Journal of
Threatened Taxa | www.threatenedtaxa.org | 26 May 2018 | 10(6):
11815–11817
Natural history of Large Cabbage White Pierisbrassicae nepalensis Gray, 1846 (Lepidoptera: Pieridae) on Nasturtium, Tropaeolummajus (Tropaeolaceae) in Uttarakhand,
India
Bhawana Kapkoti Negi 1 & Ravindra K.
Joshi 2
1 Ministry of Environment Forest and Climate
Change, Indira Paryavan Bhawan,Jor Bagh Road, New Delhi
110003, India
2 G.B. Pant National Institute of Himalayan
Environment and Sustainable Development, Kosi-Katarmal,Almora, Uttarakhand 263643,
India
1 bhawanakapkoti@yahoo.com (corresponding
author),
2 rhinoraboo@yahoo.com
doi: http://doi.org/10.11609/jott.3900.10.6.11815-11817 | ZooBank:urn:lsid:zoobank.org:pub:1605EBE5-93A3-4D35-A453-E9898278C7BC
Editor: George Mathew, (Ex) Emeritus Scientist, KFRI, Peechi, India. Date
of publication: 26 May 2018 (online & print)
Manuscript details: Ms# 3900 | Received 14 November 2017 | Final received 03 May 2018 | Finally
accepted 10 May 2018
Citation: Negi, B.K. & R.K. Joshi (2018).Natural history of Large
Cabbage White Pieris brassicae nepalensis Gray 1846
(Lepidoptera: Pieridae) on Nasturtium, Tropaeolum majus (Tropaeolaceae) in Uttarakhand,
India. Journal
of Threatened Taxa 10(6): 11815–11817; http://doi.org/10.11609/jott.3900.10.6.11815-11817
Copyright: © Negi & Joshi 2018.Creative Commons Attribution 4.0 International License. JoTT allows unrestricted use of this article in any
medium, reproduction and distribution by providing adequate credit to the
authors and the source of publication.
Funding: None.
Competing interests: The authors declare no competing interests.
Acknowledgements: Authors are thankful
to the Director, of the G.B. Pant National Institute of Himalayan Environment
and Sustainable Development, Kosi- Katarmal, Almora (Uttarakhand), India for providing facilities.
Larval
food preferences and various life cycle stages of Pieris brassicae nepalensis, large
cabbage butterfly of the family Pieridae was observed
on Tropaeolum majus,Nasturtium or the Indian Cress, an orange coloured garden ornamental plant,
in Almora District, Uttrakhand.
Pieris brassicae nepalensis belongs to the lepidopteransubfamily, Pierinae, which contains more than 700
species, and is found in a great diversity of colours, with black, yellow,
orange, red bands, streaks or spots. A white butterfly, the nominate species has a wingspan of 65–75 mm. Males have secondary characters and have
specialized scales on the forewing with upper side forewing white with black
apex and no apical dot on the hind wing, whereas there are two discal spots on the forewing with underside hind wing pale
yellow in the female.
The
larval plant of P. brassicae nepalensis,Tropoeolum majus,generally known as Nasturtium is a perennial or annual herb with a climb-ing or twining stem. The alternate, long--stalked leaves are reniformto rounded and entire. The large,
long-stalked, trum-pet-shaped flowers grow from the
leaf axils and remain in bloom from May–October. They are orange, yellow or white,
occasionally scarlet or mahogany red and have a prominent spur. They are
un-scented but produce abundant nectar and are also visited by bees (Volak & Stodola 1998).
Being a
Palaearctic species, the large
Cabbage White is centered largely in the
Mediterranean sub-regions and in the Pamirs, with a
distribution range extending from Baluchistan, Himalaya to Assam and the plains
adjoining the Himalaya. It is one
of the most abundant and commonest butterflies of the Himalaya between
1,000–4000 m (Wynter-Blyth 1957; Mani
1986). Whereas the plant Tropoeolum majus is
a native species of South America, which reached Europe in the 17th century
and other parts of the world thereafter, it has now become a popular garden
ornamental.
The
Large Cabbage Butterfly is essentially diurnal and active when the sun shines
and the temperature is sufficiently high; otherwise, it remains under leaves or
other shelter, its wings erect but with the fore wings hidden from view. Its flight is irregular. They mate during flight, soon after
emergence. The entire host activity
and life cycle (Image 1 A–L), was observed in the month of May 2007, on
nasturtiums, similar activity was also observed in radishes. The egg laying could be most probably
by over-wintered pupae due to prevailing favorableconditions in the Himalayas, for both the host plant and the Large Cabbage
butterfly. The eggs are yellow,
elongated in shape, ribbed lemon yellow and placed one beside the other,
deposited in clusters of 20–100 or more, which is quite greater than
15–20 (Haribal 1992), on the underside of the
leaves of the host nasturtium plant. Embryonic development lasts 6–10 days and soon after larvae crawl
out and start eating leaf epidermis. Its head is black in front, grey at the back, black thoracic plate. Body greyish-green with three longitudinal
yellow lines, numerous bristles and small black spots all over the body and grows
45–50 mm. They first live in
colonies, narrowly grouped one against the other and superficially gnaw the
leaf epidermis. After the second
moult, they scatter into groups of 8–9 individuals. Then they become extremely voracious and
perforate the foliage; eat almost all leaves of the host plant, often leaving
only the large veins. The large
number of larvae and fast feeding by larvae puts tremendous pressure on the
host plant. This particular
phenomenon is very harmful, resulting in high mortality among the growing
larvae, who find themselves with no more food or cover
from the scorching sunlight. Besides, their frass (insect excrement),
thinned out by the rain or dew, accumulates in the heart of the plant rendering
it inedible. Thus, adding extra
pressure on the survival of the remaining growing larvae. The caterpillars develop and then pupate
in June on various supports (walls, roofs, fence posts) most probably as no
cover remains on the host plant for the most vulnerable stage of the butterfly,
the pupae. Pupa is greenish-grey
yellowish or brownish with often three sulphur lines and some parts of abdomen
on the ventral side brownish and wing cases paler, held with a belt-like girdle
of silk, not in a cocoon. Pupation generally lasts for 10–15 days.
The
butterflies appear in July–August and produce a second generation much
more harmful than the first. The caterpillars develop in July–August and
pupate in September, the pupae over-winter. At first glance, it seems the host
activity of the Large Cabbage killed the plant completely but it is observed
that as soon as the weather changed and activities of the Large Cabbage
butterfly diminished considerably, the plant bloomed again with full leaves.
The
butterfly is comparatively stronger in flight than other species of the genus.
It migrates to the adjoining plains in winter, rears a succession of broods
there and returns in May. It is
established that preference for certain plants of the butterfly is based on the
previous experiences rather than on the sense organs or physiological changes,
whereas in the case of females, visual cues such as colour of the plant
determines the suitability for oviposition. The mustard-oil glucosidescontent of the LFPs guides the eating behaviours and turning the larvae
distasteful for many predators. In addition the butterfly also emits an
unpleasant odour and displays warning colouration. Despite such mechanism in place the
different stages of butterflies are relished mainly by insectivorous birds,
insects and occasionally by others.
Globally,
Large Cabbage White is well known as a major crop pest of cruciferous plants,
and can be very detrimental for the produce. The butterfly is relatively less
threatening now due to several measures in place for control, ranging from
natural to chemical ones.
Besides
being considered a major pest, the butterfly was observed to visit several
other crops (apple, lemon, guava, mustard) and wild plants in flowering,
indicating its role in pollination. Its outbreak during the summer usually
coincides with many migrant bird species in the region, thus appears to help in
perpetuating viable population of the birds as well.
The
association between butterflies and plants is highly specific. Truly polyphagousspecies (feed on various unrelated species of plants) are uncommon, but oligophagy (on closely related species) and monophagy (restricted plant species) mark extreme
specialization. This specialization
naturally limits the distribution of butterflies (Mani 1986) as they appear to
be obligatorily bound up with the occurrence of larval food plants (LFP). The diversity of closely related larval
food plant species indicates oligophagy by the large
Cabbage White for oviposition, like cruciferous
plants Brassica, cauliflower, cabbage, turnip, red cabbage, radish of family Brassicaceae and nasturtium of family Tropaeolaceae. Interestingly both the families belong
to the order Brassicales. The Cabbage White Butterfly completes
its life cycle on both cruciferous plants (Brassicaceae)
and on Nasturtium plants (Tropaeolaceae) indicating
extreme specialization of the butterfly between oligophagyand Polyphagy. Belonging to the same order Brassicales,
however, the families suggest similarity in plant chemistry as well. Keeping in view the observations,
possibilities of more LFPS within related families are obvious.
References
Wynter-Blyth, M.A.
(1957). Butterflies of the Indian Region. The Bombay Natural History Society Bombay,
India, 523pp.
Mani, M.S. (1986). Butterflies
of the Himalaya. Oxford and IBH, New Delhi, India, 181pp.
Haribal, M. (1992). The Butterflies of Sikkim Himalaya and
their Natural History. Sikkim Nature Conservation Foundation (SNCF), Gangtok,
Sikkim, India, 217pp.
Volak, J. &
J. Stodola (1998). The Illustrated Book of Herbs. Caxton Edition, London,
256pp.
http://en.wikipedia.org/wiki/Pieris_brassicae