SEASONS OF INSECTS. 523 



winter usually torpid, yet some, as Diurnea Novembris, 

 Cheimatobia brumata, 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 rufa 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 Melolontha 

 vulgar is; 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- 

 mer&i 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 o, fortnight* \ while those 

 which Swammerdam observed did not come forth till 

 the middle of June, 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 



3 Butterfly Collector's Fade Mecum, 66, nctr <>. 

 b De Geer ii. 638. 641. 

 Swamm. Bihl. Nat. i. Conf. 114 with 103. 

 d Reaum. vi. 480 . 



