Journal of Threatened Taxa |
www.threatenedtaxa.org | 26 September 2020 | 12(13): 16861–16867
ISSN 0974-7907 (Online) | ISSN 0974-7893
(Print)
doi: https://doi.org/10.11609/jott.5425.12.13.16861-16867
#5425 | Received 25 September 2019 | Final
received 01 September 2020 | Finally accepted 11 September 2020
A first complete documentation of
the early stages of Hampson’s Hedge Blue Acytolepis
lilacea lilacea Hampson,
1889 (Lepidoptera: Lycaenidae) from Western Ghats,
Kerala, India
V.K. Chandrasekharan 1 & Muhamed Jafer Palot 2
1 Kaniv [Kalathil],
Edakkulam Post, Koyilandy,
Kerala 673306, India.
2 Zoological Survey of India,
Western Regional Centre, Pune, Maharashtra 411044, India.
1 vkchandrasekharanlic@gmail.com, 2
palot.zsi@gmail.com (corresponding author)
Editor: George Mathew, (Ex) Emeritus
Scientist, KFRI, Peechi, India. Date
of publication: 26 September 2020 (online & print)
Citation: Chandrasekharan, V.K. & M.J.
Palot (2020). A first
complete documentation of the early stages of Hampson’s Hedge Blue Acytolepis lilacea lilacea Hampson, 1889 (Lepidoptera: Lycaenidae)
from Western Ghats, Kerala, India. Journal of Threatened Taxa 12(11): 16861–16867. https://doi.org/10.11609/jott.5425.12.13.16861-16867
Copyright: © Chandrasekharan & Palot 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: None.
Competing interests: The authors
declare no competing interests.
Acknowledgements: We are thankful to the principal
chief conservator of forests (Wildlife), Kerala Forests & Wildlife
Department and the wildlife warden, Parambikulam
Tiger Reserve for permission to collect and for the field support. MJP is grateful to the director, Zoological
Survey of India (ZSI), Kolkata and the officer-in-charge, ZSI, WRC, Pune for
facilities and encouragement. We thank
Shri. Balakrishnan Valappil, V.C. Balakrishnan,
Satheesh Pullat, and Vishnu Vijayan (biologist, Parambikulam Tiger Reserve) for their immense support. We are grateful to Shri. Purnendu
Roy and Dr. Milind Bhakare
for their help and guidance in the completion of this paper. We are also thankful to the members of the
Ferns Nature Society, Wayanad and the Malabar Natural History Society,
Kozhikode for their encouragement and support.
Abastract: This is the first complete
documentation of the early stages of Acytolepis
lilacea lilacea,
the subspecies from southern India, with the first record of the larval host
plant Cycas circinalis, and a comparison with
the early stages of Acytolepis puspa felderi Toxopeus, 1927, a sympatric and similar species,
highlighting the notable differences.
The significant differences noted in the early stages of Acytolepis lilacea lilacea with that of A. puspa
are the difference in ornamentation of eggs, more fluffy, blue shaded and less
hairy larvae and more elongated
pupae. No previous record of the
early stages of any of the subspecies of Acytolepis
lilacea Hampson, 1889 is available. Preliminary observations regarding the flight
period and seasonal varriations of Acytolepis lilacea lilacea, from Parambikulam
Tiger Reserve, Kerala, India, are also presented.
Keywords: Acytolepis lilacea
lilacea, Cycas circinalis, early stages, larval host plant, Parambikulam Tiger Reserve, Western Ghats.
Acytolepis Toxopeus,
is a small genus of lycaenid butterflies under the Lycaenopsis
group, represented by five species
in the world, viz: A. puspa (Horsfield, 1828), A. lilacea
(Hampson, 1889), A. najara (Fruhstorfer, 1910), A. ripte
(Druce, 1895), and A. samanga
(Fruhstorfer, 1910).
The first two species are known from India and the others are from the Indomalayan and Australasian realm. Acytolepis
lilacea, Hampson, 1889 (Hampson’s Hedge Blue or
Lilac Hedge Blue) is a lesser known butterfly under the subfamily Polyommatinae of tribe Polyommatini
and has a recorded distribution in southern India, Sri Lanka, Myanmar, Vietnam,
Laos, and Thailand. There are three
subspecies of Acytolepis lilacea in the world.
The distribution record of A.l. lilacea, Hampson, 1889 is from southern India, A.l. moorie, Toxopeus, 1926 is known from Sri Lanka, and A.l. indochinensis,
Eliot & Kawazoe, 1983 is widely distributed in Laos, Vietnam, Myanmar, and
Thailand.
Acytolepis lilacea lilacea
was described by Hampson in 1889 from the southern slopes of Nilgiris (914m), Western Ghats, India as Cynaris puspa var. lilacea.
After this, sometimes it was treated as a separate species (Bingham,
1907; Swinhoe, 1910; Evans 1932) and later as a
subspecies of Acytolepis puspa (Cantlie 1963).
But Eliot & Kawazoe (1983), after detailed work, confirmed its
status as a separate species and also described a new subspecies, A.l. indochinensis
from Laos. The male genitalia of A. lilacea is of the same pattern as A. puspa, but one-third larger (Eliot & Kawazoe
1983). Males have a more rounded apex
and termen than A. puspa
and significantly, the series of post discal striae on the underside of the forewing is more
regular. The subspecies lilacea, which flies in southern India, is distinguished
from other subspecies by the male lacking whitish discal
areas above on the forewing, the hindwing without whitish patches and edging to
the marginal spots, and on underside the forewing postdiscal spot in space 9 is
usually present (Eliot & Kawazoe 1983).
This subspecies is uncommon and only recorded from very few places in
southern India, mainly from Palni Hills, Nilgiris, and Coorg (Larsen 1987). Recently, the taxa has been reported from Neyyar Wildlife Sanctuary (WS) and Parambikkulam
Tiger Reserve (TR) of Kerala (Kunte et al.
2019). Gaonkar
(1996) in his report on butterflies of Western Ghats also recorded the species
from Kerala, Karnataka, and Tamil Nadu.
The species is protected under Schedule II of the Indian Wildlife
(Protection) Act, 1972. Recent work on
the larval host plants of the butterflies of the Western Ghats by Nitin et al.
(2018) has not listed any larval food plant for A. lilacea.
This species is probably often overlooked in
its habitats with the sympatric, similar looking and quite common Acytolepis puspa (Common
Hedge Blue). It occurs with A. puspa in low land forests, penetrating the subtropical
zone, but is very much scarcer. Nothing
has been published so far, concerning the early stages of this speceis anywhere in the world. Here we present, for the first time, the
early stages of Acytolepis lilacea lilacea, recorded
from Parambikulam TR, Western Ghats, Kerala,
India. The recorded early stages, larval
feeding patterns and the recorded host plant show marked differences from those
of A. puspa, and once again confirms the
status of A. lilacea as a distinct species
from A. puspa. We present here the images of egg, final
instar larva, and pupa of both species for comparison (Image 3 & 4).
Materials and methods
During the annual butterfly
survey held in Parambikulam TR, Palakkad District,
Kerala in November 2018, we came across a female A. lilacea
at Anappady area (Image 1), (10.443N &
76.813E) laying eggs on the tender leaves of Cycas circinalis
(Cycadaceae).
We collected the eggs, reared five caterpillars in air-tight transparent
plastic containers by providing fresh leaves of the larval host plant. We photographed all relevant stages of the
life history using a Canon 5D Mark III SLR Camera with a Canon 100mm macro lens
and a Kenko 1.4X Teleconverter. We compared the images of the early stages
with the relevant, previously recorded early stages of A. puspa by VKC.
We analysed the images taken of the adult A. lilacea
lilacea from the reserve during the months from
October to January for seasonal variations and for ascertaining an approximate
period of its flight in the reserve.
Observations and
Results
Larval host plant
The female laid eggs on the
tender leaves of Cycas circinalis, a
gymnosperm, commonly known as the Queen Sago plant (Image 2), having a
distribution in Indo-Malaysia and tropical eastern Africa. The only other butterfly species breeding on Cycas
circinalis in the Western Ghats is Chilades pandava
(Cycad Blue or Plains Cupid), and the larvae of both these species eat up the
tender leaves and damage the plant
considerably. We also searched the
garden variety of Cycas – Cycas revoluta, which
is commonly grown in the garden as an ornamental plant, for the early stages of
A. lilacea, but did not encounter
any. Well-wooded areas with an abundance
of Cycas circinalis appear to be necessary for
the survival of A. lilacea and this may
be one of the reasons for its limited population and distribution compared to
that of A. puspa. Whereas, A. puspa
is widely distributed all over India and its larvae are known to feed on many
plant species, namely, Shorea roxburghii (Dipterocarpaceae),
Cratoxylum cochinchinense
(Hypericaceae), Moullava
spicata, Paracalyx
scariosus, Peltophorum
pterocarpum, Xylia
xylocarpa (Fabaceae), Hiptage
benghalensis, H. madablota (Malpighiaceae),
Bridelia retusa,
B. stipularis (Phyllanthaceae),
Lepisanthes tetraphylla,
Schleichera trijuga,
and S. oleosa (Sapindaceae)
(Nitin et al. 2018).
Early stages
The eggs were laid on the underside
of tender leaf blades of the host plant Cycas circinalis,
mostly one on each blade. The eggs are
white, button-shaped, with irregular tiny projections on the surface. They are similar to the eggs of Chilades pandava
but quiet different from that of A. puspa.
We collected five eggs. Three eggs hatched on the fourth day and two on
the fifth day. The newborn
tiny caterpillars were light yellow with two rows of obscure white spots on the
dorsum, divided by a logitudinal greenish-yellow
line. Caterpillars live on the underside
of the leaf blade, eating up the soft tissues leaving the cuticle. In advanced instars the colour of the
caterpillar on the upperside acquired bluish-green to
rich sky blue shades, while the front, rear and lateral sides remain
yellow. The caterpillar had tiny
tubercles on its body, each of which bears a light yellow hair. The density of these tiny hairs is less
compared to the caterpillars of A. puspa. The pupa was similar in shape to that of A.
puspa, but more elongated. It had thin, tiny hairs all over, and two
rows of black spots on the upper side.
Many pupae were found decorated by black markings. The pupae were held by a body band. The pupa measured 10mm and the adult
butterfly emerged eight days after pupation.
The entire life cycle was completed in 32 days. The adult specimen was deposited at
Zoological Survey of India, Western Ghat
Regional Centre, Kozhikode (Reg. No.
ZSI/WGRC/IR/IV.No. 12859).
Interestingly,
we have not seen any ants attending to the caterpillars found in the
field. Also, in the absence of tender
leaves, the larvae were found to feed on semi-matured and matured leaves. Many pupae found in the field were either
infected by parasites or damaged. This
may be one of the reasons behind the restricted population of this species,
even in its conducive habitats. Also, it
was observed that the deeply coloured larvae found were those affected by
parasites. Detailed studies have to be
carried out on the rates of survival of the caterpillars with a special
reference to the effect of parasites and other factors.
Seasonal variations and flight
period
We made most
of our observations in the Anappady area of Parambikulam TR. We
have images of live field specimens (Image 5) of this butterfly from October to January and we also found new eggs, larvae,
and pupae from November to the end of January.
We saw this species even in May, but we were unable to get photographs. Analysing this, it is assumed that this
species is multivoltine, having several broods in a year presumably strarting from the post monsoon months up to the month of
May. Markings are bold for the
individuals seen in the months of October and November, whereas the markings
are narrower in individuals that are seen in December and January. We presume that the former individuals
represent a wet season form and the later a dry season form. Undoubtedly, we still lack the details on
flight patterns, specific behaviour, and we suggest that future studies pay
more attention to the details on the natural history of this lesser known
species. Also, as Eliot & Kawazoe
(1983) suggested, A. lilacea might have
a wider distribution in India with its range extending up to the northeastern part of India.
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