54 • PIERIDAE. By J. Robee. 



Sexual dimorphism is well developed in many species from all the faunistic regions, seasonal dimor- 

 phism naturally only in those species which inhal^it districts with sharply marked seasonal changes. 



Antennae of varying lengths, e. g. in L/'pfldia rather short, in the South American genus Lepto- 

 ■nhohia on the contrary very long, the club clearly defined or gradually thickened. Forelegs normally deve- 

 loped, therefore capable of use, with bifid claws. Proboscis well developed. Tiie buttertlies feed at flowers 

 and moist places on the ground. Palpi well developed, but variable. Male secondary sexual characters 

 (seent-organs) occur in the species of several genera, e. g. in CoUas as a specially scaled spot on the hindwing, 

 in Catopsilia as broad patches of thick scaling, in Appias (TacJujrk) as a pencil on tlie underside of the ab- 

 domen, in Dhmorphia as large chalky spots of scales on the under surface of the forewing, from which the 

 scent is given off by rubbing against the strongly widened anterior part of the hindwing. Other species 

 (e. g. Pieris hrassicae and its aUies) possess feather-brush scales (Aurivillius) , which are extended over the 

 greater part of the wing and apparently are the cause of the suppression of the dark markings in the d'cf, 

 and other species again" (e. g. Pkris buniae from South America) broad stripes of thick chalky scales along 

 the veins. 



The Pierids — like most lihopalorera — are sun-loving insects, but, in common with a few other 

 butterflies (mostly Satyrids), nevertheless extend into the Arctic, Antarctic and Alpine regions, without losing 

 anvthuio- in brilhancy of colouring in comparison with allied genera from warmer districts. The high moun- 

 tains of South America and the south-eastern boundary of the Palaearctic Region each even possess two 

 genera quite pecuhar to themselves, namely the former Philia with about six species and Andina with 

 one Cofos-Hke species, and the latter Mesapia and Baltia, of which the last-named is very nearly allied 

 to Phnlia. 



The Pierids are as a rule moderate fliers, but some also fly unusually swiftly (Appias) and others 

 so slowly that they can be caught with the hand when on the wing (Lciicidia). They occur in one or 

 more generations. 



The intellect is obviously very different in the various Pierids, for whilst for instance Pieris hnissirdc 

 and the CoZ/as-species are capable of very quickly recognising danger when pursued by the collector', this 

 is much less to be observed in others {Pieris napi and rapae). 



The swarming and migration of the l)utterflies, already referred to, have been regaided i\s nuptial 

 flights; Gatopsihas and Pieris brassicae especially have been observed to form such swarms. 



The eggs are oblong, are laid in an upi'ight position singly or in clusters, sometimes in large num- 

 bers, on the underside of the leaves of the food-plant, aiid are of different colours. 



The larvae are cyhndrical, mostly of green or greenish ground-colour with light hmgitudinal stripes 

 and short hairs; none have yet been observed with spiny or such like processes. They do not possess the 

 fork on the neck characteristic of the Papilionid larvae , which is said to afford the insects protection from 

 their enemies by the emission of an unpleasant odour, neither has it been proved that — like many Papi- 

 lionid larvae — they acquire poisonous or at least nauseous properties from their food; nevertheless they 

 are not only unpalatable to birds, but is has also been observed that fowls which had been fed on these 

 larvae died, evidently in consequence of a poison contained in their bodies. They live on \'arious shrubs 

 and herbaceous plants, such as Papilionaceae, Mimosas, Grucifers and Gaparideae. 



The pupa is attached to plants etc., by its abdomen, in an upright or hanging position, and is held 

 in this position by a girth. Some are of very singular form, such as the tube-shaped pupae of the species 

 of Anthocharis ; but in general the Pierid pupae show few differences. The Palaearctic Zcc/ris euphnnc — 

 and probably not only the other Palaearctic species {Z. fmisti), but also the North American Z. oJijtiipid — 

 pupates in a rather thick cocoon, but still possesses a remnant of the girth. This characteristic (recalling the 

 »Bombycids«) is much more pronounced in the Mexican Enchrira socialis. The larvae of this species are 

 gregarious and go out at night in a procession to feed. The common web hangs down from a bough, iu 

 the form of a pouch ; the pupae are fastened in it head downwards (J. Aleman). 



Some of the Pierids hibernate as pupae, some as larvae, and some — e. g. the Palaearctic (roiicp- 

 ^e>7/,r-species — as butterflies. 



In the Palaeartic and Nearctic Regions the Pierids preponderate by their great numl)ei' of iiulivi- 

 duals, in the tropics they are more restricted. Some Pierids have a very extensive range, thus f'irris ntpar 

 and napi occur in the whole Palaearctic and the Nearctic Regions, Bclonois iDcsciitiiia in the soulliein 

 Palaearctic, Indian and African Regions. 



Although — as already mentioned — the larvae do not ajipear to absorb poison from their food- 

 plants, the butterflies are very little pursued by the birds, and are therefore apparently unpalatable to them 

 or at least not much appreciated. 



Several fossil Pierids have been found, which do not differ in size from the present-ilay sjiecies. 



