SEASONS OF INSECTS. 523 
winter usually torpid, — yet some, as Diurnea Novembris, 
Cheimatobia brwnata, and many Tipularia, even then 
make their appearance. 
If you ask, Whether it be not possible to regulate our 
Entomological seasons by the appearance of insects them- 
selves ? I should answer, that probably this might be 
done ; but that further observations seem wanted to en- 
able us to do it satisfactorily. Perhaps the appearance 
of Formica rtifa beginning the business of the year might 
form the commencement of one season ; the flight of the 
orange-tip butterfly {Pontia Cardamines*), of a second; 
a third might be indicated by the swarming of Mclolontha 
vulgaris; a fourth, by that of Amphimalla solstitialis ; and 
the last, by the appearance in numbers of Aphodius cili- 
aris, which in the autumn fills every horse-dropping. 
Some insects are so ephemeral, that they are to be 
found in numbers only for a few days, and then disap- 
pear for that season. Of this description are the Ephe- 
mercc, much of whose history has been detailed to you. 
Those of which De Geer has given an account (E. vul- 
gata) appeared about the end of May or the beginning 
of June, and continued about & fortnight ; while those 
which Swammerdam observed did not come forth till 
the middle of .Tun?, and lasted only three days . The 
same period distinguished those of which Reaumur has 
compiled so interesting a history, but they did not show 
themselves before the middle of August d . My kind 
friend Mr. Marsham not long before his death copied 
a Butterfly Collector's Fade Mecum, 66, note <>. 
" De Geer ii. 638—. 641—. 
c Swamm. Bihl. Nat. i. Conf. 114 with 103. 
d Heaum. vi. 480 — . 
