SEASONS OF INSECTS. 525 



and amongst the moths, Plusia Gamma, the Phytometrce 

 solares of Ha worth a , and some others. Numberless Co- 

 leoptera belong to this section. The Donacice fly only 

 when the sun is out and the air is warm ; they are then 

 extremely agile and difficult to take. Some Hoplice 

 swarm in the day before noon, and then disappear b : 

 most of the tetramerous beetles also appear to be diur- 

 nal. The Libellulina and many other Neuroptera may 

 also be so termed; and the Hymenoptera almost uni- 

 versally, with the sole exception of the Formicida*. 

 Amongst the Diptera, if we leave out the Tipularice, the 

 rest will be found for the most part to belong to the pre- 

 sent section. 



ii. Crepuscular insects, strictly speaking, are those that 

 appear only during the twilight, whether in the morning 

 or evening; but the term may be understood, with some 

 latitude, to signify all those insects that are seen only in 

 the morning and evening, though after sunrise and before 

 sunset. Of these, some come forth only in the morning, 

 others only in the evening, and others both morning and 

 evening. My memory only furnishes me with a single 

 instance of an insect whose principal appearance and 

 flight are in the morning. Catocala nupta I have often 

 seen flying at this time, about six or seven o'clock, and 

 never at any other: I am not however prepared to assert 

 that it does not appear in the evening or night, but I 

 have then never met with it. In the evening more par- 

 ticularly you hear the hum of the dung-beetle (Geo- 

 trupes), which Linne thought the prognostic of a follow- 

 ing fine day ; and of the swarms of Melolontha vulgaris 



a Lepidopt. Sritann. 263. b Linn. Trans, v. 250. 



c VOL. II. p. 95. 



