Journal of Threatened Taxa |
www.threatenedtaxa.org | 26 January 2020 | 12(1): 15201–15204
ISSN 0974-7907 (Online) | ISSN 0974-7893
(Print)
doi: https://doi.org/10.11609/jott.5443.12.1.15201-15204
#5443 | Received 02 October 2019 | Final
received 22 December 2019 | Finally accepted 14 January 2020
A first
record of oviposition of Common Onyx Horaga
onyx Moore, 1857 (Insecta: Lepidoptera: Lycaenidae) in Sri Lanka and its importance in conserving a
highly threatened butterfly
Chathura Udayanga
Herath 1, Pavan Bopitiya
Gamage 2, Iroshan Rupasinghe
3 & Moditha Hiranya
Kodikara Arachchi 4
1 Sandanangama, Dunkannawa,
Sri Lanka.
2 Meemanage Watta,
Godagama, Matara, Sri
Lanka.
3 110/D, “Ramani”, Deniyaya Road, Kotapola, Sri
Lanka.
4 42M, Mahaweli Housing Complex, Pallekele, Sri Lanka.
1 chathuraherath1990@gmail.com, 2
pavants.b.g.@gmail.com, 3 jimrupasinghe@gmail.com, 4 meetmoditha@gmail.com
(corresponding author)
Editor: Nancy van der Poorten,
Toronto, Canada. Date of publication: 26 January
2020 (online & print)
Citation: Herath,
C.U., P.B. Gamage, I. Rupasinghe & M.H.K. Arachchi (2020). A first
record of oviposition of Common Onyx Horaga
onyx Moore, 1857 (Insecta: Lepidoptera: Lycaenidae) in Sri Lanka and its importance in conserving a
highly threatened butterfly. Journal of Threatened Taxa 12(1): 15201–15204. https://doi.org/10.11609/jott.5443.12.1.15201-15204
Copyright: © Herath
et al. 2020. Creative Commons Attribution
4.0 International License. JoTT allows unrestricted use, reproduction, and
distribution of this article in any medium by providing adequate credit to the
author(s) and the source of publication.
Funding: Self-funded.
Competing interests: The authors
declare no competing interests.
Acknowledgements: We thank Ms. Chinthani
Malsha Eeriyawala for her
kind support with botanical aspects. We are also thankful to Dr. George Van der Poorten for
his comments to improve this manuscript.
Horaga onyx (Moore 1857) commonly known as
the Common Onyx or Blue Onyx is a Lycaenid butterfly found in Sri Lanka. The Sri Lankan population was described as Horaga onyx cingalensis
by Moore (1884); it is also found in India.
Adult butterflies are very seldom seen, and have been historically
recorded very infrequently and in very low numbers. The biology of this butterfly in Sri Lanka is
unknown and was placed under the Data Deficient category in IUCN Red List in
Sri Lanka in 2007 (IUCN & MOENR 2007).
In 2012 it was declared critically endangered in the National Red List
(MOE 2012).
H. onyx was reported to occur mainly in
the hills, up to an elevation of about 760m (d’Abrera
1998). It has been historically recorded
from Kandy, Rathnapura, Deniyaya, Kottawa
and a few other locations in the Galle District (Ormiston 1924; Woodhouse 1949)
(Figure 1). Recently it was recorded
from the Sinharaja Forest Reserve at Kudawa and Deniyaya (van der Poorten & van der Poorten
2018) and at Pallekele (Moditha
Kodikara Arachchi pers.
obs. 27.vii.2018) (Figure 1). The larval
food plant of H. onyx in India has been recorded as Coriaria
nepalensis (Coriariaceae)
(MacKinnon & de Nicéville 1898;
Chandrasekharan 2019). Glochidion rubrum (Phyllanthaceae)
has been reported as a larval food plant in Taiwan and Litsea rotundiflora (Lauraceae) in Hong Kong (Igarashi & Fukuda 2000). Kasambe (2016)
reported oviposition on Crassocephalum crepioides (Asteraceae) in southern Western Ghats of
India and suggested it being a potential larval food plant. No information on the early stages or
oviposition behavior of H. onyx has been
previously recorded in Sri Lanka, and the observations from this location are
the first.
Observations of the oviposition behavior was recorded using two binoculars; a Bushnell 8x42
and Swarovski 10x56. All images were
taken with a Canon 7D Mark II DSLR camera with 100–400 mm lens.
Observations were carried out at Enasalwatta, situated about 7km (aerial distance) northeast
of Deniyaya Town, in southern Sri Lanka. It is a part of the Sinharaja
Forest Reserve with elevation ranging 800-–1,200 m. Lower montane evergreen forests are observed
in this area (Image 4) with layering of the forest vegetation typical to that
of primary rainforests (Gunatilleke et al.
2008). Average annual rainfall of this
area is 5,000–6,000 mm, with most precipitation during the southwest monsoon
between May and September, followed by the inter-monsoon rains and the
northeast monsoon (Department of Meteorology, Sri Lanka 2019)
On 14 July 2019, a female H.
onyx was observed flying around a Macaranga indica
(Euphorbiaceae) tree in Sinharaja
Forest Reserve at Enasalwatta, Deniyaya,
Sri Lanka (6.3910N & 80.6040E). The elevation of the site is 1,024m. Relative humidity at the time of observation
was around 65% with varying cloud cover of 20–70 %. The observations recorded here were made
adjacent to a stream near a roadside tree that was about six meters in
height. M. indica
Wight, 1852, is native to Sri Lanka, occurring from wet lowlands to montane
forests (Dassanayake 1997) and can be seen regularly
on roadsides and forest edges in this area.
It was identified with its characteristic leaves, which are large, with
slender petioles; 6–18 cm, blades ovate, papery, base broadly rounded and
peltate, apex acute, numerous palmate secondary nerves arising from petiole
insertion, few conspicuous elongate glands on main nerves beside petiole
insertion of which two were most prominent and was used to separate this
species from Macaranga peltata (Euphorbiaceae) which is the only confusion species
and lacks these glands. The tree was at
the flowering stage with its flower panicles formed along the branches.
The butterfly was identified by
its characteristic white band on the underwing which was broad over both fore-
and hind-wings (Image 1), distinguishing it from the similar Brown Onyx (H. albimacula).
Less extensive and less intense blue on upper wings implied that it was
a female (Woodhouse 1949; d’Abrera 1998; van der Poorten & van der Poorten
2018). The butterfly flew around the
periphery of the tree, seldom moving away.
It flew over the entire canopy crown which ranged from three to six
meters high from ground level, but favored the
sun-lit side. It perched on leaves to
sun bathe several times but seldom remained for more than about 40 seconds on a
leaf, before flying off again. In one
instance it flew down and perched briefly on a bush near the ground.
From time to time the female flew
from its perch on to the peduncle of an inflorescence with developing flower
buds. On one occasion, it perched near
the base of the inflorescence, moved to the developing floral buds, curved its
abdomen and placed a single egg on it (Image 2). In some instances, although it flew on to a
branchlet or a flower panicle, no ovipositing was
observed. Just after ovipositing,
the butterfly was seen flying over the canopy and was not seen again on that
day. These observations were made from
12.25h to 12.40h during which time the sky was clear with intermittent clouds;
a slight drizzle occurred in the morning.
The next day, on 15 July 2019, we
observed a female flying around the same tree between 09.20h and 09.30h but
were unable to confirm whether or not it was the same individual seen the day
before. During the short period
observed, it oviposited once. This time the egg was laid directly on a
branchlet, close to a flower panicle (Image 3).
In other respects its behavior was similar to
that seen the day earlier. It appears,
judging from its oviposition behavior and the
location where eggs were laid, that the larvae feed on flowers and flower buds.
The current information obtained
from this site is crucial for gathering further information on the biology of
this species and paves the way to understand its restricted distribution and
scarcity. This is particularly relevant
because of the dearth of information on the biology of the species, which has
been a drawback to the development of a conservation strategy to protect this
highly threatened subspecies. Further, M.
indica must be confirmed as the larval host plant
of this species by rearing larvae to successful emergence of adults. Until such time, the suggested larval food
plant here must be considered tentative, since it is well known that some
species sometimes oviposit on plants that are not used as larval food plants.
For figure
& images - - click here
References
Chandrasekharan, V.K. (2019). Horaga
onyx (Moore,
[1858]) – Common Onyx. In: Kunte, K., S. Sondhi & P. Roy (eds.). Butterflies of India, v. 2.68.
Indian Foundation for Butterflies.
http://www.ifoundbutterflies.org/sp/973/Horaga-onyx. Accessed on 14 December
2019.
d’Abrera, B. (1998). The Butterflies of Ceylon.
WHT, Colombo, 166pp.
Dassanayake, M.D. (eds.) (1997). A Revised Handbook to the
Flora of Ceylon. Vol. 11. Oxford & IBH Publishing Co., New Delhi,
420pp.
Department of Meteorology, Sri
Lanka (2019).
http://www.meteo.gov.lk/index.php?option=com_content&view=article&id=94&Itemid=310&lang=en
Accessed on 31 July 2019.
Gunatilleke, N., R. Pethiyagoda
& S. Gunatilleke (2008). Biodiversity of Sri Lanka.
Journal of the National Science Foundation of Sri Lanka 36 (Special Issue):
25–62. https://doi.org/10.4038/jnsfsr.v36i0.8047
Igarashi, S. & H. Fukuda
(2000). The life
histories of Asian butterflies. Vol. 2. Tokai University Press, Japan,
742pp.
IUCN & MOENR (2007). The 2007 Red List of
Threatened Fauna and Flora of Sri Lanka, Colombo, 148pp.
MOE (2012). The National Red List of
2012; Conservation status of the Fauna and Flora, Ministry of Environment,
Colombo, 452pp.
Jayasinghe, H.D., S.S. Rajapaksha & C. de Alwis
(2014). A
compilation and analysis of food plants utilization of Sri Lankan butterfly
larvae (Papilionoidea). Taprobanica 6(2):
110–131.
Kasambe, R. (2016). Errata: Crassocephalum
crepioides, and not Gnura
cusimbua, possible new larval host plant of the
Common Onyx, Horaga onyx from Southern
Western Ghats, Kerala. Bionotes 18(4): 131.
MacKinnon, W. & L. de Nicéville (1898). A list of the butterflies of Mussoorie in the western Himalayas and neighboring
regions. Part III. Journal of the Bombay Natural History Society 11:
585–605.
Moore, F. (1880–1887). The Lepidoptera of Ceylon,
Vol. 1, 2 & 3. L. Reeve, London. pp.i–xii+1–190,
pp.i–viii+191–353 & pp.i–xv+354–932.
Ormiston, W. (1924). The Butterflies of Sri Lanka,
H.W. Cave & Co.,Colombo, 143pp.
van der Poorten,
G.M & N.E. van der Poorten (2018). Field guide to the
Butterflies of Sri Lanka. Lepodon Books, Toronto,
250pp.
Woodhouse, L.G.O. (1949). The Butterfly Fauna of
Ceylon, 2nd Edition. The Colombo Apothecaries’ Co. Ltd.,
Colombo, 138pp.