CURRENT SCIENCE, VOL. 110, NO. 4, 25 FEBRUARY 2016 504
the body of hydra7. Long-term exposure
to waterborne iron led to a significant
accumulation of metal in liver that
caused tissue damage in fish6. Although
iron depositions were not detected in
mesoglea, morphometric measurement of
mesoglea verified various thickness
values (Figure 2), presumably due to its
largely non-cellular structure. It is assu-
med that mesoglea represents a buffer of
some sort13. Exposure to iron can cause
the retention of water in mesoglea, due to
its inability to eliminate excess water
from the body by contracting14 and can
enhance synthesis of its constituents,
which can thicken mesoglea.
In conclusion, non-symbiotic brown
hydra exhibited greater susceptibility to
iron. Symbiotic green hydra survived
better in the given micro-environmental
conditions. The present study may point
towards the advantages of symbiosis in
the living world.
1. Martin, H. M. and Coughtrey, P. J., Bio-
logical Monitoring o f Heavy Meta l
Pollu tion . Lan d and Air , Applied Science
Publishers, London and New York,
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Kopjar, N., J. Fish Biol., 2008, 72,
7. Kovačević, G., Želježić, D., Horvatin, K.
and Kalafatić, M., Symbios is, 2007, 44,
8. Kasahara, S. and Bosch, T. C. G., Dev.
Comp . Immunol ., 2003, 27 , 79–166.
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Habdija, B., Biologia Bratislava, 2005,
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11. Furmańska, M., Pol. Arch. Hydrobiol.,
1979, 26 , 213–220.
12. Martin, T. R. and Holdich, D. M., Water
Res., 1986, 20, 1137–1147.
13. Kovačević, G., Kalafatić, M. and
Horvatin, K., Folia Bio l. Krakow, 2009,
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parative Biochemist ry and Physiology,
Part A. Ph ysio logy , 1972, 43, 165–171.
ACKNOWLEDGEMENTS. We thank Ms
Nadica Vincek for technical assistance. We
acknowledge the support of the Ministry of
Science, Education and Sport of the Republic
of Croatia (project 119-1193080-1214 ‘Mo-
lecular phylogeny, evolution and symbiosis of
Received 6 October 2015; revised accepted 6
GORAN KOV AČEV IĆ1,*, †
ANA MATI JEVIĆ3
1Faculty of Science,
University of Zagr eb,
Department of Biology,
Zoology, Rooseveltov trg 6,
HR-10000 Zagreb, Croatia
2Ministry of Health,
Department of Phar maceutical
HR-10000 Zagreb, Croatia
3Universit y Hospital Centre Zagreb,
Department of Laboratory Diagnostics,
Kišpatićeva 12, HR-10000 Zagreb,
†Equally contributed to this paper.
Aquilaria malaccensis fruit borer in Peninsular Malaysia
Aquilaria malaccensis Lam. (Thyme-
laeaceae) has a natural distribution in
lowland tropical forests in Peninsular
Malaysia, India, Myanmar, Sumatra,
Singapore, Borneo and the Philippines.
The tree is highly valued for its resin,
known as agarwood or popularly known
as ‘gaharu’ in the region, which is uti-
lized in various products such as perfum-
ery, incense, decorative carvings and
pharmaceutical products. Agarwood is
produced when an agarwood-producing
tree is wounded or infected with fungi,
microorganisms or insect borers, whereby
the borers could also act as a vector of
diseases1. Only 10% of trees in the wild
can become infected by the fungi2 and
produce the much-sought-after resin.
Indiscriminate felling of agarwood-
producing trees, especially A. malaccen-
sis, in the forests has gone beyond con-
trol in certain countries. The harvested
quantity of agarwood is, however, very
low, with less than 0.2 kg per tree for a
A. malaccensis is currently listed as
vulnerable according to the IUCN Red
List4 due to overexploitation. Conserva-
tion of A. malaccensis is important to en-
sure the sustainability of resources, and
this requires an understanding of its re-
productive biology5, which is lacking.
Therefore, a series of phenological stud-
ies were conducted on wild A. malaccen-
sis trees in the forested areas at Penang
Island and Perak, Malaysia beginning
2011. The fruits and seeds were also col-
lected from each study site by placing
10–20 square-framed nettings measuring
1 m 1 m each under the tree prior to the
fruiting season for abortion and germina-
tion studies. Damaged fruits were scruti-
nized for the presence of insect pests.
In Penang, one of the aborted and
damaged fruits from a total of 1144 had a
mature larva living inside and was seen
feeding on the fleshy capsule (Figure 1),
whereas in Perak a larva was found in-
side an aborted fruit randomly picked
from the ground. A hole measuring about
3 mm in diameter was seen penetrating
through the capsule into the fleshy part
(Figure 2). The larvae were extracted and
Figure 1. Larva partially concealed within
its feeding tunnel (arrow).
CURRENT SCIENCE, VOL. 110, NO. 4, 25 FEBRUARY 2016 505
reared in a plastic container lined with
tissue paper at 26–28C and 60–80%
humidity in the laboratory. The larva was
yellow in colour with black knobs lining
Figure 2. Bore hole on the surface of Aqui-
laria malaccensis fruit.
Figure 3 a–c. Life stages of Pitam a herme-
salis. a, Mature larva. b, Pupa. c, Adult.
the dorsal and lateral surface of its ab-
domen (Figure 3 a). It also had fine setae
protruding from the sides of its abdomen.
The larvae pupated 3–6 days later under-
neath the fold of the tissue paper. The
adult moth emerged after 14 days in
pupation (Figure 3 b). The pupa from the
larva sample collected in Penang, how-
ever, failed to emerge. The moth was
identified as Pitama hermesalis Walker
(Lepidoptera: Crambidae) according to
Robinson et al.6 with a wingspan of
30 mm (Figure 3 c). To our knowledge,
there are no previous records of the moth
species found infesting the fruits of wild
A. malaccensis tree.
The fruits of A. malaccensis could be
an alternative host to P. hermesalis as its
larva is usually observed feeding on the
leaves of wild and planted A. malaccen-
sis in Peninsular Malaysia. The larva has
a preference to live and feed between the
folds of two leaves that were attached
together using silk web. The green area
on the leaves was scraped-off causing it
to become translucent (S. P. Ong, pers.
obs.). Elsewhere in Indonesia, P. herme-
salis has also been reported feeding on
the leaves of Aquilaria sp. trees7.
Although the larva may not be feeding
on the seed, the damage was enough to
cause the fruit to abort prematurely (Fig-
ure 4), thus leading to underdeveloped
seed. More studies are needed to assess
the damage rate caused by P. hermesalis,
Figure 4. Feeding damage and frass of
Pitam a hermesa lis inside the aborted fruit.
although early observations show that
fruit feeders such as macaques and squir-
rels have a greater impact.
1. Donovan, D. and Puri, R., Ecol. Soc.,
2004, 9, 3.
2. Gibson, I. A. S., B ano Biggyan Patrika,
1977, 6(1), 16–26; Ng, L. T., Chang, Y. S.
and Kadir, A. A., J. Trop. For. Prod.,
1997, 2, 272–285.
3. Soehartono, T. and Newton, A. C., Biol.
Conserv., 2001, 97 , 29–41.
4. Asian Regional Workshop (Conservatio n
and Sustainable Management of Trees,
Viet Nam, August 1996), 1998. Aquilaria
mala ccens is. T he IUCN Red List of
Threatened Species. Version 2014.3;
www.iu cnredlist.org (retrieved on 20
5. Lau, K. H. and Chua, L. S. L., In Asia and
the Pacific Workshop – Multinational and
Transboundary Conservation of Valuable
and Endangered Forest Tree Species (eds
Sim, H. C., Syuqiyah, A. H. and Li, M.),
IUFRO World Series 30, 2012, pp. 43–45.
6. Robinson, G., Tuck, K. and Schaffer, M., A
Field Gu ide to the Smaller Moths of
Southeast Asia , Malaysian Nature Society,
Kuala Lumpur, 1994.
7. Lestari, F. and Suryanto, E., Serangan
Hama Ulat Pitama hermesalis Pada
Tanaman Penghasil Gaharu di Kandangan
Kalimantan Selatan, Seminar Hasil Hutan
Bukan Kayu, Balai Penelitian Kehutanan
ACKNOWLEDGEMENTS. We thank ITTO
Work Program element ‘Support to ITTO–
CITES Implementation for Tree Species and
Trade/Mark et Transparency’ for financial
assistance, and all those who helped during the
field excursion in Penang Island and Perak.
Received 16 March 2015; accepted 6 October
S. P. ONG*
K. H. LAU
Forest Research Institute Malaysia,
52109 Kepong, Selangor, Malaysia