INTRODUCTION. Ixix 



laria. Independently of the fact that other and better princi- 

 ples of classification have subsequently been employed, it 

 was soon observed that the so-called twilight-flyers are really 

 true Night-Moths, which fly during the whole night, and not at 

 morning and evening twilight only. But in the East Indies 

 we meet with true twilight-fliers, which do not belong to the 

 genus Sphinx^ which Linnaeus considered such, but to the 

 great group of Rhopalocera.* The sun has scarcely set, before 

 we see everywhere, both in Java and Celebes, numbers of the 

 common Melanitis leda. Linn., Amathusia phidippus^ Linn., 

 and Casyupa thrax, Linn., and in Celebes, Debts europa, 

 Fabricius; but I never saw these species wandering about at 

 night in the moonlight, or entering lighted rooms like the true 

 Night-Moths, which are very numerous, although like the latter, 

 they sit still and repose all day, and if disturbed only fly a 

 little way and settle again directly. I have also seen the 

 commonest of these Butterflies, M. leda, flying in abundance 

 in the evening twilight ; and I once observed the same with 

 D. europa. Moreover, I suspect from the exactly similar be- 

 haviour of different species of Mycalesis, and of Elymnias lais 

 Cramer, in the daytime, that these should also be classed 

 among the twilight-fliers in Java. 



" In every country with which I am acquainted, it is well 

 known that many Lepidoptera are very injurious in the larva 

 state, but the perfect insect is considered everywhere to be 

 harmless. I must tell the truth about this, as I have already 

 about their gentleness, and attack their reputation on this 

 point also. In South-west Celebes, a small white Moth, an un- 

 described species of Scirpophaga, is one of the pests of the 

 country. These Moths fly into lighted rooms in the evening 

 in incredible swarms, settle upon everything, including the in- 



* The South American Brassolina (a sub-family of Nymphalida} are 

 also twilight -fliers. 



