PIERIDAE. Bv J. RbBER. 53 



2. Family: Pierldae, Whites. 



In comparison with the other faunistic regions, America shows a great abundance of genera. Of the 

 4-0 odd genera of Pierids represented in this region 28 have no representatives in other regions, whilst of 

 the 23 Palaearctic genera only 12, of the 14 Indo-Aiistrahan only 4 and of the 13 African genera also only 

 4 are not represented in other faunistic regions. The American Pierid-fauna has consequently quite a cha- 

 racter of its own, so much the more as several of the endemic genera are very rich in species and the 

 species for the most part show a great abundance of individuals. Of the 28 American genera only one 

 (Neophasia) is confined to North America (accepting the Tropic of Cancer as its southern boundary), and 

 even this wears the garb of allied Palaearctic and Nearctic members of this family, whilst the remaining 27 

 genera ai-e indigenous to South America. Of these again 3 genera inhabit exclusivel}' the high mountain 

 ranges, 1 genus (Tatochihi) is principally met with in the southernmost part of the continent and 2 genera 

 (Sphaeno(fO)ia and Enantia) are island-dwellers. North America is relatively poor in species of Pierids, since 

 it only possesses about 50, the Palaearctic Region on the contraiy showing about three times as many. The 

 whole of the genera which are represented in North America, but yet are not peculiar to this region, occur 

 also in the Palaearctic Region, with one exception (Nathalis). 



Although the great majority of the American species only belong to the medium -sized butterflies, 

 yet the genera Catopsilia , Amijnthia and Gonepterux show also species which are not inferior in size to the 

 largest forms of this family from other regions. Though there is no large number of species in America 

 which equal in the beaut}' of the colour of the wings especialty Oriental Pierids , the American Region is 

 not wanting in strikingly beautiful forms. 



Whilst the other faunistic regions can onlj' show a very small number of Pierid-species which pass 

 as so-called mimics (species of Pareronhi), tropical and subtropical America possesses a great abundance of 

 them, as for example numerous species of the genera Dismorphia, Pereute and Archonias, which show so- 

 called mimicry in both sexes, whilst in the genus Perrhyhris only the ?? of some species exhibit this con- 

 vergent development, the cfcf of only a few species having on the underside indications of a resemblance 

 to protected species of other famihes. Not only these, however, but also species of the genera Pieris, Tato- 

 chihi, Dismorphia , Pereute, Hesperocharis , Appias, Terias, Catopsilia, Euchloe, Anthocharis etc., show striking 

 sexual dimorphism. Seasonal forms occur in North America much as in the Palaearctic Region, in the tro- 

 pical part of South America on the contrary they are practically non-existent on account of the want of 

 sesonal changes. Sharply defined local forms could only be developed to a very small extent owing to the 

 geographical conditions of the region ; on the other hand the high mountain-ranges of South America show 

 a fauna of their own, whilst the large steppe-district in the most southerly part has some forms in common 

 with the south of North America as well as a few endemic ones. 



Most of the American Pierids are not rare , many are even very common , although in comparison 

 with the richness in species and individuals of some other families of Lepidoptera they are not so conspi- 

 cuous as in the Palaearctic Region. Frequently large swarms of different species have been observed, even 

 of such as are by no means of common occurrence. Thus among others at the beginning of October 1874 

 on the Bermuda Islands an immense swarm of Terias lisa was observed, thousands of which fell victims to 

 the birds ; these smaU butterflies flew further westward and had to travel about 600 miles to the next 

 resting-place (Cape Hatteras). The lar\'ae of some species of Pierids on account of their abundant occur- 

 rence do serious damage to field and garden plants both in North and in tropical America; the north of the 

 United States has a dangerous enemy to the pine-forests in Neopliasia menapia, and Pieris rapae, which was 

 introduced into North America about 1860, has increased to such an extent that it does even greater damage 

 there than in its original habitat, the Palaearctic Region. 



In general the Pierids are of medium size, but some species are large butterflies. The main cha- 

 racter of the pattern consists in white colouring with dark , blackish stripes and spots ; yet there are also, 

 particularly among the Exotics, a large number of species which in the size of the wings and the gorgeous- 

 ness of the colours equal the most beautiful forms of other families of Lepidoptera. In these brightly 

 coloured species the contrast between upper and under surface is very striking. Whilst a large part of the 

 species have on the whole the characteristic marking of the family (white-black) , there are among the tro- 

 pical species also many with yellow, blue, red or black ground-colour on the upperside, and on the other 

 hand some with white upper, but variegated under surface. Thus the South American Pereute-sjiecies, with 

 their black ground-colour and red bands on the forewing both above and beneath, completely belie their 

 Pierid nature, and Arckmiias critias and allied species resemble the species of the aeneas-grou]) of the South 

 American Papilios. 



