2IO 



CHAPTER II 



per cent 

 SOt 



3 4 



Ballast fauna 

 Coleoptera, 242 species 



DIAGR. 5. Combination of one to six ecological and biological characters (table 6, 

 columns 1-3, 5-7; and p. 209) favouring ballast transport, among 242 species of 

 Coleoptera observed on ballast places in SW England. 



Black = "emigrants" (67 species). White = non-emigrants. 



the ballast-places, all of the 21 "emigrants" but only 81 per cent (51) of the re- 

 maining 62 species combine more than 3 "favourable characters", as shown in 

 diagram 6. 



The estimation of characters favouring ballast-transport was also carried out by 

 comparing the species introduced into Newfoundland with the "non-emigrants" 

 of the English ballast-places. The Carabid and Curculionid families were selected 

 for this purpose. 



Carabidae planti- hygro- saline macro- 



colous philous localities pterous 



Introduced Newfoundland species (23) o 5 = 22% o 14 = 61% 



"Non-emigrants" of ballast-places (63) 3 = 5% 20 = 32% 14 = 23% 46 = 74% 



The difference in the other factors of table 6, as well as in the stage of hiberna- 

 tion, was insignificant in this case. 



Curculionidae planti 



colous 

 Introduced Newfoundland 

 species (29) 15 = 52 % 



"Non-emigrants" of ballast- 

 places (25) 24 = 96 % 



The advantage of a polyphagous choice of food is very striking in this case, and 

 also the predominance of flightless forms among introduced species. 



