A new species of caddisfly
(Trichoptera: Lepidostomatidae:Lepidostoma) from Tamil Nadu, India
S. Dinakaran 1, S. Anbalagan 2 & C. Balachandran3
1,2,3 Centre for Research in Aquatic Entomology, The Madura College,
Madurai, Tamil Nadu 625011, India
1 dinkarji@gmail.com
(corresponding author), 2 anbumdu@gmail.com, 3 bchandruji@gmail.com
doi:http://dx.doi.org/10.11609/JoTT.o2116.790 | ZooBank: urn:lsid:zoobank.org:pub:15289A10-EC65-4B6A-85B2-A832D9E4A437
Editor: R. Varatharajan,
Manipur University, Imphal,
India. Date
of publication: 26 January 2013 (online & print)
Manuscript details: Ms # o2116 | Received 05
January 2009| Final received 04 October 2012 | Finally accepted 04 December
2012
Citation: Dinakaran, S., S. Anbalagan & C. Balachandran(2013). A new species of caddisfly(Trichoptera: Lepidostomatidae:Lepidostoma) from Tamil Nadu, India. Journal
of Threatened Taxa 5(1): 3531–3535; doi:10.11609/JoTT.o2116.790
Copyright: © Dinakaran et
al. 2013. Creative Commons Attribution 3.0 Unported License. JoTTallows unrestricted use of this article in any medium, reproduction and
distribution by providing adequate credit to the authors and the source of
publication.
Funding: This study is part of the University Grants
Commission’s funded major project (F.No. 31-216/2005
SR).
Competing Interest: None.
Acknowledgements: We are grateful to Prof. John C. Morse,
Clemson University, Clemson, USA, Dr. Tomiko Ito,
Hokkaido Fish Hatchery, Kita-kashiwagi, Eniwa, Hokkaido-061-1433, Japan and Dr. John Weaver,
Department of Entomology, University of New Hampshire, Durham, USA for help and
support for this study.
Abstract: Lepidostoma nuburagangai, a new species (Trichoptera: Lepidostomatidae),
was collected from Nuburagangai Stream of Alagar Hills, Tamil Nadu, India. The adult male and female, pupa, larva
and case are described. The species
is found in the deposits of dead plant material in slow-moving streams.
Keywords: AlagarHills, caddisfly, Lepidostoma,
new description, southern India.
In the course of our project on gene
banking and habitat inventory of southern Indian caddisflies,
we identified the genus Lepidostoma with
larval morphology and ecology, since they are partially accountable for leaf
litter decomposition. A few species
of this family have been recorded in southern Indian streams such as Lepidostoma fuscatum(Navas, 1932), L. inaequale(Martynov, 1936), L. khasianum(Mosely, 1949) and L. palnicum(Mosely, 1949) and the consolidated details of their
distribution has been provided by the family Lepidostomatidaewhich is distributed throughout the streams of southern India (Dinakaran & Anbalagan 2007,
2010; Anbalagan et al. 2012), but there has been
little attention paid to taxonomic studies of this family in India. During a routine survey, specimens of Lepidostomatidae were collected from the streams of Alagar Hills. Among them, a new species has been observed and the present article
describes this species based on the following features: adult, male, female,
larvae and pupa.
Study
area
AlagarHills: The reserve forests of Alagar Hills (10014’180’’N & 77058’567’’E)
lie 22km northeast of Madurai City. These hill ranges are important pilgrimage sites with seasonal springs (Garudatheertham 350m) and perennial springs like Nuburagangai (425). In the present study, the specimens were collected from Nuburagangai Stream. The maximum and minimum temperatures were 41–29 0C
respectively during summer and 29–22 0C in December. The whole reserve forest area receives
erratic rainfall most of which comes from the retreating northeast monsoon and
a little during the southwest monsoon.
Material and Methods
The
collection, rearing and description procedures were identical to Blahnik & Holzenthal (2004)
and Holzenthal & Andersen (2004). Terminology for genitalia and wing
venation description are according to Ito (2001). The type material is deposited in the
collections of the Centre for Research in Aquatic Entomology (CRE) (Gene bank
accession no. E0070), The Madura College, Madurai, Tamil
Nadu, India.
Lepidostoma nuburagangai sp. nov.
Dinakaran & Anbalagan(Figs. 1–5)
urn:lsid:zoobank.org:act:40EE186E-F432-41DF-A54D-332D5C3C7FB5
Specimens
examined
Holotype: Male, 15.ix.2007, NuburagangaiStream, Tamil Nadu, India (10014’180’’N & 77058’567’’E,
425m), coll. S. Anbalagan & C. Balachandran, deposited in the CRE (E0076). Allotype (adult female): same data as holotype; deposited in the CRE
(E0071). Paratypes:
18 male adults, six female adults, five female pupae, 52 larvae, Nuburagangai stream (10014’180’’N & 77058’567’’E,
425m); 12.xii.2006 (deposited in the CRE E0068), 10 male adults, two female
adults, two female pupae and 47 larvae, same locality, date and collectors as holotype; deposited in the CRE CaddisflyGene bank, Accession number: E0070, 10 male adults, two female adults, 64
larvae (Gene bank, CRE); 25.xii.2006, ThadaganachiammanStream, (8057’.938’’N & 77008’.73’’E,
375m) coll. S. Dinakaran & S. Anbalagan.
Descriptions
Holotype(adult male in alcohol):Yellow, 5.0–5.5 mm long, Antennae 7.0–8.0 mm long. Scape, 0.99mm long, cylindrical, densely covered with numerous
setae and scales (Fig. 1A). Maxillary palpi thick, each 2-segmented,
0.69mm long and densely covered with scales, relative lengths of two segments
from base to apex 1:5. Labial palpi each 3-segmented,
1.1mm long, relative lengths of three segments from base to apex 1:1.5:2; both
pairs of palpi covered with fine setae (Fig.
1A). Forewings,
each 6–7 mm long, 2.5mm wide (Fig. 1B). Hind wings, 4.5–5.0 mm long, 2.3mm
wide (Fig. 1C). Fore- and hind wing
venation as in Fig. 1B closed discoidal and opened thyridial cells present in fore- and hind wings. Genitalia with tergumX consisting of mesal arms and lateral arms and
membranous lobe (Fig. 1D); mesal arms completely
fused medially, apex bluntly triangular with thick setae (Fig. 1E); lateral
arms directed ventrocaudally at basal half, apex
triangular with three setae (Figs. 1D, E). Membranous lobe directed ventrocaudally and
round apically. Phallus,
membranous, slender at basal half, slightly expanded distally (Fig. 1F). Inferior appendages each with main
article thick at base and gradually tapered to apical row of five setae; its harpago tall and hatchet-shaped; its dorsal hook somewhat
triangular and inferior hook bud-like and 1/2 as long as basal width of main
article. Inner
hook short and smaller than basal width of main article. Superior harpage arising on base of main
body of inferior appendage, slender and elongated laterally (Fig. 1D).
Allotype(adult female in alcohol):Yellowish-brown, 5.0–6.0 mm long. Antennae each 7–8 mm long. Scapes each 1.0mm long. Maxillary palpi each 5-segmented and 0.92mm
long, relative lengths of 5-segments from base to apex, 1:1.5:1.5:2:2.5. Labialpalpi each 3-segmented, 0.7mm long, relative lengths
of 3-segments from base to apex 1:1:1.5, both pairs of palpicovered with fine setae (Fig. 2A). Forewings each 6.5–7 mm long (Fig. 2B), hind wings each
5.5–6.0 mm long, fore and hind wing venation as in Figs. 2B,C. Closed discoidaland opened thyridial cells present in fore and hind
wings. Posterolateralmargins of tergum VIII with posterolateralcorners rectilinear; anterolateral corners rectanglularrounded (Fig. 2D). Lateral plate short, pentagonal and strongly sclerotized. Subgenitialplate heavily sclerotized, trapezoidal, with acute posteromedial and lateromedial projections (Fig. 2E). Tergite IX
separated from tergite X by membrane. Vaginal apparatus diamond-shaped with
lateral projections on posterolateral corners,
anterior half of vaginal apparatus tongue-like and weakly sclerotized (Fig.
2F).
Pupa
(female in alcohol):Length 6mm. Antennae
slightly greater than body length and longer than male antennae. Labrum with five pairs of long setae on
dorsum, each seta hooked apically (Fig. 3A). Mandibles heavily sclerotized, each
thick at base and acute at apex, mesal margin
slightly concave, serrate, with numerous very fine sharp teeth on blade (Fig.
3B). Mesotarsi each with dense fringe of
setae (Fig. 3C). Abdominal
segment I with pair of spined ridges (Fig. 3D). Single ventrolateralgills present on segments II and III (posterior), VII and VIII (anterior) and
IV to VI (anterior and posterior). Lateral fringe extending along sides of anterior part of III and along
full lengths of VII and VIII. Pairs
of hook plates on the bases of segments III-VI elliptical with hooks curved
backward, hook numbers and shape varying among individuals and according to
body size (Fig. 3E). Segments
I-VIII each with pair of short dorsal setae (Fig. 3D). Segment VII and VIII each bearing thick
row of lateral brushes of setae. Pair
of triangular anal processes broad basally, depressed and apically angulate,
each with five long setae at apex and many short setae on dorsal and ventral
surfaces.
Final
instar larva (in alcohol):Head width and body length of final instar larva up to 0.53mm and 8–9 mm
respectively. Head, brown with many
round light spots (muscle scars) at posterior half. Primary setae 4, 5, 9 and 10 black;
setae 1, 2, 3, 6, 7, 8 and 11 transparent; setae 2, 9, 10 and 11 very short
(Fig. 4A). Ventral apotome vase-like, 2x as long as posterior ecdysial line separating genae; cardines transversely long, each cardowith mesal apex thickened (Fig. 4B). Mandibles sclerotized, triangular in
dorsal view, each with three teeth at apex and two brushes of setae present on
basal half of mesodorsal blade, posterior brush twice
as long as anterior brush (Fig. 4C). Labrum wide with membranous anterior and lateral margins; setae 1 and 2
blunt and transparent spine-like, situated on membrane; setae 3, 4, 5 and 6
dark brown (Fig. 4D). Antennae each
situated just anterior of periocular spot, short,
twice as long as basal width and not segmented. Pronotumsclerotized dorsally, concolorous with head, bearing
8 pairs of setae on anterior margin; mid-dorsal ecdysialline clear; anterolateral corners rectangular, posterolateralcorners triangular (Fig. 5A). Mesonotum separated into two dorsolateral plates by very
narrow dorsomedian membranous ecdysialline, anterolateral corners and posterolateralcorners rounded. One seta on each sa 1,5 setae on each sa 2 and 7–8 setae on each sa3. Metanotalarea broadly membranous, slightly sclerotized at the bases of setae in setal areas, 1 seta on each sa 1
and sa 2 and 5–6 setae on each sa 3. Thoracic
legs, light brown, with small dark spot near posterior apicodorsalcorner of each femur. Foreleg,
shortest (Fig. 4E) and middle leg longest (Fig. 4F). Trochantero-femoral brushes of fore, and hind legs consisting of numerous
comb-like setae (Fig. 4G). Numerous spinules covering mesal surfaces of forecoxae and anterobasal areas of hind coxae. Abdominal segments with lateral tubercules present on sides of segment I, each with two
long setae and numerous pectinate spines. Lateral fringe and forked lamellae in
longitudinal row on each side of segments III-VII (Fig. 5D). Single tracheal gills present subventrally and subdorsally on
segments II-VII; segment VIII with broad lobe at each side. Segment IX,short, wide dorsal sclerite with two pairs of long setae and two pairs of
short setae on apical margin (Fig. 5B). Anal legs each with anal claw, each anal claw bearing one accessory hook
(Fig. 5C).
Larval cases: Length of 4-sided case up
to 7–8 mm. Cylindrical, sand
case built by earlier instars and 4-sided leaf-piece case built at 5thinstar; posterior end with round opening (Figs. 5E-I).
Etymology
The new species is named after the
stream, Nuburagangai located at Alagar Hills, Tamil Nadu, southernIndia.
Habitat
and Biology
Gut contents of larvae (n = 25) showed
the presence of fragments of partially decomposed leaf litter and woody
debris. Larvae were found in
slow-moving streams where leaf litter and woody debris were deposited. Abundant larvae were found in leaf
litter in riffle areas than in leaf litter in pools. Larvae were abundant during early summer
(March & April) and spring (June to August). Physico-chemical
characteristics of the collection sites were: stream width 1.9±0.51 m, depth
5±2 cm, stream flow 8±2 mS-1, temperature 26±2.08 0C, pH
6.9±0.06, dissolved oxygen 16.2±1.1 mgL-1.
Diagnosis
Lepidostoma nuburagangai sp. nov. closely resembles L.palnia (Mosely, 1949)
but can be distinguished by the following combination of characters: In the
adult male of Lepidostoma nuburagangai sp. nov.,
maxillary and labial papli characters, wing venation,
each inferior appendage has a hatchet-shaped harpagoat its apex, inner hook short and smaller than basal width of main article, and
the lateral arms of tergum X each has its apex more
rounded than those of the adult male of L. palnia.
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