Some new Chironomidae from south and middle Andaman Islands, India (Diptera: Chironomidae)

16 Pages·2001·7.3 MB·

by  Girish Maheshwari

SOME NEW CHIRONOMIDAE FROM SOUTH AND
MIDDLE ANDAMANISLANDS, INDIA (DIPTERA: CHIRONOMIDAE
1
)
GirishMaheshwari2andGeetaMaheshwari3
(Withfour text-figures)
Key words: Diptera, Chironomidae, Andaman Islands, India
Little information is available on the Chironomidae ofthe Andaman and Nicobar Islands. Two
newgenera,namelyIndoaxarusgen.no\.,Andamanusgen.nov.andonenewspeciesLindebergia
kadamtullaensis sp. nov. are being described.
Introduction ventral and median lobes. Cercus setose and
triangular.
Lindebergia Tuiskunen is a monotypic
genus, based on a single male specimen, Andamanusmaniigen. nov. sp. nov.
L. bothnica Tuiskunen. The taxonomic status (Figs la-e)
of the genus was doubtful. Its independent
taxonomicstatusisbeingestablishedbycladistic Description: Female Imago: Total body
analysis in this paper. A new species length 2.51 mm; wing length 1.88 mm.
L. kadamtullaensissp.nov. isalsodescribed.Two Antenna: Scapepoorlydeveloped;pedicel
new genera and species namely Andamanus rounded with two setal patches, anterior setal
maniigen.nov.,sp.nov.andIndoaxarussantokhi patchwith6-7setaeandposteriorwith5-7 setae.
gen. nov., sp. nov. are alsobeingdescribedfrom Length/width of lst-4th flagellomeres: 0.136/
Andaman and Nicobar Islands. 0.033; 0.077/0.025; 0.077/0.022; 0.154/0.022
The structure and terminology ofSaether mm. First flagellomere larger than 2nd and 3rd
,
(1980) hasbeen followed. withtwobeadedstructures, twowhorls ofsetae,
one on each. Second and third flagellomeres
Subfamily: Orthocladiinae conical, each with a single whorl of 5-8 setae.
GenusAndamanus gen. nov. Ultimate flagellomerebeaded, broadbasedwith
a whorl of three setae on distal end. Antennal
Diagnosis: Habitat: Intertidal zone along Ratio (AR) 0.531.
the shoreline. Medium sized, pedicel rounded Head: Coronal suture incomplete, 0.109
mm
with two setal patches, antennal ratio 0.531, long; temporal setae 20, frontal tubercle
coronal suture incomplete, antepronotal lobes absent,eyesbare,bean-shaped,withweakdorsal
with dorsal notch, acrostichals absent, costa not extension. Length and width of clypeus 0.060
extending beyond the tip ofR Claws curved, and0.065mm,clypeusbears28setae.Maxillary
45.
pulvilli absent, spermatheca single with neck, palpswithfivepalpomeres, length/width: 0.026/
ramusweakandshort,intergonocoxalmembrane 0.021; 0.039/0.034; 0.104/0.030; 0.113/0.026;
present, gonapophysisVIIIisdividedintodorsal 0.217/ 0.017 mm. Tentorium tube, sieve tube,
sieveporepresent,cornuablunt,orificerounded;
'AcceptedMay,1999 labial lonchus elongatedwithroundedproximal
:SchoolofEntomology,St.John’sCollege,
end. (Fig. la)
Agra282002,UttarPradesh,India.
'DepartmentofZoology,B.S.A.College, Thorax: Antepronotal lobe reaching the
Mathura281 004,UttarPradesh,India. projection of scutum, joining medially with a
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NEWDESCRIPTIONS
narrow notch, bare. Dorsocentralis 18-20 in a
single row. Acrostichals absent, scutellum with
11-13 scutellars.
Wings: Subcosta short, ending before Rj,
R, ending distal to r-m R very weak. Costa
, 2+3
not extending beyond the tip of R Squama
4+5.
not fringed (Fig. lc).
Legs: Fore tibial apex with a blunt scale,
spur absent, claws curved. Mid tibial apex with
two combs, dorsal complete with a single spur,
ventral with a peg-like spur. Length of spurs
0.040 and 0.018 mm. Hind tibial apex with a
mm
single comb including 0.063 long spur.
Pulvilli and empodium absent.
Female Genitalia: Spermatheca single,
elongated, with neck, spermathecal duct opens
independentlyintospermathecaleminence.Notum Fig. lb: Andamanusmanii: Anteropronotum lobe
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NEWDESCRIPTIONS
mm
0.2
Fig. lc: Andamanusmanii: Wing
FORELEG MIDLEG HINDLEG
mm
0.02
Fig. Id: Andamanusmanii: 9legs (First row: tibial apex, second row: fifth tarsal)
408 JOURNAL, BOMBAYNATURAL HISTORYSOCIETY, 98(3), DEC 2001
NEWDESCRIPTIONS
Table1
MEASUREMENTSOFLEGS(INMM)ANDLEGRATIO(LR)OFANDAMANUSMANII
Fe Ti Ta, Ta Ta Ta Ta LR
: ? 4 5
p, 0.872 0.631 1.095 0.5568 0.445 0.363 0.159 1.735
p„ 1.063 0.963 0.681 0.3891 0.340 0.200 0.113 0.707
p; 0.927 0.877 0.436 0.263 0.204 0.136 0.090 0.497
elongated,ramusweakandshort. Labiaelongated Type locality: Mayabunder, Middle
withmicrotrichia.Postgenitalplatebroad,rounded. Andaman; Andaman and Nicobar Is.; India.
Intergonocoxal connective membrane present. Etymology:NamedafterProf.M.S.Mam,
Gonapophysis VIII setose divided into dorsal, the founderofSchoolofEntomology.
ventral and median lobes. Gonocoxal apodeme Holotype: 1 9 Mayabunder, Middle
extending to proximal end ofcoxostemapodeme. Andaman, 21.xii.1983, Coll. G. Maheshwari.
Cercus setose andtriangular (Fig. le). Deposited in the collection of School of
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NEWDESCRIPTIONS
Entomology, St. John’s College, Agra; India, Lindebergia kadamtullaensis sp. nov.
(Regn. No. Ch. 21). (Figs 2a-f)
Paratype:Regn.No.Ch.21a,one 9 same
,
data as holotype. Description: Male Imago: Body length
Systematics: The new genus Andamanus 2.39 mm, wing length 1.397 mm, wing width
resemblesthegenusHalocladiusHirvenojafrom 0.397mm,bodylength : winglengthis 1.71:1.0.
the coastal brackish waters of the Holarctic Antenna: Scape well developed andbare,
Region. It also has certain affinities with pedicel coveredwithmicrosetae, flagellumwith
Cricotopusv.d.WulpandParacladiusHirvenoja. 13 flagellomeres, a median groove extends
Halocladius CricotopusandParacladiuscanbe between 3rd and ultimate flagellomeres,
,
distinguishedfromAndamanus gen. nov. bythe distribution of setae from 1st to ultimate
presence of a decumbent dorsocentralis. flagellomeres is 2-4, 9-11, 10-11, 10-12, 11-13,
Paracladius can be separated by prealars not 8-10, 10-12, 11-13,7-10, 10-11,9-11, 10-12and
extending anterior to level of median 75-85 respectively. Lengthand width ofpedicel
anepistemumIIandbaremediolongitudinalarea 0.88 and 0.114 mm. Length and width of
oftergite. Cricotopus and Halocladius can also flagellomeres 1st-13th (in mm): 0.047, 0.025;
be distinguished fromAndamanus gen. nov., by 0.018, 0.025; 0.025, 0.025; 0.025, 0.022; 0.025,
hairy eyes. Female ofAndamanus gen. nov. can 0.023; 0.029, 0.020; 0.031, 0.018; 0.033, 0.018;
be identified by a combination of characters: 0.035, 0.018; 0.036, 0.016;-0.036, 0.014; 0.036,
scape poorly developed, coronal suture 0.016; 0.321, 0.016. Antennalratio (AR) 0.853.
mm
incomplete, frontal tubercles absent, eyes bare, Head:Coronalsuturecomplete,0.166
sieveporespresent, antepronotal fuseddorsally, long, frontal tubercle present, temporal setae 5
subcostashortandendingbeforeR, pulvilliand (2 frontals, 3 post orbitals). Eyes bare without
,
empodiumabsent,spermathecasingle,elongated dorsal extension. Length and width of clypeus
mm
with spermathecal neck. 0.051 and 0.099 respectively, with 18-22
Remarks: Adults were found gyrating on setae. Maxillary palp with five palpomeres,
the water surface in the intertidal zone. length and width ofpalpomeres: 0.018, 0.014;
0.033, 0.020; 0.073, 0.018; 0.121, 0.16; 0.11,
mm
Subfamily: Orthocladiinae 0.016 respectively. Tentorium arm tubular,
Genus Lindebergia Tuiskunen anterior tentorium pit and sieve pores absent;
stipes narrow, cornua blunt and curved, orifice
Lindebergia Tuiskunen, Ann. ent. Fenn. not seen, labial lonchus elongated and porous
50:121 (Fig. 2a).
Diagnosis: Lindebergia Tuiskunen is a Thorax: Antepronotal lobes meeting
monotypic genus known only for L. bothnica. dorsally,antepronotal3-5;scutaltubercleabsent,
A single adult male was collected from the acrostichals absent; dorsocentralis in two rows,
northern shore ofthe GulfofBothnia, Finland. 8-12 in each row. Scopula thoracalis present;
It is characterised by 13 flagellomeres, sensilla prealarsnotseen,humerals2-4;scutellarsintwo
chaetica on flagellomere 2, 3 and 13. Eyes rows, 5-7 in each row. Preepisternals 7-9;
bare without dorsomedial extension. Palp anepistemals2-3; mediananepistemalIIabsent.
without sensilla clavata. Squamaebare. Pulvilli Wings: Arculus bare, sensilla
small. Pars ventralis present, gonostylus campaniformiapresent, alulapoorly developed.
narrow without crista dorsalis, broad megaseta Costa extending well beyond the tip of R
4+5;
present. subcosta short, reaching the middle ofR R,
2+3;
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NEWDESCRIPTIONS
proximal to Cu R terminates near R R volsella almost tongue shaped, setose. Pars
terminates sligh}t;ly2d+3istal to Cu r-m pr4+o5x;ima4+l5 ventralis verywell developedwith 6-8 marginal
};
to cubital fork; Cu curved sharply (Fig. 2b). setae. Anal point broad, reaching the middle of
2
Legs: Fore femur with a scale at distal gonocoxite. Gonostylus short, folded anteriorly
mm
innermargin; tibiawithasingle spur(0.054 andofpeculiarshape(distalendbroadwithcrista
long), comb absent. Empodium absent, claws dorsalis), distal end rounded and broad. Crista
slightlycurved.Middletibiawithtwospurs,outer dorsalis and megaseta present; megaseta rod
mm mm
spur 0.023 and inner spur 0.019 long. shaped. Paraphallic ratio 2.62.
Pulvilli, arolium and empodium absent. Hind Female Imago: Total body length 2.58
tibialapexwitharowof12-15 strongsetae,each mm, Head length 0.173 mm.
mm
tibia with two spurs, inner 0.020 and outer Antenna: Scape well developed, pedicel
mm
0.054 long (Fig. 2c). covered with microtrichia. Flagellum with five
Malegenitalia:Anteriorendofabdominal flagellomeres, each bearing 3, 4, 6, 5, 8 setae
segment VIII strongly narrow, posterior end respectively.
mm
broad, typically triangular. Anal tergal band Head: Coronalsuturecomplete,0.159
V-type, reaching thebase ofaedeagus. Superior long. Frontal tubercle present, temporal setae
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1
NEWDESCRIPTIONS
FORELEG
Spur
Fig. 2c: Lindebergia kadamtullaensis: <3 Legs (Firstrow: tibial apex, Second row: fifth tarsal)
412 JOURNAL, BOMBAYNATURAL HISTORYSOCIETY, 98(3), DEC 200
NEWDESCRIPTIONS
Fig. 2e: Lindebergia kadamtullaensis: $ Legs (Firstrow: tibial apex, Second row: fifth tarsal)
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NEWDESCRIPTIONS
4-6; eyes bare without dorsal extension. Notum very well developed. Ramus forked at
Maxillarypalpsfive.Tentorialarmtubular,sieve anterior margin of tergite IX, extending
pore absent, stipes narrow, cornua blunt and posteriorlytolabia.CoxostemapodemeS-shaped.
curved. Labiacommashaped,coveredwithmicrotrichia.
Thorax, Wing and Legs: Same as male. Spermathecal duct opens into spermathecal
Female genitalia: Spermatheca single, eminence without anymodification. Gonocoxal
situatedinabdominal segmentVII, almostoval, apodeme straight. Gonapophyis VIII well
with a distinctneck; spermathecal duct straight. developed, dividedintodorsalandventrallobes,
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NEWDESCRIPTIONS
Table2
MEASUREMENTSOFLEGS(INMM)ANDLEGRATIO(LR)OFLINDEBERGIAKADAMTULLAENSIS
Fe Ti Ta Ta, Ta Ta Ta LR
i ? 4 s
p, 0.5527 0.713 0.363 0.218 0.150 0.081 0.072 0.51
p. 0.540 0.577 0.277 0.140 0.104 0.063 0.065 0.48
p; 0.572 0.690 0.395 0.195 0.159 0.077 0.075 0.57
setose.GonocoxiteIXlobeshaped,coveredwith Subfamily: Chironominae
microtrichia. Postgenital plate triangular, bears Tribe: Chironomini
setae. Gonostylus IX not visible, cercus GenusIndoaxarus gen. nov.
flap-shaped, covered with microtrichia and
macrotrichia. Diagnosis: Habitat: Coastal ponds and
Type locality: Kadamtulla seashore, lakes. Medium sized, scape poorly developed,
Middle Andaman; Andaman and Nicobar Is.; eleven flagellomeres, male antenna poorly
India. plumose, frontal tubercle absent, antepronotal
Etymology: Named after the site of lobe bare and fused medially. Squamae bare,
collection, Kadamtulla. sensilla campaniformia present, r-m oblique,
Holotype: 1 9 Kadamtulla, Andaman and cubital fork distal to r-m. Foretibial apex with
Nicobar Is., Coll. G. Maheshwari; deposited in blunt scale, empodium serrated; middle tibial
thecollectionofSchoolofEntomology,St.John’s apexwithtwo combs, eachwithmovable spine.
College, Agra, India. Regn. No. Ch. 22. Anal tergal bands V-type, phallapodeme
Paratypes: 1d,3 9 9,(Regn.No.Ch.22a, subulate, anal point T-shaped, strongly curved
Ch 22b, Ch. 22c and Ch. 22d respectively) data ventrally, superior volsella S-type, inferior
same as holotype. volsellabearingfalciformsetae,medianvolsella
Systematics:Thevalidityofthegenuswas lobe-like. Gonostylusdirectedposteriorly, crista
not certain so far (Tuiskunen 1984). By dorsalis and megaseta absent.
describing one more species, Lindebergia Etymology: Since the material was
kadamtullaensis from the shore ofKadamtulla, collectedfromIndiaandbears close affinitiesto
,
Middle Andaman, from 2 male and 3 female Axarus the genus has been named Indoaxarus.
,
specimens, the genus can be given validity.
L. kadamtullaensis sp. nov. is closely related to Indoaxarussantokhisp. nov.
L. bothnica butcanbe distinguishedby straight (Figs 3a-d)
,
broad gonostylus with crista dorsalis and
rod-shapedmegaseta, pars ventralis long, broad Description:MaleImago:Mediumsized,
anal point and strong triangular abdominal total length 3.017 mm, wing length 2.183 mm,
segment VIII. Female genitalia are described in wing length: wing width 4.56: 3.61.
Antenna: Scape poorly developed;
detail.
Ecology: All specimens were collected flagellumwith11 flagellomeres;flagellumpoorly
fromthe rocky shoreline nearKadamtulla guest plumose;2ndto 10thflagellomeresalmostequal,
house, using Diptera net having a mesh size of distribution ofsetae on flagellomeres, 5-6, 8-9,
50-80|ii. One female was collected using an 9-10,9-11,9-10, 10-11, 10-11, 10-11, 1-9, 9-11,
aspirator. Immature stages ofthe speciesarenot 3-5; ultimate flagellomere with 40-50 bristles.
known. Last flagellomere longer than combined length
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