ON A COLLECTION OF MEMBRACIDS (HOMOPTERA : MEMBRACIDAE) FROM CALCUTTA AND ITS ENVIRONS

The membracidae constitutes one of the most distinct families in the Homoptera. These iQsects are chiefly distinguished by the great development of the pronotum, particularly its pronotal processes. The group may be diagnosed by its primary characters viz., Ocelli placed between the eyes; antennae inserted infront of head and between eyes; pronotum prolonged backward into a hood or process of variable form. The membracids, commonly known as tree hoppers, are homopteran insects which suck the plant sap from the shrubs and trees with the help of their piercing and sucking type of rostrum. They are also found in open fields on various weeds, grasses and similar perennial plants upon which they feed. The group is also economically important. The eggs are laid in the slits of epidermis of short shoot in double rows. Nymphs live in the same colony and in the same shoot along with parents. 2-5 generations per year have been observed in India. Ananthasubramanian and Ananthakrishnan (1975) have dealt with the biology of this grou p.


INTRODUCTION
The membracidae constitutes one of the most distinct families in the Homoptera.These iQsects are chiefly distinguished by the great development of the pronotum, particularly its pronotal processes.The group may be diagnosed by its primary characters viz., Ocelli placed between the eyes; antennae inserted infront of head and between eyes; pronotum prolonged backward into a hood or process of variable form.
The membracids, commonly known as tree hoppers, are homopteran insects which suck the plant sap from the shrubs and trees with the help of their piercing and sucking type of rostrum.They are also found in open fields on various weeds, grasses and similar perennial plants upon which they feed.The group is also economically important.
The eggs are laid in the slits of epidermis of short shoot in double rows.Nymphs live in the same colony and in the same shoot along with parents.2-5 generations per year have been observed in India.Ananthasubramanian and Ananthakrishnan (1975) have dealt with the biology of this grou p.
Literature reveals that a little over 200 species belonging to 45 genera are known so far from the Indian subcontinent, of which, 80 species are recorded from North-east India, and 50 species from West Bengal (22 species from Calcutta).
The present paper provides the first consolidated account of 14 species belonging to 7 genera of membracids of Calcutta.It is based IS Record8 of tke ZoologioaZ Survey oJ 1 nala on the available collections represented in the Zoological Survey of India,.Calcutta.
The paper includes the generic description with original reference, synonymy, if any, and the subsequent references, diagnostic morphological features, taxonomic & biological remarks, if any, distributional records under each species and a running key to various taxa for easy identification of the insects.

SYSTEMATIC ACCOUNT
Subfamily OXYRHACHINAE Haupt, 1929Tribe Oxyrhachini Distant, 1908 Genus Oxyrhachis Germer, 1835 Tribe Ox"rhachini Distant Head wider than long; posterior pronotal process long and narrow, broad at base, extending beyond posterior angle of inner margin of tegmina; wings with 3 or 4 apical cells; tibiae dilated; sides of the pro-and mesonotum are armed with a small10be or tooth.
. Head wider than long; mouth 'a little elevated; eyes large and glob ate ; ocelli equidistant from each ~other and located above the centro-ocular line; pronotum with the lateral angles.more or less produced; posterior process tricarinate, long, narro\v, broad at base, with or without a ventral carina or keel on apical half; wings with 3 or 4 apical cells and tegmina ~ith 5 apical and 3 discoidal cells.
Remark: The genus is predominant in Oriental and Ethiopian regions.Head frontally piceous, vertex of head nearly twice as wide as long, sparsely covered with hairs; ocelli equi-distant from each other and located on centro ocular line; pronotum with•a central longitudinal carination which traverses the length of the posterior process; Posterior process extending beyond the tips of tegmina, upwardly recurved, beneath laminately ampliate and finely serrat~; tegmina dull hyaline, the veins fuscous; legs pilose.Calcutta, 11.xii.1965, Coli. ?Rem.ark:This is a very common species abundantly found throughout India including Calcutta where it is recorded in good numbers during September and February.This species is predominant in south India but rather rare in western India.The species can easily be recognised by its large size, dark brown colour and thickly punctate body.1851. Oa;yrhachis rufeseens Walker, List. H01n., ii : 506. 1851. Oa;yrhachis rudis Walker, List. Hom., ii : 509. 1908. Oxyrhaehis rufescens : Distant, Fauna Brit. India. 6 : 146. 1975.Oxyrhachis rufeseens: Ananthasubramanian and Ananthakrishnan,Ree. zool. Surv. India,68 : 171.Head twice as broad as long; vertex sinuate, punctate with short silvery hairs; apical areas of posterior process slightly elevated; ocelli convex, closer than from eyes and located above centro-ocular line; Pronotum thickly punctate; anterior carina dark reddish brown; directed outwards, then backwards; lateral carina nearly straight; dorso posterior carina curved forward and outwards joining anterior carina in narrow curve; posterior process moderately laminately gibbous at base, apically upturned, just rea,ching tegminal apex; legs testaceous; abdomen dark reddish brown above, greyish tomentose below.

Oxyrhacbis rufescens Walker
M ateriaZ examined: 1 example.INDIA; West Bengal, Calcutta, 29.i.1907, Call. ?Remark: The species is also widely distributed throughout India.In Calcutta it is recorded in the month of May.Head vertical, upper margin of vertex arcuate and sinuate; eyes hemispherical; ocelli closer to eyes; pronotum with anteriorly produced transverse processes; posterior process slender, tricarinate, well separated from the scutellum and abdomen; scutellum triangular about as wide as long, apex emarginate; tegmina without pterostigma, with five apical cells and two discoidal cells; hind wing with 4 apical cells; tibiae simple.

Remark;
The genus is predominant in oriental and Ethiopian region and abundantly found in South and Eastern India in comparison to Western India.Head about thrice as broad as long; vertex ,arcuate and sinuate j eyes black directed laterad; suprahumerals moderately developed, gently curved; ocelli slightly closer to eyes than to each other; pronotum black, strongly punctate; posterior process tricarinate, strongly, convexly recurved from near apex, achieving its maximum height above scutellum, then moderately arched, tip acute, touching the posterior end of 5th apical cell; scutellum black, as broad as long, tip broadly emarginate ; tegmina ochraceous, black on costal margin and apical lim~us, hindwing with 4 apical cells; legs with tarsi yellowish.: Distant,Fauna Brit. India, Head about three times wider than long; basal margin of vertex convex; ocelli black, nearer to eyes than to each other; pronotum black; posterior pro notal process slightly arched at base and more obliquely straight; posterior process tricarinate above; lateral transverse processes less prominently recurved and their apices less acute; scutellum and sternal lateral margins chalky white and silky; tibiae reddish brown.Inaia, Head three times wider than long; basal margin of vertex, lateral margins obliquely sloping downwards, ocelli black, nearer to eyes than to each other; suprahumerals robust, strongly curved; pronotum black, thickly punctate; posterior process strongly tricarinate above, abruptly elevated from near base passing beyond 5th apical cell, apex black; tegmina pale bronzy, ochraceous, base and apical half of costal margin black, three and a half times longer ,than wid~; hind wing with 4 apical cells; scutellum as broad as long, tip narrowly emarginate ; tibiae reddish brown.
. Scutellu'm normal and exposed"; hind wings wit~ three apical cells; a distinct pterostignla may be present or absent; frontoclypeal lobes either partially or completely fused to the frontoclypeus on their inner margins.Hind trochanters elevated into a disc inwardly, armed with ~pines.
Remark: The genus is predominant in oriental and Ethiopian regions.

Key to speoie8 of Tricentrus Stal
Lateral processes of pronotum longer; apex of posterior process about reaching the posterior anglo of inner margin of tegmina, scutellum with a small pale sericeous spot at eaoh basal angle; body shorter Lateral proces-;es of pronotuln rather short ; apex of posterior process projecting, not impinging on teglniu!t and not reaching the posterior a ngle of inner margin of tegmi na ; scutellum withoub such spvt; body rather longer Head about 3 times wider across extremities of eyes than length of ., vertex which is about twice as wide as long, ocelli nearer to eyes than to each other,'pronotum punctate, ochraceously pilose, lateral processes• straight, obliquely porect, centrally ridged; posteior proce~s robust, carinate; central carination continued through pronotum, closely impinging on tegmina.Each: basal angle of scutellum with a small pale seri-.ceous spot, tegmina springled with pilosi~y, piceous and punctate at• base, apical margin, a little paler and ochraceous brown, femora and claws black, apices of femora and the whole of the tibiae castaneous, tarsi ochraceous.Head about two and a half times.wider than long, upper margin of vertex arcuate and sinuate, ocelli ne~ret to eyes than to each other" pronotum black, thickly punctate; lateral processes very short, 1;>road, recurved, anterior margin rounded,' posterior margin almost 'straight, apex roundly subtruncate, posterior process also short, robust, central and lateral carinatlon fine, apex projecting, tegmina punctate on bhick basal area.with a pale bronzy tint, the veins piceous, legs black, somewhat longly pilosE!.Type-species: Cicada genistae Fabricius Head about two and a half times as wide as long, vertex nearly one and a half times wider than long; eyes subglobate, pronotum low, posterior process broadly triangular, closely fitting against scutellum, contiguous with tegmina,; scutellum triangular deeply excavated at tip, wider than long, incompletely chitinised in middle, tegmina two and a half times longer than wide with 5 apical cells and 2 discoidal cells; hind wings with 3apical cells; posterior trochanters without spinules.
Remarks: This genus closely resembles Tricentru8 Steil, but differs by the unarmed lateral angle~ of the pronotum and by the absence of spinnules to the posterior trochanters.
Di8tribution.: This genus is known from Palaearctic, Ethiopian, Oriental, Malayan and some portions of Australasian Regions.It is commonly found in Southern India.Head about two and a half t~mes wider across extremities of eyes tha~ leJ;1gth of yertex j v'ertex p:early one and a half times• ' .wider than long, Qcelll slightly 'closer to eyes.than to each other; pronotum black, very thickly,.,-•so~ewhat finely p~nctate, t~e Iate~.alangles subacutely 'pI:oniinent t .' 'finely ca~inate,.scutellum ~ider than long,.triangular, exc~'vated at tip, the posterior process slender, unicolorous, only just rea~hing the poste~ior ,a~gle of the inner tegminal margin, tegmina, grayish opaque, the basal area black, the apical area much crowded with fuscous brown, femora black, tarsi ochraceous.gradually narrowed behind the slightly dominant lateral angles and gradually passing into the posterior process, scutellum aborted in the middle", apices spine-like; tegmina short not extending beyond abdominal apex, gradually somewhat amplified towards apex, wirh 5 apical cells and 2 or 3 discoidal cells, hind wings with a 3 apical cells.
Body small, obovate, black; head about two and a half times as long; eyes deflexed, front elevated, ocelli about twice as far apart from each other as from the eyes, pronotum strongly tuberculous, ridged and moderately arched, obtusely "angulate before the base of the posterior process, concave at base and convexly, laminately produced before apex, the central ridge finely tuberculous; tegmina more or less finely tuberculous variably coloured; legs piceous, tarsi ochraceous.

SUMMARY
The paper sets out to provide a first comprehensive account on the' systematics of the family Membracidae from Calcutta and its environs.It incorporates 14 species under 6 genera belonging to 5 tribes distributed over 2 subfamilies.Tribal, Generic and Specific diagnoses have also been included.Besides, running keys for the subfamilies, tribes, genera and species have been provided.List of synonymies, wherever, necessary and notes on the geographical distribution have also been given for the taxa.Literature relevant to the present contribution have been furnished under references.
wider than long; ocelli nearly equidistant from each other and from eyes; pronotum moderately high; posterior process emerging dorsally, horizontally from behind disc not arcute, slightly sinuate; scutellum triangular, wider than long; tegmina about three times as long as wide with 5 apical and 2 discoidal cells; hind wings with 4 The genus is predominant in Ethiopian & Oriental region.It is widely distributed in Western and Southern India and also known from some parts of Northern India.
Key to the species ofGargara Amyot & Serville Rec.ortls of the Zoologic~Z 8'UffJell of Indi~ 2 (1) Posterior process just rep,cblng apex ~f C1a~al area 1 (2) Posterior process just passing apex of claval area, centrally and la.terally carinate .-. 'fobusta Distant lOS includes 5 species from India, Of these, two species 'Vi~., O. minutu8 (Fabr.)and O. decoloratu8 Distant ~re reported from Calcutta.The genus is predominant i'n Oriental and Ethiopian regions.It is found in Sou~hern and Eastern India including Calcutta but it rarely occurs.inWestern and Northern India.
INDIA: West Bengal, Calcutta Maidan, 27.iv.1911,F. H. Gravelti CoIl •.The species can' ~e recognised by its minute size and black colour.:This is an uncommon 'species f9und in India.It usually Head about two and a half times wider than long.Ocelli nearer to eyes than to each other; pronotum black -with large tubercles and granules; posterior process broadly triangular, a little elevated behind disc, tegmina about 2.5 times longer than wide, punctate and black, • veins more or less infascate, apical area tinted with reddish brown patches; hind wing with 3 apical cells, legs moderate, tibiae prismatic; anterior trochenters unarmed within.Material examined: 1 example.INDIA: West Bepgal, Calcutta, 7.vlii.1914,ColI.?Re,"!,ark:The species is common in South India and rather rare in West Bengal including Calcutta where it is recorded as early as 1914. ".R.emar1c: