ON THE BUTTERFLY FAUNA OF ANDAMAN AND NICOBAR ISLANDS (INDIA). II. PIERIDAE

The present account is a continuation of the first part which deals with family Papilionidae (vide Arora & Nandi, 1980), and based on the material collected by the various parties of Zoological Survey of India as well as on the material already present in the old National Zoological Collections in the Department (abbreviated in the text as N. Z. C), the details of which have been given in the above-mentioned paper. The present paper incorporates 20 species with 27 subspecies distributed over 11 genera under two subfamilies, viz., Pierinae (Leptosia, 1 sp. ; Oepora, 2 spp.; Anapheis, 1 sp.; Appias, 4 spp. ; Saletara, 1 sp. ; lxias, 1 sp.; Hebomoia, 1 sp.; and Valeria, 1 sp.) and Coliadinae (Oatopsilia, 3 spp.; Gandaca, 1 sp.; and Eurema, 4 spp.). Of these, only' three species viz., Anaphei~ aurota aurota (Fabr.), Appias libythea o~ferna Swinhoe and Eurema brigitta rubella (Wallace), all from Nicobars, have been Teported as stragglers to these areas since these have neither been collected recently nor represented in Nt Z. C. However, Oepora neriS8a dapha (Moore) also reported as a straggler to Great Nicobar as been collected more often and is represented here by one example each of male and female. The studies also throw light on the detailed distribution of the Pieridfauna of these areas ; confirm the occurrence of Appias paulina galathea (Felder) in South Andamans, which was hitherto without any authenticated record of this species; and record for the first time the distribution of Ixias pyrene andamana Moore and Oatopsilia florella gnoma (Fabr.), from Car Nicobar. The nomenclature and classification has been mainly followed after Talbot (1939).


INTRODUCTION
The present account is a continuation of the first part which deals with family Papilionidae (vide Arora & Nandi, 1980), and based on the material collected by the various parties of Zoological Survey of India as well as on the material already present in the old National Zoological Collections in the Department (abbreviated in the text as N. Z. C), the details of which have been given in the above-mentioned paper.
The studies also throw light on the detailed distribution of the Pieridfauna of these areas ; confirm the occurrence of Appias paulina galathea (Felder) in South Andamans, which was hitherto without any authenticated record of this species; and record for the first time the distribution of Ixias pyrene andamana Moore and Oatopsilia florella gnoma (Fabr.),from Car Nicobar.
The nomenclature and classification has been mainly followed after Talbot (1939).The Andaman & Nicobar genera belonging to this subfamily can be differentiated by the following key (as adapted from Talbot, loc.cit), Fore wing with vein Rl free.

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4. Fore wing with vein l\Il stalked with the stem of R 4 + 6 and Rs.
Fore wing with vein 1\1:1 below cell angle and arising at junction of discocellulars.
6. Male with a. single tuft of hair arising between 7th-8th abdominal segment.
7. Wings white.Fore wing with vein l\Il nearly from middle of the stem between cen angle and the fork.
Wings yellowish.Fore wing with vein M 1 close to cell angle than to fork.Remarks.-Thissubspecies is close to nina nina, except in the subapical spot being smaller.
2. Cepora nerissa (Fabricius) Talbot (1939) reported as many as four subspecies in the Indian area, including the two from Andaman & Nicobar Islands.Both these subspecies are dealt with here.
The species differs from O. nadina (Lucas) in the black spot in the middle of area above vein CUl.a on underside of fore wing being separate from black border by a white spot.2a.Cepora nerissa dapba (Moore) Distribution.-India: Assam, Nicobars.Also Burma extending to Siam and Malaya.
Remarks.-The species is reported to pe common in Andaman Islands.Remarks.-Thissubspecies is not rare and is restrlcted to Andamans.Th~ other two Indian subspecies, viz., nadina rem,ba (Moore) and nadina nadina (Lucas) are reported from Peninsular India, and Sikkim to Burma, respectively.

Cepora nadina andamana (Swinhoe)
It differs from the preceding species in the black spot in the area above vein CU 1 a on underside of fore wing not being sepa~ate from the black border.
Remarks.-The authors have not s'een any material of the species from Andaman and Nicobar Islands.Bingham (1907) reports a dry season form of the species from Great Nicobar and is of the opinion that the same is a straggler.Probably, the species does not occur in the area.
Distribution.-India: W. Bengal to Assam; Car Nicobar and extending to Burma and Malaya Peninsula.
Remarks.-The subspecies is extremely rare in Car Nicobar.The nominate subspecies is reported to be distributed in Peninsular India.Ferrar (1951) is of the opinion that in Nicobars the Dry Season Forms do not occur normally so that the collection of the males and females of both the forms by the collectors of Ferrar, is considered by the latter as being due to its migration from the mainland.The authors have not seen any material from these areas in N. Z. O.
The species A. libytkea is close to A. lyncida, the hind wing being without a black spot at the end of cell and marginal dots between veins on the underside, but, however, differs in the character of the marginal border (see A. lyncida).

Appias Iyncida (Cramer)
The species is represented by two subspecies viz., nicobarica and galbana from Nicobar Islands and is not reported to occur in Andaman Islands.Both these are dealt with here.
The species differs from libythea.in the hing wing being yellow on underside and the marginal border being broad and dark chocolate, unlike lihythea where it is without the above mentioned border.Remarlcs.-Ofthe .fivesubspecies which are available in the Indian 'region, nicobarica is restricted to the areas as mentioned above and is reported to vary considerably in size and colouration.The material before us also has a male, as small as 48 rom. in expanse as compared with the minimum recorded expanse of 55 mm.(vide Talbot,-1939 andWynter Blyth, 1957 Distribution.-India: Peninsular India to Sikkim and N. E. India; S. Andaman ; Car Nicobar.Also Burma and Sri Lanka. Remarks.-Ferrar (1951) was able to capture this rather rare species in hundreds only in the year 1927 in S. Andanlans, but could get only a pair, or so, after that and has also recorded the subspecies as far as Car Nicobar Island.The material before us for study from N. Z. 0., however, show no other data except the date of registration as '21.4.84' which indicate that the material had been collected even earlier.
A. albina is close to A. paulina, particularly in the marginal black, in males, not being produced.inwardly on upperside fore wing, which has the apex rather acute and with the outer margin curved as compared with the obtuse apex and the straight outer margin in paulina.Remarks.-Talbot (1939) is of the view that there is no authenticated record of galathea from Andamans, and states it to be 'Not rare' in Nicobars.The material present here for study, however, includes a single female from Chiriatapu, which confirms its occurrence in Andamans, though undoubtedly rare as compared with its availability in the areas of Nicobars.Whereas Talbot (1939) reports four female forms of this subspecies, Ferrar (1951) is of the view that there may be as many as six female forms and all of them may occur together.The female forms avai!able for study are mainly referable to f. flava (with upperside yellow, underside with the apical area of forewing yellow) ; f. semiflava (with upperside white and underside with the apical area of fore wing yellow) ; and principalis (with upperside white and underside with the apical area of for~ wing stone white).Remarks.-Thespecies is rare and reported to be restricted to South Nicobar Is. only, particularly Gt.Nicobar and Little Nicobar Islands.The females seem to be quite rare and hitherto only three examples have been reportedly collected by Ferrar (1951).

Saletara panda chrysea Fruhstorfer
Remarks.-The subspecies reported to be restricted to Andaman Island (vide Talbot, 1939) was, l~ter, recorded as very common at Gt. Cocos, an island 20 miles to the North of Gt.Andaman (vide Ferrar, 1951).Now, the single male, recorded from Car Nicobar, extends its distribution further southwards and is of zoogeographic interest.Remarks.-Popularlyknown as 'The Great Orange Tip', because of the characteristic orange patch in the forewing apical area, this subspecies is very common and more closely allied to the mainland subspecies australis than to the nominate one which extends from Nepal to Burma.
Remarks.-This subspecies is close to V. valeria particularly in the fore wings being bluish-green in the males; and without submarginal spots, or smaller if present.However, the females have the narrow submarginal bluish-green spots or streaks unlike those in valeria where these are bluish to white or yellow.

II. Subfamily COLIADINAE
The subfamily Coliadinae is represented by eight species with twelve subspecies distributed over 3 genera, from these areas, and is characterised by the precostal vein on hind wing either being absent or very short and directed basad if present.
The three genera are differentiated by the following key (as adapted from Talbot, 1939) :  Remarlcs.-Thesubspecies is rare and is without any markings on upper side unlike the following two species, viz., pyranthe and florella, where the wings are marked on the upperside.
Although Talbot (1939) records the subspecies from both Andamans and Nicobars, Ferrar (1951)  Distribution.-India,including Andaman Islands, Sri Lanka, Burma extending to Hainan and Taiwan (China) in the South, and Philippines, Borneo, Sulawesi and Java in the East.
Rema1'ks.-Thesubspecies, rare in Andamans, but common elsewhere, closely resembles Gatopsilia crocale as well as florella gnoma except in the forewing marginal markings which are sometimes heavily dusted in Andaman specimens compared with those from Car and Great Nicobars where the marginal markings are comparatively narrow, almost as in the latter species, so that it becomes difficult to differentiate these from each other.Although Talbot (1939) reports the distribution of crocale in Nicobars, there seems to be no authenticated record of the latter there.Instead, following the characters given by Talbot (1939), the present material can be assigned only to pyranthe and florella gnoma both of which occur together.
Accordingly, the subspecies has a wide distribution through S. Andamans, Central and Car Nicobar to the South Nicobar, thus filling the gap in its distribution at least between the mainland and the Indonesian Islands.Remarks.-Therecord of the subspecies from S. Andamans to Great Nicobar, similar to that of pyranthe is interesting in view of being the first authenticated record of the subspecies from areas other than of Andamans.The majority of the specimens, both males as well as females, are invariably with reddish brown markings, though specimens without such markings are not rare but they can be differentiated by the presence of the narrow marginal spots, which are often separate from.each other.
Distribution.-Indiaincluding Nicobar Islands; Sri Lanka, Burma and extending to South China.
Remarks.-Referable to the genus Eurema, the species brigitta, rare in Nicobar but very common elsewhere, is recognised by the complete absence of the discocellular ring spots on the underside of the fore wing; the inner edge of apical black border on the upperside of fore wing being regular and not indented; and the male fore wing being without a sex brand on upper side.There is only a single subspecies with the distribution as above, but it seems to be very rare in Nicobars since it has neither been reported by Ferrar (1951) nor represented in the N. Z. 0., either in old collections or in recent surveys.
18. Eurema bland a (Boisduval) The species is easily distinguishable by' the number of cell spots being three on the underside of fore wing, as compared with generally two in hecabe.However, in the latter one or both the spots may be absent.The species is represented throughout the Andaman & Nicobar Islands.The mainland subspecies blanda silhetana extends right up to Andaman Island; the material viz., blanda moorei from Central & C. Nicobar Island is more closely allied to silhetana than to the southern Nicobar subspecies viz., blanda grisea.All the three subspecies are dealt with here.18a.Eurema blanda silhetana (Wallace) Remarks.-Thissubspecies can very easily be distinguished from the preceding subspecies from Car and Central Nicobar by the marginal band on the upperside of the fore wing being very narrow and reduced, particularly in male.In all the above specimens the three spots in cell of fore wing on the underside are quite prominent which differentiate it from E. hecabe.

Eurema hecabe (Linn.)
This species is widely distributed in India and is represented by as many as five subspecies, of which two viz., blairiana and nicobariensis occur in these islands and are dealt with here.
Pierinae, represented by 12 species with 15•, subspecies distributed over eight genera from Andaman and Nicobar lslands, is characterised by t~e hind wing having a well developed precostal vein which is curved towards distal end and the labial palpi being always hairy.
reports that he had no material from Car Records oj tke Zoological Survey 0/1 Mia Wing expanse.-Male and female, 50-70 mm.