Journal of Threatened
Taxa | www.threatenedtaxa.org | 26 March 2024 | 16(3): 24992–24995
ISSN 0974-7907
(Online) | ISSN 0974-7893 (Print)
https://doi.org/10.11609/jott.8341.16.3.24992-24995
#8341 | Received 24 December 2022 | Final received 19 July 2023 | Finally
accepted 18 December 2023
First report of moth species of
the family Tineidae (Lepidoptera) in regurgitated
pellets of harriers in India
S. Thalavaipandi
1, Arjun Kannan 2, M.B. Prashanth 3 & T. Ganesh
4
1-4 Suri Sehgal Centre for
Biodiversity and Conservation, Ashoka Trust for Research in Ecology and the
Environment (ATREE), Jakkur P.O., Bengaluru,
Karnataka 560064, India.
2 Manipal Academy of Higher
Education (MAHE), Manipal, Karnataka 576104, India.
1 thalavaipandi@atree.org
(corresponding author), 2 arjun.kannan@atree.org, 3 prashanth.mb@atree.org,
4 tganesh@atree.org
Editor: Anonymity requested. Date of
publication: 26 March 2024 (online & print)
Citation: Thalavaipandi, S., A. Kannan, M.B. Prashanth & T.
Ganesh (2024). First report of moth species of the family Tineidae
(Lepidoptera) in regurgitated pellets of harriers in India. Journal of Threatened Taxa 16(3): 24992–24995. https://doi.org/10.11609/jott.8341.16.3.24992-24995
Copyright: © Thalavaipandi et al. 2024. 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: Core research grant DST-SERB
(SB/SO/AS/0932013 and EMR/2017/002235). TVS brakes India, Sundaram finance.
Competing interests: The authors declare no competing interests.
Acknowledgements: We thank A. Saravanan, S. Tamizhazhagan, and Aditya Ganesh for their assistance in
collecting harrier pellets. We would like to thank Jahir Rayhan
for the confirmation of the moth family. This research is funded by a core
research grant from DST-SERB to TG as part of the long-term harrier monitoring
work.
Abstract: Caterpillars of Tineidae
moths mainly feed on keratin sources and require moisture and warm temperature
for emergence. The presence of Tineidae moth
caterpillars, pupae, and adults in regurgitated pellets of harriers, diurnal
migratory raptors wintering in India, suggests a potential dietary association
and highlights the importance of considering associated organisms in raptor diet
estimation studies. The caterpillars preferred rodent hairs present in the
pellets over feather and arthropod remains. This is the first record of Tineidae moths on the pellets of harriers.
Keywords: Arthropods, caterpillar, diet, grassland, Harrier, Maharastra, Monopis,
pellets, pupae, raptor, regurgitate, Tineidae, Tirunelveli, undigested.
Regurgitating pellets to eject
indigestible matter from the gizzard is observed in about 330 species of birds
belonging to more than 60 families (Glue 1973). Among these families, pellets
ejected by raptors usually contain undigested prey materials such as fur,
feathers, bones, scales, and chitin (Philips & Dindal
1979). Pellets generally decompose within a few weeks to months (Wilson 1938;
Marti 1974), but it
can also remain intact for several years (Brooks 1929; Prestt
& Wagstaffe 1973). Most times, pellets either
disintegrate on their own due to local weather conditions or are eaten by a
variety of arthropods, including ants and beetles. Caterpillars are rarely
found in pellets since they mainly feed on plant parts such as leaves, floral
tissue, or fruits (Young 1997).
However, a particular group of
moth caterpillars belonging to the family Tineidae
feed on resources other than plant parts such as fur, feathers, arthropod
remains, guano, wool, and hair (Robinson & Nielsen 1993) that are rich in
keratin and chitin. Tineidae caterpillars are
commonly found in bird nests, and undigested prey contents in raptor pellets
form a significant part of their diet (Robinson & Nielsen 1993; Robinson 1998;
Terry 2004; Sato et al. 2019). They aid in pellet decomposition by feeding on
the fur and feather remains in pellets (Philips & Dindal
1979). Tineidae caterpillars also construct a
tube-like larval case made out of the fur and feather remains in pellets (Nasu et al. 2007). Raptor pellets are known to support many
invertebrates such as ants, trogid beetles and Tineidae
moths for their breeding, feeding, and shelter requirements (Philips & Dindal 1979). Previous studies have recorded several moth
species of the Tineidae family, i.e., Monopis congestella,
M. pavlovskii, M. crocicapitella, and M. longella in the nests and pellets of the Great
Horned Owl (Philips & Dindal 1979), Ural Owl and
Goshawk (Nasu et al. 2008), eagles (Sharkov et al. 2003), and in bat droppings (Byun et al.
2014; Heckford & Beavan 2018). In New York, a
single pellet of the Great Horned Owl had 60 caterpillars of Tineidae moths in it (Philips & Dindal
1979). However, Tineidae moths have not been recorded
from harrier pellets previously.
Here, the occurrence of Tineidae moth caterpillars in harrier pellets and their
potential role in influencing raptor diet estimation studies is described.
Materials and Methods
The study focused on
investigating the diet of harriers in their Indian wintering range,
specifically in Rengarajapuram, Tamil Nadu state
(8.5474, 77.7039) and Dahiwadi, Maharashtra (17.8243,
76.0504), from 2016 to 2022. Harrier pellets, regurgitated remnants of prey,
were collected from roosting sites predominantly utilized by Montagu’s Harrier Circus
pygargus, Pallid Harrier Circus macrourus, and Western Marsh Harrier Circus aeruginosus. To prevent fungal attacks and ensure the
preservation, the collected pellets were sun-dried and subsequently packed in
zip-lock covers. Morphological measurements including length and breadth were
taken for each pellet in the laboratory. Prior to dissection, the pellets were
soaked in water, facilitating the identification of prey items. Observations
were made within the zip-lock packets to monitor caterpillar emergence,
followed by a week-long observation period to determine the number of pupae
present in the disintegrated pellets, thus providing an estimate of the emerged
larvae or adults. These methods enabled a comprehensive analysis of the
harriers’ diet in the specified region and time frame.
Results and
Discussion
The study provides the first
record of Tineidae moth caterpillar, pupae, and
adults occurring in harrier pellets. A total of 160 pupae were found in the
pellets with a maximum of 38 pupae from one single pellet collected from
Maharashtra in 2017; 15 pellets were collected from this harrier roost site and
stored in a zip-lock cover. While examining these pellets to ascertain the diet
of harriers, we initially observed a few dead caterpillars in the zip-lock
packets. The caterpillars were white colored with brownish heads (Image 2). The
adult moths were also present on the pellets with creamy white heads, and erect
scales on vertex and frons. They had a filiform antenna; scape with black and
brownish scales; basal of the wing black; forewings with black and white color
in equal proportions and the apex was dull black and the termen
white. There was a trace of a darker subterminal line originating from the apex
and retracting in the middle before which there were two tiny black dots. Based
on the above morphological characteristics, the moths were identified to be
belonging to the genus Monopis (Kristensen
1999).
In 2021, during the collection of
pellets from a roosting site in Tamil Nadu, a caterpillar belonging to the
genus Monopis sp. was once again recorded.
Despite the complete disintegration of the pellets, a total of 132 pupae were
identified. Notably, within the same set of pellets, another Monopis species, specifically Monopis
cf. monachella (Huang et al. 2011), was
documented. This species exhibited distinctive characteristics, including a
vertex and frons covered with erect white piliform scales (Image 3), filiform
antennae, elongated wings with a moderately rounded apex, and a simple forewing
pattern consisting of a round, purple-black color with a large rectangular
oblique white marking on the costa, encompassing the subhyaline spot at the end
of the discoidal cell (Robinson et al. 1994). Significantly, the collection of
these pellets occurred shortly after a period of significant rainfall in the
region. Despite the inability to determine the exact number of pellets, these
findings provide valuable insights into the presence of Monopis
species and their association with the harrier diet in the Tamil Nadu
roosting site.
Based on the analysis of pellet
remains, it was evident that caterpillars exhibited a clear preference for
consuming pellets that contained rodent hairs, followed by bird feathers
(Figure 1). However, it is noteworthy that the caterpillars did not consume the
available grass, seeds, bones, bird gizzard, or eggshells found within the
pellets. The outer surface of the pellets remained intact, and the presence of
caterpillar frass was observed inside the pellets,
indicating that the caterpillars had actively fed on the pellet contents.
The life cycle stages of tineid moths, including their eggs, larvae, and pupae, are
known to be sensitive to environmental variables, such as temperature and
humidity (Griswold & Crowell 1936). Temperature fluctuations have been
shown to significantly influence the egg-laying behavior of these moths (Brimblecombe & Lankester
2013). Although the pellets were thoroughly dried and carefully packed, the
emergence of caterpillars and a few adults from the zip-lock packets indicated
that the moths may have laid their eggs while the pellets were still in the
field before collection. Subsequently, these eggs remained dormant until they
were exposed to moisture upon opening the bags in the laboratory. An
alternative explanation could be that the larvae were already feeding on the
pellet contents from within, and the water soaking process stimulated to come
out from the pellet. It is important to note that certain moth species can
maintain prolonged dormancy as eggs, caterpillars, or pupae (Young 1997). To
further validate these assumptions, additional in-depth investigations on the
ecology and behavior of Tineidae moths are warranted.
This observation marks the
first-ever documented instance of Tineidae moth
caterpillars within harrier pellets. The identification of Tineidae
moths as the decomposers of these pellets highlights the need to explore the
factors that facilitate their egg-laying and pupation processes, as not all
collected pellets across the years showed signs of infestation. Understanding
these conditions is crucial, as they can potentially affect the availability of
pellets and introduce biases in dietary estimates, not only for harriers but
also for other raptors. If Tineidae moths frequently
disintegrate harrier pellets containing feathers and hairs, it can lead to a
skewed representation of the dietary preferences of these birds, favoring
alternative prey categories in the estimations. Therefore, further
investigations into the interaction between Tineidae
moths and harrier pellets are essential for accurate dietary assessments and to
avoid potential biases in ecological studies involving raptors.
The distribution of tineid moth species in India is currently poorly
documented. The presence of M. monachella
in the pellets collected from Tamil Nadu is noteworthy, as previous records of
this species were limited to Kerala and Karnataka, where it was identified
using light traps (Pathania & Rose 2004).
Therefore, our study provides the first distribution record of M. monachella in Tamil Nadu. On the other hand, the tineid moth in the pellets collected from Maharashtra could
not be identified at the species level due to the unavailability of type
specimens. This highlights the pressing need for comprehensive taxonomic
studies on moths, particularly within grassland ecosystems, which have received
limited attention thus far. Such preliminary information is crucial for studying
host-specificity and can provide valuable insights into the conservation status
of these moths, especially considering the declining status of harrier
populations due to landscape changes and the loss of grasslands (Ganesh &
Prashanth 2018; Saravanan et al. 2021).
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References
Brimblecombe, P. & P. Lankester
(2013). Long-term
changes in climate and insect damage in historic houses. Studies in
Conservation 58(1): 13–22. https://doi.org/10.1179/2047058412Y.0000000051
Brooks, A.
(1929). On Pellets of
Hawks and Owls. Condor 31: 222–223.
Byun, B. K.,
Shin, S. B., Bae, Y. S., Kim, D. S., & Choi, Y. G. (2014). First discovery of a
cave-dwelling Tineid moth (Lepidoptera, Tineidae) from East Asia. Journal of Forestry Research 25:
647–651.
Ganesh, T.
& M.B. Prashanth (2018). A First Compilation of Harrier Roost Counts from India Suggests
Population Declines of Wintering Birds over 30 Years. Ardea
106(1): 19–29. https://doi.org/10.5253/arde.v106i1.a6
Glue, D.E.
(1973). Owl pellets
pp. 193–197. In: Dutton, E.P. (ed.). Owls of the World: Their Evolution,
Structure, and Ecology. New York, 216 pp.
Griswold,
G.H. & M.F. Crowell (1936). The effect of humidity on the development of the
Webbing Clothes Moth (Tineola bisselliella Hum.). Ecology 17(2): 241–250. https://doi.org/10.2307/1931463
Heckford, R.J. & S.D. Beavan (2018). Monopis crocicapitella: case bearing larvae in England
found feeding on bat droppings. Entomologist’s Record 130: 233–248.
Kristensen,
N.P. (1999). Lepidoptera,
Moths and Butterflies. 1: Evolution, Systematics, and Biogeography. de Gruyter, Berlin, 491 pp.
Marti, C.D.
(1974). Feeding
ecology of four sympatric owls. Condor 76: 45–61.
Nasu, Y., G.-H. Huang, S. Murahama & T. Hirowatari
(2008). Tineid moths
(Lepidoptera, Tineidae) from Goshawk and Ural Owl
nests in Japan, with notes on larviparity of Monopis congestella
(Walker). Lepidoptera Science 59(3): 187–193.
Nasu, Y., S. Murahama,
H. Matsumuro, D. Hashiguchi & C. Murahama (2007). First record of Lepidoptera from
Ural Owl nests in Japan. Applied Entomology and Zoology 42(4): 607–612. https://doi.org/10.1303/aez.2007.607
Pathania, P.C. & H.S. Rose (2004). First record of the genus Compsoctena Zeller (Lepidoptera: Eriocottidae)
from India. Zoos’ Print Journal 19(6): 1501–1504. https://doi.org/10.11609/JoTT.
ZPJ.1056.1501-4
Philips, J.R.
& D.L. Dindal (1979). Decomposition of raptor pellets. Raptor
Research 13(4): 102–111.
Prestt, I. & R. Wagstaffe
(1973). Barn and bay
owls pp. 42–60. In: Dutton, E.P. (ed.). Owls of the World: Their Evolution,
Structure, and Ecology. New York, 216 pp.
Robinson,
G.S. (1998). Lepidoptera,
Moths and Butterflies pp. 92–100. In: Kristensen, N.P. & A. Schmidt-Rhaesa (eds.). Evolution, Systematics, and Biogeography.
Walter de Gruyter, Berlin, 501 pp.
Robinson,
G.S. & E.S. Nielsen (1993). Tineid Genera of Australia
(Lepidoptera) (Monographs on Australian Lepidoptera Series) Vol. 2. CSIRO publications, Melborune, Australia, 344 pp.
Robinson,
G.S., K.R. Tuck & M. Shaffer (1994). A Field Guide to the Smaller
Moths of South-East Asia. Malaysian Nature Society, Malaysia, 1308 pp + 32
pls.
Saravanan,
A., M.B. Prashanth & T. Ganesh (2021). Wintering harriers in a rapidly
changing landscape in southern Tamil Nadu, India. Current Science
120(3): 9.
Sato, H., Y. Nasu, S. Murahama, H. Matsumuro & K. Ueda (2019). Differences in the niches of
keratin/chitin feeding moths (Lepidoptera: Tineidae)
in bird nests in central Japan. European Journal of Entomology 116:
442–449. https://doi.org/10.14411/eje.2019.045
Sharkov, A., T.E. Katzner
& T. Bragina (2003). A new Species of Copidosoma Ratzeburg
(Hymenoptera: Encyrtidae) from Eagle Nests in Kazakhstan.Journal of Hymenoptera Research 12(2):
308–311.
Terry, R.C.
(2004). Owl pellet
taphonomy: a preliminary study of the post-regurgitation taphonomic
history of pellets in a temperate forest. Palaios
19(5): 497–506. https://doi.org/10.1669/0883-1351(2004)019<0497:OPTAPS>2.0.CO;2
Wilson, K.A.
(1938). Owl studies. Michigan
55: 187–197.
Young, M. (1997). The Natural History of Moths. T & AD Poyser
Ltd, 271 pp.