PIERIDAE. Bv J. RoBEK. 39 



2. Family: Pieridae. 



The Pierids are for the greater part medium-sized butterflies; however, a few Pahiearctic and 

 several Exotic forms are large. The chief character as regai'ds pattern consists in dai'k, blackish, streaks 

 and spots on a white ground, but there are, especially among the Exotics, also a large number of species 

 which rival in size and tlie magnificence of their coloration the most beautiful forms of other families 

 of Butterflies. In these variegated species the upper- and undersides of the wings contrast very strikingly. 

 Whereas our Palaearctic Pierids conform to the colour-character of the family (white and black), we find 

 among the Exotics many species in which the ground-colour of the upperside is yellow, blue, red or black, 

 but also forms with a white upper- and a bright-coloured underside. Thus the Neotropic Pereute-s^edes 

 completely disown their kinship with the cal)bage-whites by the assumption, above and beneath, of a black 

 ground traversed on the forewing by a red band, and ArrJionias erifias and allies resemble the species of 

 the aeneas-gronp of the South American Papilios. The sexual dimorphism is also well developed in many 

 Palaearctic Pierids, seasonal dimorphism being less conspicuous among them. 



Antenna of various length, rather short f. i. in Lcptirlin, and on the contrary very long in the South 

 American genus LcptopJiohia ; the club suddenly or quite gradually incrassate. Foreleg of normal size, fit 

 for use; the claws bifid. Proboscis well developed. The butterthes suck at flowers and on moist places on 

 the ground. Palpus well developed, but of various sizes and shapes. Secondary sexual cf- characters (scent- 

 organs) occur in the species of several genera, f. i. in Cohan as scale-spots on the hindwing, in CutopsUia 

 as broad areas of thick scahng, in Appias (Tachi/ris) as brushes on the underside of the abdomen. The 

 ordinary Palaearctic species of Pkris (bra!<sicae and allies) possess "plume-scales" (Aueivillius), which are 

 distributed over the greater part of the wings and are apparently the cause of the restriction of the dark 

 markings of the o'^cf . 



The Pieridae — like most EhopaJocent — are lovers of sun-shine. They extend, in company with 

 a few Satyrids, farther into the Arctic, Antarctic and Alpine Regions than the other Butterflies without 

 foregoing the brightness of colour as compared with their congeners from warmer cUmes. The high 

 mountains of South America and the south-eastern boundary of the Palaearctic Region are even inhabited 

 each bv two genera entirely confined to them, namely Xi/nipJuiIa with about 6 species and Aiidiiia with a 

 single Co//«.s-like species occurring in South America, and Mrsapin and Haltia found in Asia. 



The Pierids are as a rule moderately good fliers, however some being exceptionally fast (Appias) 

 and others so slow that one ean catch the flying insect with the hand (Leuridia). They have one or 

 several broods. Of certain species, f. i. P. brassicae and some Catop»Uia, it is known that they migrate at 

 times in enormous flocks, which may be considered nuptial swarms. 



The eggs are elongate and of various colours, being deposited end upwards, either singly or in 

 batches on the underside of the leaves of the food-plants. 



The larvae are cylindrical, being mostly of a green or greenish ground-colour ornamented with 

 pale longitudinal stripes and clothed with short hairs; larvae bearing thorn- or such-hke projections have not 

 yet been found in the Palaearctic Region. The forked osmaterium M'hich is found in the neck of the larvae 

 of the PapiJionids and is said to protect the insects In' its nauseous odour against the predations of 

 enemies, does not exist in Pierid larvae, but these are not only unpalatable for birds, but birds have been 

 observed to die from feasting on the caterpiUars of Pierids. They live on various shrubs and herbs, as 

 Papihonaceae, Mimosae, Cruciferae and Capparideae. Some species, by appearing in enormous numbers, 

 become noxious to cultivated plants not only in Europe, as is well known. l)ut also in the Tropics. 



The pupa is fastened by the tail to plants etc., and is either vertical or susjjended, being kept in 

 this position by a girth. Some pupae, f. i. the boot-shaped one of Em-hloi' cdrdamim-s, have a very peculiar 

 shape. The pupa of Zrgrls euphemc, from South Europe and Asia Minor, lies in a rather dense cocoon, 

 having still preserved a remnant of tlie girth. This character, which reminds one of the "Bombycids", is 

 much better developed in the Mexican I-.urhth-a sorialls. The larvae of this species live gregariously and 

 — just like our Thai/Diidojiora-species — march in procession to their food at night. The common bag-like 

 nest of the pupae is suspended from a branch, the pupae being fastened with the head downwards 

 (J. Alejian). 



The Pierids hibernate partly as pupae, partly as larvae, sometimes — f. i. (ronepteri/x rhamni — 

 as imago. 



In the Palaearctic Region the Pierids are predominating on account of their abundance in individuals, 

 being in the Tropics more kept in the background. Some species inhabit a very large area, P. nipae for 

 instance occurring in the wliole Palaearctic and in tlie Nearctic Region, and J', nteseiifiiia in the southern 

 Palaearctic districts, in India and Africa. 



