Studies on taxonomy and distribution of Acridoidea ( Orthoptera ) of Bihar , India

Acknowledgements: We extend our gratitude to the Department of Science & Technology, New Delhi for providing financial assistance during the tenure of a major research project (Ref. No. SR/SO/AS 32/2008) being carried out on Biosystematics and Biodiversity of Acridoidea (Orthoptera) in northern India. Thanks are also due to Prof. Irfan Ahmad, Chairman, Department of Zoology, Aligarh Muslim University, Aligarh for providing necessary facilities.


IntroductIon
Acridoidea is one of the most sought after superfamilies of the order Orthoptera.The order Orthoptera consists of insects with paurometabolous or incomplete metamorphosis, including grasshoppers, crickets and locusts.Many insects in this order produce sound (known as stridulation) by rubbing their wings or their legs against each other, the wings or legs contain rows of corrugated bumps.They are also well adapted for flight since both direct and indirect muscles work together during flight movements thus explaining the reason that these insects can cover long distances during swarming conditions that mainly result from overcrowding and scarcity of food.
Acridoidea is an important Superfamily of the suborder Caelifera (Short-horned Grasshoppers with three segmented tarsi and a short ovipositor), the others are Tridactyloidea, Tetrigoidea and Eumastacoidea.Tetrigoidea is easily distinguishable from Acridoidea by the elongated pronotum, usually extending beyond the end of the body; by the absence of an arolium between the claws and the two-segmented tarsi of the fore and middle legs.The other superfamilies of Caelifera are easily recognizable at sight and are not frequently encountered.Superfamily Acridoidea has shown maximum diversity and divided into various families of which the families Acrididae, Catantopidae and Pyrgomorphidae are widely distributed in India.
Agriculture is the backbone of Bihar's economy employing 81% of the workforce and generating nearly 42% of the State Domestic Product.The percentage of population employed in agriculture in Bihar is much higher than the national average.The gross and net sown area in the state is estimated at 80,000km 2 and 56,000km 2 , respectively.The principal crops are paddy, wheat, pulses, maize, potato, sugarcane, oil seeds, tobacco and jute.Rice, wheat and maize are the major crops.During the survey it was concluded (based on field observation) that at an average, agricultural fields of paddy and wheat have shown maximum infestation of Aiolopus sp.followed by Oxya sp. and Hieroglyphus sp., the grasslands had Spathosternum and Tristria as commonly found genera, shrubs and bushy patches and plantations of pulses mainly arhar were home to Catantops sp., Xenocatantops sp. and Chrotogonous sp. while areas of wild vegetation had Oedipoda, Locusta, Catantops and Eyprepocnemis in common.
If we talk about the field observation it may be concluded that the majority of the areas of southern and southwestern Bihar had more infestation as compared to the northern and northeastern regions of the state.The insects were observed to be less active during the morning and evening hours as compared to the sunlit hours of the day.At dawn hours the concentration of grasshoppers was more in the sunlit patches of the fields and one could rarely find them in shadowed areas.In maize and sugarcane fields especially,their concentration was more above the ground i.e. on plant parts rather than on the ground in grasses, while in the case of vegetables they were more in numbers on the ground in grasses and very few were spotted resting on the plant parts.
In the present study 37 species representing 29 genera belonging to three families, 12 subfamilies and four tribes have been recorded from various regions of Bihar (Table 1).The specimens studied in this work are deposited in the Department of Zoology, Aligarh Muslim University, Uttar Pradesh, India.

MAtErIAL And MEtHodS
About 277 specimens of grasshoppers were collected from various agricultural pastural areas of Bihar and forest habitats.This served as the basis for the present critical study.A complete record was also maintained indicating the reference number, locality, date of collection and name of host plants etc.

(I) collection of adult grasshoppers
The authors surveyed various agricultural areas of Bihar during the period 2009-2010 for the collection of grasshoppers and locusts.They were caught by hand, by forceps, and by the ordinary aerial insect net.The net was used for catching insects individually or by sweeping on grasses, bushes and other vegetables.Since some acridoids live on trees, it is sometimes highly rewarding to investigate the branches of trees.Attempts were made to collect the specimens from their host plants as well as those attracted to light during the night.They were captured on different dates in different months from various crops.Different parts of crops were examined.Attention was also given to fruits and vegetables.The collected specimens were killed in cyanide bottles.

(II) Preparations for morphological studies
Dry mounts were also prepared for better understanding of certain characters like size, colour, texture etc.For this purpose, the specimens were first relaxed, stretched and later they were pinned and labeled properly.Permanent collections of pinned specimens were kept in store boxes and cabinets for further studies on their morphological structures.

(III) Preparations for genitalic studies
For a detailed study of the various components of genitalia, permanent slides were prepared and examined under a microscope in order to conduct a detailed study of the genitalic structures.Drawings were initially made with the help of camera lucida.Details were filled in by conventional microscope examination.
Remarks: The preferred food plant is Calotropis procerca (Ait.) which favour sandy soil and semi-arid conditions.The readiness to accept alternative food plants has enabled Poekilocerus to survive in some areas where Calotropis is scarce or even absent.This is the most mobile member of the genus in which both sexes especially the females have proportionately longer wings.
Natural enemies: The praying mantis Mantis religiosa is a predator and the dipterous parasite Blaesoxipha sp. has been recorded to cause nearly 11% mortality of hoppers.

tribe: chrotogonini Bolivar, 1904 4. Chrotogonus trachypterus (Blanchard, 1836)
Diagnostic characters: Body brown, rugose and tuberculate; head short and broad; antennae 11-segmented; pronotum short, broad with small tubercles; sternum yellowish; tegmina reaching near to the tip of abdomen, covered with numerous prominent nodules, wings nearly as long as the tegmen; hind femur as long as the abdomen; hind tibia with seven external and nine internal spines; abdomen brown above, pale beneath, without darkish spots, but with darkish tinge.
Morphometry: (length in mm).Female: Body 15.0, Tegmina 5.2, Hind femur 6.8, Pronotum 3.25 Remarks: Body colour matches with the soil and can be commonly spotted in ploughed fields and roadside grasses.

B. Family: catantopidae Brunner, 1893
Subfamily: oxyinae Brunner, 1893 5. Oxya japonica japonica (thunberg, 1824) Diagnostic characters: Antennae as long as or slightly longer than head and pronotum together.Lateral longitudinal ridges on ventral surface of female sub genital plate without spines except at apices.Ovipositor valves with short dents.Posterior ventral basivalvular sclerite with a large spine on its inner ventral margin, male cercus with sub-acute or truncate apex.

Oxya hyla hyla (Serville, 1831)
Diagnostic characters: Body of medium size, antennae filiform, longer than, as long as, or shorter than head and pronotum together; fastigium of vertex short, without mid-longitudinal carinula, frontal ridge sulcate, dorsum of pronotum slightly flattened, crossed by three transverse sulci, median carina weak, lateral carinae absent, metazona shorter than prozona, posterior margin rounded or obtusely angular.Ovipositor valves with long hook like dents posterior ventral basivalvular sclerites with very small spinelets on its inner ventral margin.Male circus with subacute or truncate apex.
Material examined: 2 females, 24.x.2010, on grasses, Gopalganj; 1 female, 24.vi.2009, on paddy, Banka;6 females, 20.xi.2010, on paddy, Araria;1 female, 13.vi.2009, on  Diagnostic characters: Green including the antennae.Pronotum smooth with four sulci, narrowly lined with black, the first obsolete above, the second on the sides and the last two continuous.Tegmina subhyaline, densely reticulated and greenish at the base, with green nervures, wings as long as the tegmina, greenish hyaline.The three sub-terminal ventral segments with silky tufts of hair on the middle.Hind tibiae blue with black tipped spines.Antennae with the basal joint yellowish-green, the rest dark green tipped with yellow.
Natural enemies: The authors found small reddish mites possibly Trombidium sp. on adults but doubted whether they caused any mortality.15% of egg pods dug up near Bangalore was parasitized by Scelio hieroglyphi (Basa, 1953).Many vertebrates including frogs, snakes, lizards, birds and mammals occasionally feed on H. banian but none is regarded as an important predator.
Remarks: The specimen was collected from paddy.

Spathosternum prasiniferum (Walker, 1871)
Diagnostic characters: Small, green, integument finely rugose almost smooth.Head conical, fastigium of vertex obtusely angular or parabolic.Filiform antennae, frontal ridge narrow and sulcated.Two broad blackish band or dark greenish-band running behind the lower part of the eyes and below the lateral carinae of the pronotum which is banded above by a narrow pale yellow line and lateral carinae present, Prosternal process large, strongly, antero-posteriorly compressed, spathulated, inclined backwards.
Material Diagnostic characters: This is a typical species of the genus.It can easily be separated from other members of genus in having bluish grey hind tibia with two whitish signs at the base and reddish apex and tarsus, male cercus gradually narrowing towards apex incurved and down curved.Fastigium of vertex round, frontal ridge with characteristic dark brown markings on lateral carinae, prosternal process cylindrical and antero-posteriorly compressed.Elytra and wings fully developed, elytra with numerous brown spots, bluish grey hind tibiae.
Material Diagnostic characters: Reddish-brown, rather stout.Frontal ridge finely punctured, slightly expanded between the antennae, lateral carinae, distinct, slightly divergent, antennae filiform, Pronotum closely punctured, obtusely angulated behind, carina slight, continuous, with the sulci well marked.Abdomen with a short narrow dorsal stripe behind.Hind femora stout, with two transverse black spots above, the first extending into the externo-median area, the lower outer area blackish-brown and the upper carinae slightly serrated, hind tibiae and tarsi red, the former with black tipped spines.Cerci of the male slightly expanded at the tips.The species is easily identified by the cercus which is up curved, more broadened apex and projecting, upper apical angle is more projecting.The species is also easily identified by the character of the hind femur.
Remarks: C. pinguis innotablis is widely distributed in Indian subcontinent and is commonly found in shrubs and herbs.
Distribution: Orissa, Goa, Uttar Pradesh, Tamil Nadu, Bihar.(Kirby, 1910) Diagnosis: Body of medium size, antennae slightly longer or shorter than head and pronotum together, fastigium of vertex with slightly raised carinulae between eyes, median carina never strongly raised, frontal ridge never projecting between antennae, tegmina reaching beyond apex of abdomen, tegmina and wings fully developed, pronotum at least slightly constricted in middle, prosternal process conical.
Natural enemies: This species was found to be parasitized by Eutrombidium trigonum.
Distribution: Very common and known from many localities in India.Sikkim, Kashmir, Himalayas, Assam, Uttar Pradesh, Bihar.

Acrida gigantea (Herbst, 1794)
Diagnostic characters: Head conically ascending.Fastigium broad, laminate and truncate at apex.Transverse sulcus of pronotum present about the middle of pronotal disc.Male subgenital plate comparatively long.Tegmina a little produced beyond the hind knee and wings slightly shorter than tegmina.Lateral carinae with black inner margins.
Remarks: Usually found in paddy and grasses and produces very striking stridulatory sound.
Natural enemies: This species was found to be parasitized by Eutrombidium trigonum.
Remarks: This species occur in sugarcane fields.Natural enemies: No natural enemies have been recorded.
Natural enemies: No natural enemies have been recorded.
Remarks: Commonly found in sugarcane and paddy.
Natural enemies: Red mite Eutrombidium trigonum was observed parasitizing this species.

Aiolopus simulatrix (Walker, 1870)
Diagnostic characters: It is popularly known as Sudan Plague locust and is a serious pest of grain and many other crops.The species is variable in general coloration, size, relative length of tegmina and width of hind femur.It can easily be distinguished by its broad hind femur which is longer than hind tibia and by the form of frontal ridge and pronotum.

Aiolopus thalassinus thalassinus (Fabricius, 1781)
Diagnostic characters: Medium sized insect, tegmina and wings fully developed, head acutely conical, antennae filiform, as long as or longer than head and pronotum together, fastigium of vertex elongateangular, slightly concave, with well developed lateral carinulae, frons oblique; frontal ridge flat, pronotum slightly tectiform and slightly constricted in prozona, median carina weak, medial area of tegmen with intercalary vein well developed and finely serrated, hind femur slender, hind tibia with inner pair of spines longer than external one, external apical spine absent, arolium of small size, Frontal ridge of uniform width with nearly parallel margins, foveolae shorter, hind tibia coloured as in tumulus but with a dark ring before the middle and without the bluish median part.
Natural enemies: Red mite identified as Eutrombidium trigonum was found to infect the insect.

Aiolopus thalassinus tamulus (Fabricius, 1798)
Diagnostic characters: Coloured in combination of black and green.Frontal ridge gradually tapered towards the fastigium, foveolae longer, hind tibia in the basal third with a straw-coloured band, in the median part usually bluish, the apical part reddish.
Remarks: Common in paddy fields but may also be encountered in wheat, maize, and grassland areas surrounding the fields.

Chloebora grossa (Saussure, 1884)
Diagnostic characters: Large sized insect with nearly round eyes, Median carina well developed but lateral carinae show slight presence in metazona, tegmina membranous at apical one third part, hind wing membranous and bears a complete fascia midway, hind tibia is markedly shorter than femur.

Oedaleus senegalensis (Krauss, 1877)
Diagnostic characters: A characteristic X mark on the Pronotum, which is broadly rounded posteriorly.Hind wing, yellow basally with complete dark fascia.
Morphometry: (length in mm Diagnostic characters: Colour variable, green, testacious or brown.Antennae sub depressed, longer than the head and pronotum together.Pronotum with transverse sulcus placed about the middle, the head not carinated above, the pronotum strongly tricarinate, the median carina slightly raised, the lateral carinae slightly incurved before the middle and then diverging.Tegmina longer than abdomen in a male usually shorter in the female, sometimes with longitudinal yellow scapular lines.Wings hyaline with brown nervures.Pectus and front leg pilose, legs not spotted, hind tibia with twelve small spines, decreasing in size towards the base.Subgenital plate in the male is curved, pubescent, valves of the ovipositor unarmed.
Remarks: It is a large species other than those already recorded.It may well become minor pests at times.
Natural enemies: No natural enemies have been recorded.

Leva indica (I. Bolivar, 1902)
Diagnostic characters: Testacious varied with brown faveolae of the vertex subquadrate, filled up with black frontal carina impress punctuate, sulcate at the ocellus for a large space in the male, a short space in the female.Antennae filiform, slightly depressed.Pronotum pale above.Tegmina subhyaline with a yellow spacular line and brown discoid spots.Hind femora with four brown bands, often obsolete on the outer side.
Remarks: It is very small species.Lateral carinae of pronotum parallel in prozona and strongly divergent in metazona which is the most characteristic feature of the species.Abundantly found on grasses and paddy crops.

Leionotacris bolivari (uvarov, 1921)
Diagnostic characters: Frontal ridge convex; fastigial foveolae elongate rhomboidal, dorsum of head and pronotum with a pale stripe extending from anterior margin of fastigium to posterior margin of pronotum with posterior transverse sulcus placed in the middle, tegmina perfectly developed at least reaching tip of hind femur with three dark spots on radial area.
Remarks: This species has been recorded as a minor pest on the foliage of teak in India.
Natural enemies: No natural enemies have been recorded.

Oxya fuscovittata (Marschall, 1836)
paddy, Sarsaram, Rohtas.Morphometry: (length in mm).Female: Body 13.8, Tegmina 22.2, Hind femur 13.4,Pronotum 8.2.Remarks: Reputed pest of paddy.Natural enemies: No natural enemies recorded.Diagnostic characters: Posterior margin of female subgenital plate almost straight and smooth.Male supra anal plate with a tubercles on each side of median apical process, cercus laterally much compressed and of uniform width.Posterior ventral basivalvular sclerites of ovipositor without any well defined spines on its lower inner margin.Median pair of spines on posterior margin of subgenital plate set wider apart.

33. Locusta migratoria (Linnaeus, 1758)
Wings mostly rugose so the dark band often pale brown, strongly bowed reaching upto IXth or Xth section of anal fan and not touching hind margin(Harz 1975).Integument often less rugose and less callous.Facial carinula mostly without projections.Dark fasciae of wings extending towards the base by one longitudinal band into the anterior field.Diagnostic characters: It occurs in green and brown form in the solitary phase.The species can easily be identified from other Locusts by the absence of prosternal process, the slight yellow tinting of the wings and the black anal veins are distinctive features of the species. Subfamily: