636 Dr. G. B. LongstafF's Bionomic Notes on BiUterfiies. 



another important factor. Hence it follows that hasty 

 generalisations based on the most accurately recorded 

 observations may be most misleading if the qualifying 

 circumstances be left out of account. 



The first fact that I would emphasise is the rapid flight 

 of the Whites and Yellows,* That Pierines may be seen 

 fluttering slowly about flowers is true enough, — e.g. that 

 Colias cdusa is not always difficult to catch. Nevertheless 

 Pierines have a knack of flying straight on, as if bound to 

 reach some distant place at a definite time, in a way that 

 Satyrines certainly are not given to. Again, though the 

 Nymphaline may go off at a great pace for a short dis- 

 tance, it usually soon returns to its beat. Among many 

 swiftly flying Pierines that I have come across, are : — 

 Catopsilia and the allied genera Callidryas'\ and Gone- 

 jpteryx ; the Neotropical Ghdophrissa drusilla, Cram., and 

 more especially Pieris phileta, Fabr. ;j: ; the powerful 

 Oriental Hehomoia § ; again Ixias pyrene, Linn.,|| though 

 not equal to the last named, is a swift flier, as are also many 

 of the Teracoli, notably the South African 2\ eris, Klug.H 



Commander J. J. Walker, R.N., writing of Euchloe 

 helemia, Esp., at Gibraltar, Tangier, etc., said: "It has a 

 very strong, swift, and erratic flight, and is by no means 

 easy to catcli." ** Even the little Terias, which seems to 

 go slowly, will be found to move so fast that a large pro- 

 portion get away, though in this instance the mode of 

 escape is commonly to dart downwards so that the net 

 passes over it, and to the annoyance of the collector the 

 fly rises from the ground. tt There seems to me to be 

 practically no doubt that the swift flight of the Whites and 

 Yellows is due to their exceptional conspicuousness as com- 

 pared with other butterflies. That they are exceptionally 

 conspicuous is obvious enough. 



But not all Pierines are rapid fliers ; there are marked 

 and significant exceptions. Thus, many years ago, Mr. 

 A. R. Wallace,j| writing of the Oriental genus Thyca 

 {Delias), said : " They have a very slow and weak mode of 



* Trans. Ent. Soc. Lond., 1905, pp. 67, 75, 76, 112- 



t Ibid. 1908, p. 55. 



X Ibid. 1908, p. 49. 



§ Ibid. 1905, pp. 116, 126, and subsequent experience in Ceylon, 



II Ibid. 1905, p. 79. Also MS. notes m Ceylon, 1908. 



1 Ibid. 1907, p. 352. ** Ibid. 1907, p. 48. 



tt Ibid. 1890, p. 369, JJ Ibid. 1865-8, p, 309. 



