philonthus marginatus, Salpingus ater, Hylastes. 
ater, Hylurgus piniperda, Telephorus elongatus, Sericosomus brunneus, Apho- 
dius lapponum, Coccinella ocellata, obliterata, hieroglyphica (in great 
abundance, and an entirely black variety not common), and variabilis. 
In Hymenoptera: a species of Nematus, and several Ichneumons. 
