The Joker butterfly, Byblia ilithyia was multivoltine, and breeds almost throughout the year with high frequency during the periods from September to December. The life cycle from egg to adult emergence was relatively short spanning over 22 - 27 days. Successful development of adults, larvae and pupae are from 80 – 100% during the said period. Short life cycle and high success development of life stages suggest the production of 12 -13 broods in the season. The different stages from egg to adult emergence of Byblia ilithyia on Tragia plukentii was discussed in detail. Nutritional indices consumption index (CI) and approximate digestibility (AD) increase as the larvae aged, while growth rate (GR) increases, efficiency of conversion of digested food (ECD) and efficiency of conversion of ingested food (ECI) are inversely related as age increased.
LIFE CYCLE AND LARVAL PERFORMANCE OF THE JOKER BYBLIA ILITHYIA (LEPIDOPTERA: RHOPALOCERA: NYMPHALIDAE) FROM SOUTHERN ANDHRA PRADESH
1. Bulletin of Pure and Applied Sciences.
Vol.31 A (Zoology),Issue (No.1) 2011:P.1-6
www.bpas.in
LIFE CYCLE AND LARVAL PERFORMANCE OF
THE JOKER BYBLIA ILITHYIA (LEPIDOPTERA:
RHOPALOCERA: NYMPHALIDAE) FROM
SOUTHERN ANDHRA PRADESH
V. Prasanna Kumar, P. Harinath and S.P.Venkata Ramana*
Department of Zoology, Yogi Vemana University, Kadapa-Andhra Pradesh – India
*Corresponding author e- mail: spvramana.butterfly@gmail.com
Received on 5 February 2011: Accepted on 23 May 2011
ABSTRACT
The Joker butterfly, Byblia ilithyia was multivoltine, and breeds
almost throughout the year with high frequency during the periods
from September to December. The life cycle from egg to adult
emergence was relatively short spanning over 22 - 27 days.
Successful development of adults, larvae and pupae are from 80 –
100% during the said period. Short life cycle and high success
development of life stages suggest the production of 12 -13 broods
in the season. The different stages from egg to adult emergence of
Byblia ilithyia on Tragia plukentii was discussed in detail.
Nutritional indices consumption index (CI) and approximate
digestibility (AD) increase as the larvae aged, while growth rate
(GR) increases, efficiency of conversion of digested food (ECD) and
efficiency of conversion of ingested food (ECI) are inversely related
as age increased.
Keywords: Instars, Tragia plukentii, population index, nutritional
indices.
INTRODUCTION
Butterflies are one of the most fascinating creatures symbolically representing
beauty and grace. Byblia ilithyia (Drury) from Nymphalidae was endemic to India
and Sri Lanka with weak flight sails fluttering close to ground (Kehimkar, 2008).
There was an increasing interest all over the world in butterfly conservation. Lack of
complete zoological knowledge of the concerned species including the breeding
habitat was considered to be the reason for such declines and extinctions (New et
al.1995). In India exact status of several species of butterflies are not clearly known
and where there was accelerated distribution of forests and other natural areas
giving to urbanization (Venkata Ramana, 2011). This strategy requires complete
knowledge of life cycle, larval performance in respect of food utilization and growth
and adult nectar resources and other habitat conditions for its successful
implementation. Now we describe here the life cycle and ecobiology of Byblia ilithyia.
2. V. Prasanna Kumar, P. Harinath and S.P.Venkata Ramana*
2
MATERIALS AND METHODS
Field areas were searched for the reproductive activity of Byblia ilithyia during
2011-2012 was found laying eggs on Tragia plukentii. The eggs with the leaf
material were brought to the laboratory and incubated and further development
stages were recorded. Young leaves were supplied daily to growing larval instars.
Details of larval, pupal stages and the adult emergence were recorded from close
observations. Searches were made every month for recording different life stages,
eggs, larvae and pupae on 50 plants of Tragia plukentii to work out the population
index.
RESULTS
These butterflies are weak flyers largely available where food plants were
abundant. Adults were found laying eggs throughout the year with an abundance
during September – December. Tragia plukentii serves as a larval host and it lays
eggs on the young leaves singly.
ADULT
The adults are found on dry and open grassy plains with a wing span of 45-
55 mm, flying weak, close to stems and branches where food plant grows. It is
mostly confined to Indian peninsular. Male and female look alike with slight
variations. Males are bright tawny with narrow black markings in male, dark brown in
female. A row of large white spots present between the two bands with a wing span
of 45 – 55 mm.
Life cycle stages
The egg was yellow in color with prominent ridges from anterior to posterior end.
Anterior end was with pointed tip and posterior end was flattened attached to the
young stems. The egg decolorizes before hatching. The larva feeds on the shell of
the egg after hatching and it takes 3 to 4 days for hatching. The first instar larva was
dark brown in colour with segmented body. The head bears two tri radiated horny
antennae. The entire body on dorsal side and lateral side was covered with tri radiate
horns. This stage remains for 2-3 days and grows to a length of 3.0 mm to 8.0 mm
(7.8±0.07mm). The second instar larva changes from dark brown to green colour.
Dark patches along the dorsal side from anterior region to posterior region are
present. The tri radiate horns on the dorsal side are darker than on the lateral sides.
This stage remains for 2-3 days and grows up to a length of 10.3 mm – 12.8 mm
(12.7 ±0.005). The third instar larva again changes to dark brown in colour. Almost
all the horns too get darker. This stage remains for 2 – 3 days and grows to a length
of 17.2 to 18.3mm (18. ±0.005mm). In the fourth instar white bands develop on the
dorsal side from anterior end to the posterior patches with broken bands except the
last segment. This stage remains for 2-3 days and larva grows to a length of 23.4 to
24.5mm (24.3 ±0.005). The fifth instar larva in this stage remains darker colour
changes to slight purple colour. The horns on the lateral sides were shredded off
before swirls itself. It remains for about 4-5 days before it pupates and larva grows
up to 30.0 – 31.5 mm (31.2 ± 0.02). The final larval stage passes through the pre
pupal stage where it remains for one day and after that it develops the shell around
it and remains for 5 days before the adult emerges out from the pupa. The entire life
cycle from egg to adult emergence completes in 22 - 27 days.
3. LIFE CYCLE AND LARVAL PERFORMANCE OF THE JOKER BYBLIA ILITHYIA (LEPIDOPTERA:
RHOPALOCERA: NYMPHALIDAE) FROM SOUTHERN ANDHRA PRADESH
3
Figure-1: Population index of eggs, larvae, pupae of Byblia ilithyia based on the
searches of 50 Tragia plukentii plants.
Population Index
The numerical frequency of the natural occurrence of the life stages – eggs, larvae
and pupae, on the host plant are given in figure-1. All the stages were spotted out
throughout the year in the study locality. However, there was a higher frequency of
occurrence of the life stages during September to December which corresponds with
the winter season
Fig.2: Relationship between food consumption and growth in Byblia ilithyia
Total food consumption (mg / day)
1.00.75.50.250.00
1.00
.75
.50
.25
0.00
Larvalbodyweight(mg/day)
4. V. Prasanna Kumar, P. Harinath and S.P.Venkata Ramana*
4
Table – 1: Food consumption of Byblia ilithyia larva on Tragia plukentii leaves.
Table – 2: Food utilization efficiencies of Byblia ilithyia larva on Tragia plukentii
leaves
Nutritional indices
Quantitative data of food ingested, the faeces, weight gain by larvae, growth rate &
consumption index were given in Table-1. and Table-2. There is vast increase in the
consumption of food from instar I to V. The weight gain by larva increased from
instar I to instar V. The instar growth rate increased & consumption index decreased
as age increases from instar I to instar V.
Regression of weight gained by larva against the food consumed per day
showed a straight line relationship between these two variable with r value (r=0.93)
and t value (t =2.137) at 0.05 level correlation (Fig.2). The AD values decreased
from Instar I to instar V, the ECD values increased where as ECI values shown a
decline from instar I to V.
DISCUSSION:
Instar
No
Weight of food
ingested (mg)
Wt.of faeces(mg) Wt.gain by larva
(mg)
I 0.0552 0.006 0.011
II 0.064 0.013 0.042
III 0.0832 0.037 0.067
IV 0.092 0.077 0.089
V 0.161 0.119 0.128
Instar
No
GR
(mg/day/mg)
CI
(mg/day/mg)
AD
%
ECD
%
ECI
%
I 2.526 0.092 88 36.75% 64.37
II 2.928 0.048 75 54.25% 64.62
III 3.761 0.030 34 68.24% 51.12
IV 5.022 0.019 22.5 72.75% 47.62
V 5.906 0.026 16 77.5% 46.62
5. LIFE CYCLE AND LARVAL PERFORMANCE OF THE JOKER BYBLIA ILITHYIA (LEPIDOPTERA:
RHOPALOCERA: NYMPHALIDAE) FROM SOUTHERN ANDHRA PRADESH
5
The increasing food consumption at successive instars was in inverse
relationship with consumption index & growth rate. There was gradual increase in
the food consumption from instar to instar. The increased food consumption and
growth rate was considered to accumulate energy rich fat to meet the metabolic
requirements of non feeding pupal and adult stages (Waldbauer 1968; Downer and
Mathew 1976; Slansky and Scriber 1985). The GR values increased & CI decreased
with the age of larvae. The values of GR increased from a low of 2.52 to 5.906 the
later from a high of 0.92 to 0.026. The decline in CI as the larvae aged may be
related to the increase in body size of the larvae or to be the increase in conversion
efficiency of ingested food to body mass. So the high consumption index of early
instars was due to low conversion efficiency (Slansky and Scriber 1985).The AD
values decreased from instar I to instar V. The values of food ECD increase from
early to late instars; an inverse relationship is expected between assimilation
efficiency AD and efficiency of conversion of digested food or net conversion
efficiency ECD (Slansky and Scriber, 1985). The decrease in AD with age was due to
less selective feeding by older larvae, which for leaf chewers like butterfly larvae
results in the consumption of higher proportion of indigestible fiber. Food quality
influences growth efficiencies (Scriber and Feeny, 1979). The resulting ECI may
increase, decrease or show little change depending on the extent to which the
changes in AD and ECD compensate each other.
ACKNOWLEDGEMENT
The senior author Dr. S.P. Venkata Ramana Asst. Professor, Dept. of Animal
sciences, Y.V. University, greatly acknowledge to CSIR, New Delhi for financial
support through a major research project.
REFERENCES
1. Downer , R.G.H. and Mathews, J.R. 1976. Patterns of lipid distribution and utilization
in insects. Amer. Zoolo. 16: 733 – 745.
2. Kehimkar, I. (2008). The book of Indian Butterflies. Bombay natural history society,
Oxford University press, Oxford, New York. pp. 497.
3. New, T.R., R.M. Pyle, J.A. Thomas, C.D. Thomas, and P.C. Hammona. (1995).
Butterfly conservation and management. Annul Review of Entomology, 40: 57-83.
4. Owen, D.F. (1971). Tropical Butterflies. Clarendon Press.
5. Scriber, J.M. and Feeny, P. 1979. Growth of herbivorous caterpillars in relation to
feeding specialization and to the growth form of their food plants. Ecology. 60: 829 –
850.
6. Slansky, F. and Scriber, J.M. 1985. Food consumption and utilization. pp 85- 163. In :
Comprehensive insect Physiology, Biochemistry and pharmacology, Eds. Kerkut, G.A.
and Gilbert, L.I., Pergamon, Oxford.
7. Venkata Ramana, S.P. (2011). The Flying jewels – Butterflies. Sri Venkateswara
publications, Kadapa. A. P. pp.95.
8. Waldbauer, G.P., 1968. The consumption and utilization of food by insects, Advances
in Insect Physiology, 5: 229 – 288.