Plate I. Frontispiece. EXPLANATION OF PLATE I. Fic. 1.—Nymphs of the Jola Grasshopper (Colemanta sphenarioides, Bol.) feeding on a young plant of jola (Andropogon sorghum, 1.) Fic. 2.—Top of an almost mature jola plant showing damage done to leaf and head. An adult male grasshopper is feeding on the head. Fic. 3.—Nymph of the third instar showing colour variation, greenish, tinged here and there with red. Fia. 4.—Adult female grasshopper laying eggs. ‘us Degait a wihA— + art ENTOMOLOGICAL SERIES—BULLETIN No. 2 DEPARTMENT OF AGRICULTURE MYSORE STATE TELE) JO Ar Ee Ori’, Cok N G oS EiOwe HR (Colemanita sphenartotdes, Bol.) BY LB Sab 3. sCsOeL ENEAIN: “MieAn PHD. Mycologist and Entomologist to the Government of Mysore BANGALORE: PRINTED AT THE GOVERNMENT PRESS ils Lat - pene ss ee, &3 * , - t. p ; ?. 7 ry : ad f > % wert)”. . ty we a * ve i ey oi ae > ae * ‘ 7 : ve - ‘ A 0 a =a) hes a tre FOREWORD. —_—#—— Tuts bulletin aims to give as complete information as possible about a very serious insect pest. As the pest isa new one, and as practically nothing has been published with regard to it, I have thought it wise to give a detailed scientific description of the insect and a full account of its life-history, in addition to the discussion of what are com- ~monly but erroneously considered more practical matters. A popular account is being prepared for issue as a Kana- rese bulletin. The facts, as here given, are the results of observations and experiments extending over about two years. In this connection, I wish to express my appreciation of the effi- clent service rendered by B. C. Shantappa, formerly Field- man but now Agricultural Inspector in this Department, in the carrying out of practical measures planned by me. The coloured plates are from paintings made by M. Ranganayakalu, Artist of this Department. All photo- graphs as well as the original drawings for most of the other figures were made by the author. In conclusion, | wish to express my thanks to Mr. C. H. Yates, Superintendent, Government Press, for the great care he has taken in the printing of text and plates. BANGALORE, LEsLIg C. CoLEMAN. June 1911. CON TEN ES. —__—_4—_——_— Previous publications on the subject Technical description Character of damage Life history of the Jola Caan auee Distribution of the Jola Grasshopper Causes for unequal distribution of the grasshopper Effect of weather upon the grasshopper and upon the eggs Natural enemies of the Jola Grasshopper Means of combating the Jola Grasshopper General conclusions Explanation of plates bo w wo wo wb bo aon oe q= — Sarna : ty i 5) ree THE JOLA OR DECCAN GRASSHOPPER (Colemanta sphenarioides, Bol.) THE Deccan Grasshopper is a new and serious agricultural pest in Mysore. It is to be considered serious not only on account of the damage it has already done in the areas where it has gained a footing, but also on account of its possibilities for the future. So recent is this pest that practically nothing has, as yet, been published with regard to it. The first printed reference to it occurs in a note by Mr. Maxwell Lefroy, Imperial Entomologist, published in the Journal of the Bombay Natural History Society, Vol. XIX, No. 4, 1910, p. 1007. In this note, he suggests that the popular name ‘‘ Deccan Grasshopper” be applied to the insect as indicating its habitat. This name is, on the whole, a suitable one, although this grasshopper appears to occupy but a fraction of the area known as the Deccan. In Mysore, it would be, perhaps, better known as the Jola Grasshopper, for here it occurs, as yet, only in those areas where jola (Andropogon sorghum) is the staple cereal crop and it is, therefore, to this crop that the most extensive damage is done. In April 1910, specimens of this grasshopper, collected the previous year in the neighbourhood of Honnali, Shimoga District, were sent to Prof. Ignacio Bolivar, one of the leading authorities on Orthoptera, for identification. He informed me that this form is not only a new species but also belongs to a new genus. Later, in the Boletin de la Real Sociedad Espaiola de Historia Natural, p. 319, July 1910, he published his descriptions of the genus and species. As his paper, which was written in Spanish, appeared in a Spanish scientific journal not easily acces- sible to entomological workers in India, I published a note giving its main points, together with his original B 2 THE JOLA OR DECCAN GRASSHOPPER Latin descriptions in full, in the Journal of the Bombay Natural History Society, Vol. XX, No. 3, p. 879, 1911. These are the only scientific communications that have, as yet, appeared. In addition to the above, extracts from a letter written by me containing some practical suggestions with regard to combating this pest, were published, by order of the Mysore Government, in the Mysore Gazette, Vol. 46, pp. 184 and 185 of 16th February 1911 and p. 200 of 23rd February 1911. These extracts were accompanied by photographs showing damage done by the pest as well as the results of combative measures. Mention of this pest is also made in the annual reports of the Agricultural Departments of Bombay and Madras for 1910. Bolivar’s original descriptions translated into English are as follows :— Colemania, gen. nov.—Body elongate, subcylindrical, in the male strongly fusiform, arched in the middle. Head conical. Fastigium elongate with a distinct median furrow above, produced horizontally, anteriorly obtusely rounded, longer than the eye. Frons_ strongly reclinate, subsinuate in outline. Antenne — -? with cylindrical base. Frontal costa sulcate throughout, somewhat compressed at the base, slightly depressed but quite distinct, becoming obsolete before the epistoma. Lateral carine of the frons sinuate, diverging somewhat anteriorly. Cheeks marked by a feeble but distinct granular line. Eyes small, little longer than broad, truncate posteriorly ; ocelli not prominent, median ocellus between, basal ocelli in front of, the eyes. Pronotum conical, especially in males, in females almost cylindrical, with obtusely sinuate posterior border; sulci obsolete above; posterior transverse sulcus (sulcus typicus) traverses pronotum far behind the middle. Lateral lobes of pronotum elongate, margin entire, anterior margin oblique, inferior straight, posterior indistinctly sinuate, anterior angle obtuse, posterior approximately right. Elytra very narrow, linear, elongate, longer than the pronotum. Wings absent. Prosternum provided with a very acute aciculate tubercle; meso- sternal lobes elongate, truncate posteriorly, approximated in the male, in the female with space ampliated anteriorly; posterior angle rounded. Metasternal foveol in both male and female close together. Legs short, anterior femora in males incrassate, posterior femora slender; external median area narrow, with pinnate markings rather indistinct; geniculate lobe produced into an angle. Posterior tibize slender, in apical third somewhat ampliated and flattened above, armed internally with 11, externally with 9 spines. Posterior tarsi slender, first seg- ment twice as long as the second. Abdomen cylindrical. Apex not at all clavate. Final segment in the male transverse, posteriorly trisinuate. Supra-anal lamina elongate, triangular, longer than the cerci, sulcate, acute, in female almost equilateral ; cerci short, curved with almost subulate tip, in female minute and straight. Subgenital TECHNICAL DESCRIPTION 3 lamina compressed, with a compressed carina posteriorly. Valves of the ovipositor short, sinuate. Colemania sphenarioides, sp. nov.—Ground colour straw or yellow. Head behind the eyes with a broad purplish fascia and a yellowish band which extends from the antennsz to the anterior angle of the pronotum. Frons purplish. Vertex convex with a blue-black median line which is wider in front of the eyes. Antenne with first segment pallid, the succeeding ones blue-black marked with a longitudinal pallid fascia beneath. Pronotum dorsally rufescent, latero-dorsally with a yellow fascia which is marked on the inner border with a black line; lateral lobes callous, punctate and marked with three fascie ; superior fascia red, median fascia black, inferior fascia yellow; inferior margin slightly sinuate. Meso- and metanotum in males strongly in- crassate, dorsum smooth, sides with a continuation of the prothoracic fascie ; external fascia strongly punctate. Elytra towards the apex slightly ampliated, extending to the posterior border of the first ab- dominal segment, rufescent with paler veins. Legs pallid. Posterior tibiz rufescent, armed with pallid spines which are black at the apex. Abdomen pallid dorsally, laterally with fuscous and grey patches. First segment provided with a tympanum. Measurements of male :— Body length ... d io Oo) em. From eye to apex of rial ‘See E Pronotum Ae fae bee Giaor 3 Elytron nee Soe Mes Oro aus Posterior femur m2 Poa A its} pe Measurements of female :— Body length ... : oy ole rs From eye to apex of head aes TSM Ge Pronotum ee ee fase 6 a Elytron a ne til 6'o5 4s Posterior fenine nee Bee gy x Loeality, Honnali, 6-10-09. Collectors, L. C. Coleman and K. Kunhi Kannan. The above description is, in one or two respects, imperfect. The specimens were received by Prof. Bolivar somewhat damaged, with the result that the structure of the antenne could not be made out. The antenne ditfer somewhat in the two sexes. In both sexes, they have usually eighteen segments, but there is variation in ‘this respect An examination of twenty females showed seven- teen with eighteen segments and three with only seventeen segments. Anexamination of ten males revealed five with eighteen segments and five in which the third segment from the base showed a very distinct, though apparently not complete, division into two. This would give nineteen segments, but, as already stated, the division is not quite B 2 4 complete. ABDOMEN aS — oe Meeriuius PROTHORAH MESOTHORAX N THE JOLA OR DECCAN GRASSHOPPER We must, thus, give the number of segments ‘ s - TROCHANTER 4 ’ fEmuR? TIBIA mt T&ésus—-- - — ae pci, Il. 40h: Outline of female of Colemania sphenarioides, Bol. dissected to show the various external features. The elytron or wing- cover is removed and only the base of the hind leg is shown. as varying from seventeen to nineteen. The antenne are thick- est at about the third seg- ment and taper from here eradually to the end. In the female, segments 3-8 have in section a triangular form which is particularly marked in segments 3-5. The more distal segments cradually change to a cy- lindrical shape. In the males, this triangular shape of the segments is usually not nearly so distinct, be- ing marked usually only on seements 3 and 4. Plate X, Figs. 1 and 2 show these differences in structure. The antenne of the female is marked on the lower angle with a narrow yellow band extending to the 8th segment. In the male this band is, at least usually, absent. Another feature which commonly varies shehtly from the descrip- tion given by Bolivar is the colour of the hind tibie. While some — specimens have the hind tibiz reddish throughout, in the majority of cases the basal half of the tibia is flavescent, only the apical half being red- dish.’ Bolivar’ places this form in his section Orthacres, 1 Those unfamiliar with the external structure of a grasshopper should consult Text-fig. 1 in which are indicated the main external features. 2 Bolivar, Pyrgomorphine, Genera Insectorum Fasc. 90, p. 44, 1909. CHARACTER OF DAMAGE 5 subfamily Pyrgomorphine and close to the genus Orthacris itself. Its chief distinguishing feature is the enlargement of the thoracic region especially in the males. While this fusiform shape of the body is much more marked in the male than in the female, still it is quite distinct in the latter also, especially if the specimen is viewed from above. This insect is not at all difficult to recognise and 1s not likely to be mistaken for any other form occurring in the infested regions. Its most striking feature is the total absence of wings and the great reduction in size in the wing covers or elytra. Only one other insect has been found by me in the affected area that might be mistaken for it. This isa species of Orthacris which, of course, also lacks wings but is hardly more than half as large as Colemania sphenarioides. This form has been found in small numbers in grass lands and on grassy strips border- ing fields in the neighbourhood of Honnali. It has, how- ever, never been seen to attack crops of any kind. It has more than one brood or generation in a year and so is to be found in the adult state at various different seasons. It may be noted here that the nymphs of this form bear a decided resemblance to those of Colemania sphenarioides and might be mistaken for the latter. . CHARACTER OF DAMAGE. The chief damage caused by Colemania sphenarioides in Mysore is, as already stated, to jola. It, however, seems to attack all other dry land cereals cultivated in the neighbourhood, such as navane (Setaria italica), sajje (Pennisetum typhoidium), savé (Panicum miliare) and ragi (Hleusine coracana) with equal severity. Jola (Andropogon sorghum) however forms the staple cereal of the infested regions and the damage to it is much more marked. Besides cereals, this form also attacks various puise crops such as green gram (Phaseolus mungo), black gram (Phaseolus mungo, var. radiatus) and avare (Dolichos lab- lab) grown in the infested area. It also feeds upon pigeon pea or togari (Cajanus indicus) to a certain extent. In ad- dition it can occasionally be found feeding on chillies (Capst- cum spp.) eating both the leaves and the fruits. The damage 6 THE JOLA OR DECCAN GRASSHOPPER to all these crops is, however, much less severe than that to the cereals mentioned above. It appears likely that it may feed to a slight extent on cotton also, but the damage to this crop has, up to the present, been quite negligible. The insects can, of course, be found in considerable num- bers on all these crops where they occur in infested areas and this leads the raiyats to suppose that the crops are be- ing seriously injured. This applies especially to cotton, chillies and togari, all of which are present in the fields in considerable quantity at the time of jola harvest. A careful examination, however, shows that very little actual feeding is taking place, most of the insects simply copulating or ‘resting on the plants. Avare, green gram, black gram and pigeon pea earlier in the season are more severely attacked. The damage to the pulses consists in the eating of the leaves and How ers; in no case have any pods or seeds been found eaten by this grasshopper. On the other hand, in the case of all the cereals mentioned, not only are the leaves eaten but also the grains in the heads, the result being that in a severely attacked field practically nothing is left but the stalks or stems of the plants and the empty ears. Plate V, Fig. 1 shows a field of jola which has been almost completely destroyed in this way. All that is left of the leaves are the stiff and hard midribs which stand out like needles from the stalks. Plate III, Fig. 2 shows the effect produced upon a head of jola. In this | particular case, almost every grain has been eaten. A few grains, ly- ing more or less hidden by the outer branchlets of the head, have been left while one grain is half eaten and thus shows up strongly with its white eaten surface against the dark background. Plate III, Fig. 1 shows a healthy head for comparison. ‘These two heads were photographed to about the same scale and a comparison of them reveals the fact that, in the case of the attacked plant, the erowth of both head and stalk has been creatly stunted. This i is, of course, due to the fact that the plant has been stripped of leaves and so has been unable to develop normally. In the infested areas the soil is mainly of two types, viz., the ordinary black cotton soil of the Deccan and red laterite soil. As a general rule the infestation on the black soil areas has been much more severe than that on LIFE HISTORY i the red soil’. However, this contrast is in certain locali- ties being obliterated and the infestation 1s gradually spreading out on to the red soil areas also. There seems no a priort reason why black soil areas should be worse in- fested, unless it is the fact that oviposition is decidedly more difficult in the red soil. This point will be touched on later. The possibility of the two types of soil producing plants which will be eaten by the grasshoppers with dif- ferent degrees of avidity (a view commonly held by raiyats) cannot be entertained. LIFE HISTORY OF THE JOLA GRASSHOPPER. The life history of the Jola Grasshopper is, in general, as follows:—The eggs hatch in July after the early monsoon rains have fallen. The young hoppers begin feeding upon the grass at the borders of the fields and up- on the young crops, if they have already come up. Growth continues throughout July, August and September, the erasshoppers assuming the adult form late in October and November. Copulation takes place soon after the adult form is reached and shortly after this, egg-laying begins. This continues through November and into December, during which time the insects are particularly lethargic and very little feeding is done. By the end of December, most of the insects are dead, although a few may be found alive as late as January. The eggs remain in the soil till the following monsoon, when the young hoppers hatch and begin their work of destruction again. Let us now examine more closely the individual stages of the life history. Egg-laying.—As already stated, the worst infestation in the infected areas in Mysore is to be found in crops grown on black soil and it is here that the greatest num- ber of egg-masses are laid. The grasshoppers seem to have no “preference for particular parts of a field or for 1 This dacs not appear to hold universally. Ina mate eel nS Mr. ae arson dra Rao, Assistant in Entomology, on this pest in Bellary District, and kindly furnished to me by Dr. C. A. Barber, Botanist tothe Madras Government, the author states :— “The hopper is equally severe in both black and red soils, but, as far as observed, more harm is done in red soils, as here the eggs hatch out earlier.”” As already stated, this does not agree with observations made in Mysore. Information received from Mr. M. L. Kulkarni, ‘Divisional Inspector of Agriculture, Bombay, indicates that in Dharwar Dis- trict the infestation is worse on black than on red soil areas. 8 THE JOLA OR DECCAN GRASSHOPPER the grassy strips bordering them. Egg-laying, however, takes place most commonly in those places where the soil is most easily penetrated. The result is that, in the fields, the great majority of burrows are made in the bottoms or sides of the cracks which are so abundant in black soil at this time of the year. Through these cracks the grasshop- per is able to get down into those portions of the soil which still retain a fair amount of moisture much more readily than they could by boring directly down through the top. Other favorite spots are the demarcation mounds which are freshly heaped up every year and on which numerous cracks develop. The egg-laying on grassy strips and patches seems, on the whole, to be much less general, for here the soil is very hard and the cracks are comparatively few in number. Not infrequently egg-laying takes place at the bases of the numerous bushes, especially tangadi (Cassa auriculata), found scattered over grassy areas. Here too, the female grasshopper can more easily burrow down into the soil. On red soil areas, comparatively few cases of oviposi- tion have been observed and these have been observed in- variably at the bases of plants growing in the fields. Thus a number of females were observed burrowing at the bases of pigeon pea (Cajanus indicus) plants, the ‘posterior end of the body being thrust down close to the base of the stem. ‘I'he upper layers of the red soil are, at this time of the year, extremely hard so that boring would be a very difficult matter for such a comparatively feeble insect as this grasshopper. No cases of oviposition in red soil outside of those mentioned have as yet been observed. The process of burrowing is very similar to that occurring in the case of other erasshoppers. A striking feature is, however, the position which the grasshopper occupies during the process. ‘The abdomen is thrust down in a slightly oblique to almost perpendicular direc- tion. There is practically no bending of the abdomen, the whole body being kept almost in a straight line. In cases where the boring takes place in cracks of the soil, when the body is sunk to the full depth, it may lie almost com- pletely in the crack below the surface of the soil, the antenne alone projecting above the surface. The hind legs are drawn up so that the femora touch the body while, in turn, the tibiz are closely approximated to them. The THE PROCESS OF EGG-LAYING 9 bases of the hind femora are sunk into the burrow, while the middle pair of legs he at its mouth ; ibabxneiae, Oe Ovipositors of Jola Grasshopper, show- ing action during digging; a, anal cercus ; b, dorsal ovipositor ; c, ventral ovipositor ; d, furcula vulvalis; e, ovipositors closed. the front legs may touch the ground but more commonly they pro- ject freely into the air. Plate I, Fig. 4 and Plate VII, Fig. 1 show a female erasshopper sunk in the eround and in the act of laying eges. In cases where burrows are made beside a plant stem, the insect commonly seizes the base of the stem with the front two pairs of legs and eradually backs downward as the burrowing progresses. The actual digging is done by the two horny pairs of ovipositors which are dug into the ground closed and then spread out, thus pushing the soil ahead of them. ‘The posterior end of the body is able to rotate through 180° and so pressure can be brought to bear in all direc- tions in the burrow, a cylin- drical burrow being the re- sult. Text-fig. 2 shows the boring mechanism. The dotted lines mark the posi- tion of the ovipositors when pushed closed into the soil, while the rest of the figure shows the ovipositors fully extended to thrust the parti- cles of soil outward and up- ward. Text-fig. 3 shows the manner in which the egg is pushed out between the ovipositors. TEXT-FIG. 3. Posterior end of female Jola Grasshopper showing exit of egg. A, first stage, in which egg lies be- tween upper and lower pairs of ovi- positors. 5, second stage, in which egg is grasped between upper pair of ovipositors. The whole process of burrowing and egg-laying has been studied carefully in the laboratory. “The method 10 THE JOLA OR DECCAN GRASSHOPPER used in studying these processes has already been describ- ed for the Rice Grasshopper and is as follows :—An outer layer of soil, from one quarter to one-half inch in thickness, in a glass jar, is divided off from the rest by means of stout cardboard. The top of the soil is covered with the exception of this external layer. The grasshopper is thus compelled to burrow close to the glass. The pro- cess has already been de- scribed in considerable detail by me for the Rice Grass- hopper and it is sufficient to say here that oviposition in the case of the Jola Grass- hopper is almost exactly sunilar. The accompanying Text-fig. 4 gives an ac- curate picture of the grass- hopper in the act of egg-lay- ing. An egg has just appear- ed between the two pairs of Ovipositors and the upper pair is moving down to seize the egg prior to depositing it. The great extension of the abdomen is worthy of notice, individual abdominal segments being extended to TEXT-FIG. 4. fully twice their original Female Jola Grasshopper laying eggs. length. The time required for the digging of a hole and the deposition of an egg-mass is very considerable. In one case observed in the field, for the whole process in black cot- ton soil a period of one and a-half hours was taken from the beginning of digging to the completion of egg-laying and the emergence of the female from the ground again. The following periods were observed in rather light soil in the laboratory : P.M. Digging commenced ake ... 4.40 Egg-laying commenced Skis Sea OVE Do completed 5s eet One) Completion of deposition of froth on top of egg mass fs 2. EGO Grasshopper emerged from hole see | Ove Yo nul ae ’ spent deri old Jo. dgareA—.& .oril susbeni huoose odd to lgnayA—. & or'l neta built add to qr i—.2 we ani tidvrot orld to pass ” yi! EXPLANATION OF PLATE TT. Fic. 1.—Part of an egg-mass of the Jola Grasshopper in a lump of black cotton soil. Hic. 2.—Nymph of the first instar. Hig. 3.—Nymph of the second instar. Fic. 4.—Nymph of the third instar. Fic. 5.. Nymph of the fourth instav. Fic. 6.—Nymph of the fifth instar. Fie. 7.—Adult male grasshopper. Fic. 8.—-Adult female grasshopper. The hair-lines beneath the figures indicate the real lengths of the insects painted, the figures being somewhat enlarged. Plate LI. THE EGG-MASS aly We get here then the following figures :— Minutes. Digging te Oe Egg-laying and deposition of froth Ree) Sa Total a7) £10) minutes or one hour and fifty minutes. Observations made in the field would indicate that this probably does not exceed the average length of time required there, the time recorded above for the case observ- ed in black cotton soil being rather below the average. The eggs are laid somewhat irregularly, there being little of that comparatively orderly arrangement noted in the masses of the Rice Grasshopper. The masses them- selves are rather easily broken and the eggs are not at all firmly cemented together. However, the hole in the black cotton soil is a very solid one and under normal conditions there is little ee of the egg-masses coming to any harm. Plate II, Fig. 1 shows part of an egg-mass exposed in black cotton soil; above can be seen remains of the frothy or spongy mass which is deposited in the hole above the eggs. At times this spongy mass attains a length up to an inch, in some cases being longer than the egg-mass itself. Plate Vii ie..3 shows such a frothy plug in position above an egg-mass. Plate VII, Fig. 2 shows an intact egg-mass, from which the frothy covering has been removed on one side to reveal the eges in their natural position. The egg-masses vary considerably in size and in the number of eggs contained in them. They are much narrower than those of the Rice Grasshopper while at the same time they tend to be somewhat longer. Measure- ments of twenty-one masses gave dimensions varying from 23 mm. X 5°5 mm. to 13mm. X 6mm. Others have been found as short as 9 mm. and counts of eggs made on 21 masses gave the following results:—72, 61, 56, 00, Ol, 49, 47, 43, 49 41, 36, 36, 35, 35,32, 30, 2, 2 23, 21, 9, 8. The average is 38 ego's per mass. Records indicate that a female Jola Grasshopper lays on an average two ege- masses so that we have about 75 eges as the ‘approximate number laid per female. Consistent with the position occupied by the female in egg-laying, the ege-masses are a THE JOLA OR DECCAN GRASSHOPPER placed approxunately vertically and at a depth of one to two inches from the surface. In the field, this depth may be considerably increased where the grasshoppers sink themselves deep into cracks in the process of egg- laying. In this case a depth of three inches or more may be reached. Eege-laying seems to take place in the field always late in the afternoon or inthe evening. Most of the cases observed were noted just about sunset and more than once the coming on of darkness prevented the com- pletion of observations. The earliest case of oviposition observed in the field was one on a demarcation mound about three o’clock in the afternoon. A search was also made in the early morning for ovipositing females but in no case were any found. In the insectary, where the in- sects were not exposed to direct sunlight, oviposition has been observed at almost all times of the day though here again more commonly in the afternoon. Development of the Jola Grasshopper.—As_ already stated, the eges remain in the ground throughout the win- ter months and hatch only after the early monsoon rains have fallen. In 1910, the egg-masses in field cages in the laboratory compound, Bangalore hatched on the 22nd, 25th and 27th of July. Tn the field at Honnali, the hatching was first Aigeruad on the 29th of July. In 1910, the monsoon was late in beginning and it is probable that, in more normal years, the emergence may be somewhat earlier. Here, as in the case of most grasshoppers, the shell splits open at the upper or head end and the insect extri- cates itself still covered by a thin membrane or amnion which is usually carried to the surface and shed there. This is by no means universal, however, as Plate VII, Fig. 5 shows. In this case the amnia have been left inside the shells, the young hoppers emerging as free insects from the ege. The two holes in the amnion, out of which the anterior pair of legs have been extricated, are visible in one of the figures. Plate VII, Fig. 4 shows a hopper in the act of hatching. The young hopper is, at first, pale but, within an hour or so, takes on the permanent dark colour to be described. DEVELOPMENT OF THE HOPPERS 13 FIRST INSTAR. (PLATE II, FIG. 2.) Length of nymph on day of hatching Be) 515615. mim. Length of antennze sees “i Number of segments to acne 528 The structure of the antenne (see Plate VIII, Fig. 8) is worthy of note. Segments 3-7 are subequal in Jength and triangular in section. Segment 2 is short, cylindrical. Segment 1 is almost triangular in outline. Segment 8 is very long, almost as long as the five preceding segments together. The ground colour is greyish mottled with brown. A pale yellow band extends from the base of the antenna, beneath the eye across the cheek, along the ventral margin of the pronotum over meso- and meta- pleure on tothe femur of the hind leg. A distinetly paler band runs along the dorsum from the anterior to the posterior end of the insect. The general shape is much as in the adult insect. There is, however, yet no sign of elytra and the thorax is not at all enlarged. SECOND INSTAR. (PLATE II, FIG. 3.) Length of body a) Ju. t= fo mm. Length of antennae w. 2— WIT Number of segments to FANS ... 9—10 The new segments have been divided off from the base of the terminal club (see Plate VIII, Fig. 9). The divisions are usually still incomplete and may be absent entirely, in which case the antennz have the same number of segments as in the first instar. The general colour is somewhat paler than in the first instar, especially along the sides of the thorax and abdomen, so that the dorsal band is much less distinctly marked off. The depth of colour varies, however, so that it cannot be used as a distinguishing character. The chief distinguishing features are (a) increase in size of shaft of antenne relative to terminal club, (b) the beginning of division in club, (c) the srowth of the external sexual organs (vide infra). THIRD INSTAR. (PLATE I, FIG. 4.) Length of body Be, ... 12—14 mm. Length of antennee Bee 4— 4°5 ,, Number of segments to paroamen ... 1O—12 The two basal divisions in the club have usually become distinct, while divisions have appeared in segments 6 and 7 and a further divi- sion may at times be noted in segment 3. The terminal club, which in the first instar is about the same length as the five preceding segments combined, is now not much more than half their combined length. The colour 1S) Ut many specimens, the same as that sinseae . 1 One iach =25 millimetres (mm. Ms 14 THE JOLA OR DECCAN GRASSHOPPER described for the second instar. In some cases, however, and this seems to be very common in the field, the nymphs in this instar assume a distinctly greenish colour (see Plate I, Fig. 3) with a markedly reddish tint on the sides of the head, along the external surface of the posterior femur and at the end of the abdomen. In this instar are to be made out the first indications of the devel- opment of elytra. In many cases there is a distinct downward and backward growth of the lower portion of the mesothoracic lobes while in other cases this growth is very indistinct. Scarely asign of devel- opment of a wing bud on the metathoracic lobe can, as yet, be made out (see Plate VIII, Fig. 3). FOURTH INSTAR. (PLATE II, FIG. 5.) Length of body on day of moult ... 16—-18 mm. Length of antennse os 2 O— tj, Number of segments to soon ... 13—15 The colour variations are those noted for the third instar, the green variation, however, becoming more prominent. In this instar, we have a splitting up of the insect into two groups as regards wing development. In some of the nymphs the lower borders of both meso- and metathoracic lobes become turned up. The turned-up portion of the mesothoracic lobe projects about half way back on the metathorax, while the metathoracic lobe laps over it so as partially to cover it (see Plate VITI, Fig. 5). It projects but slightly be- hind the posterior border of the metathorax. In other nymphs of this stage, the wing buds are in much the same condition as that described for the previous instar. The metathoracic lobe is, however, more dis- tinctly developed and may show a slight projection at its pasterer border (see Plate VIII, Fig. 4). In my description of the Rice Grasshopper, I have recorded the occurrence of a similar phenomenon for that species except that it occurs there in the fifth and not in the fourth instar. In the case of the Rice Grasshopper, it was found that this difference was connected with differences in sex, practically all the males showing the advanced developmental stage. An examination of nymphs of the Deccan Grass- hopper in the fourth instar does not, however, show this correspond- ence, as will be seen from the following rearing notes. In a rearing jar (No. 10), there were present, on the 10th September 1910, thirteen nymphs all in the fourth instar. Of these, eleven were males. The division as regards development of wing buds was as follows :— A. Upturned wing buds, 7—all males. B. Downturned wing buds, 6—4 males and 2 females. A record from another jar (No. 8) taken on the 16th September showed, out of twelve nymphs (nine females and three males), only one with upturned wing buds and that a male. From these, as well as from other breeding observations, it appears that about half the males undergo the more rapid development while other records indicate that the females split up in much the same way as the males. DEVELOPMENT OF HOPPERS 15 FIFTH INSTAR. (PLATE II, FIG. 6.) Length of body Os ...22 —25°5 mm. Length of antennze eh o—10 ve Remaber of segments in itenaes . 1d —17 Colour variations as in previous instar. Those nymphs which in the previous instar showed the more ad- vanced development now show the elytral bud grown backward almost or quite to the posterior border of the metathorax (see Plate II, Fig. 6 and Plate VIII, Fig. 6). The metathoracic bud shows no appreciable change. Those nymphs which showed the more belated development now correspond in wing bud development to the more adyanced group of the previous instar, For those nymphs showing advanced development this is the last nymphal instar. With the following moult they assume the adult form. SIXTH INSTAR. Length of body... shee ... 264—29 mm. Length of antennz awe 95-—11 _,, Number of segments to antennas 2 he le Little need be added to the description for the fifth instar as the nymphs in the sixth instar only reproduce in general the structure noted for the more advanced forms in the previous instar, the only difference being the greater size. From the above description, it will be seen that the Jola Grasshopper passes normally through either five or six instars. Apparently about half the grasshoppers undergo the more rapid development. Specimens collected in the field show very great variation in size. The measurements published by Boli- var and myself were taken from comparatively large specimens. Males have since been collected in the field varying from 23 mm. to 40 mm. in length while females have been found varying from 25 mm. to 40mm. The females are much stouter than the males and on the average decidedly longer. Reared specimens have not attained the extreme size of those captured, the males varying from 26 mm. to 34 mm. and the females from 30 mm. to 34 mm. It is very probable that the conditions in confinement were not favourable for growth. The small specimens taken in the field were found in one or two localities only, and it appears likely that here also the food supply was insufficient or other conditions were not so 16 THE JOLA OR DECCAN GRASSHOPPER favourable. In any case, where such a marked variation in size exists, it is clear that the measurements given above for the various nymphal instars are only approxi- mate and cannot be used in distinguishing one instar from another. [For this purpose, the structure of the antenne, the development of wing buds, changes in colour and the development of the posterior end of the abdomen will furnish the necessary information, and with a little practice one is able to identify the instar of a particular nymph with a fair degree of accuracy. The table on page 17 gives the results of three separate rearings, and these records may be taken as typical. From this we get the following periods for the various instars :— Rearing A :—1st instar oer ... 138—19 days inden 5. aa te 4 ee ata eee Wag ee 3 es Wy Pee Ath ,, me me Sth ,, ee so LIZ 19- 6th .? 18-26 <5, Total length of dev plopment for individuals with 5 instars Fe ... 86—87_,, Total length of development for individuals with 6 instars a 2.6 MOO = LD ieee Rearing B :—1st instar - Bend (eet sae Onduee,, arts a8) A= Srduae: ae os. 14--18';, Ath ~,, oe see to Orees, Sthy=",, wwe ... 14—19 ,, Gth ,, soe AB 199 Total length of development fot individuals with 5 instars ... 81—84 ,, Total length of development for individuals with 6 instars bis ... 85—89 ,, Rearing C :—1st instar ne Ae all peaeiae oe Qnd ,,; iP oP ee 1 Stan ae oh .. 12-14 ,, Ath -~*;, he sat LB LTA tliat, ie .. 13—14 ,, Gihe-,; 17—24 ,, Total length of development oe fagculie | with 5 instars 68 & Total length of development for indiv iduala with 6 instars mes 79—88 _,, The nymphal instars are thus approximately two to two and a-half weeks in length. The sixth instar is some- what longer than the rest or from two and a-half to three RECORD OF REARINGS ype OTRULAYT z qnpe Ter | zOI IL ¥ 10L OL 28 | 1?40.L mm. Seal Se! tat ft “ON SoTRUL TD 0 €f (OE TO Me (OE WL ke qnpe oTPIN z sqyupe OT RUA 7 10L IL 96 zOL IL & IC {SIE We yee IL «6 | | FTNOTA 439 WOW WIG qNOW UIE qjape | | Rete 7 |r) Ol Obeo.) 7 Tt -R0n6 IGT 10 OL 91 | Or On | be One: 2 OL OL ZI 1s ROL Ome fe | Oe, Be OL OL OL i SOL 16 Gi E ORGr Fi So[PUloy | | | WUpV 1 eal oie Th th i Ge oe at 101 OL O& | Ty 07, ORs ys stnOlvaued OL OF 61 (jeje a2 | WOR Ge. Wo | OL OF 9T | [ie Wahe ye fa Z hOe Gt | 4 SoleUl | Fara fear 6 T | 016 4% YUPV 1 | jpodvosea OM, \L |0OL6 Guince ie | ic Or On rn tT |0L6 wz OL if T Ge | oe oye ie | |i Ore Te 10 OF Ié | E Oren 2) | Tt | 016 0 OL OL 0¢ |@ | OL OL 9 | |< | 016 61 OL OL 1% % (01 or % @ |OL6 at OL OL OT I |Or 6 68] L Or 6: 41 ayeq. | [eqoy, “ont| Sura | \teqog, ON | 99eq | NOW pre PSE We | | 1 |ObGeé 9% | a On Bese T | O16 @ | |OL8 @/9 | OL8 6 Pele WO 6 OL orders |I |Or6 8 Wo parp T (2 106 9 | Sia Orel te aeOneeetn TI |ore6 ¢ T |O18 | |OL8 OF | pe | 6 | [paoosaug| 6 | | Ors 9a! 6 | 016 8 T |0L8 7 | i a 7 |0L8 &| eae € |016 F T |0r8 0@) | uo perp T I |0Lr6 & 6 | OLS 61|OL/oTs 9 TROL |ON| e9eq |TeI0g,|‘on') eq Jon! aed JNOP pug JNOP IST peyoye yy ‘UHddOHSSVEO VIOL JO SONTYVEY AO WIEVi 18 THE JOLA OR DECCAN GRASSHOPPER and a-half weeks. The total length of development is about two and a-half to three and a-half months. This agrees with our records from the field where emergence took place during late July and August and where adult grass- hoppers were found in the latter part of October and in November. In a few exceptional cases, nymphs of the last instar were found in the field as late as the middle of December. A general description of the adult insect has already been given, but a few poimts remain to be mentioned. While the posterior wing bud is quite distinct in the last two or three nymphal stages, we find that, in the adult, practically all trace of it disappears. Associated with the loss of the powers of flight, is a weak development of the organs of locomotion generally. The legs are short and slender and the shortness and slightness of the hind femora as compared with the abdomen are very marked. An examination of the musculature shows a very feeble development compared with that in a fairly normal form, such as the Rice Grasshopper. Associated with the abor- tion of the wings, is the absence of more than mere traces of the wing musculature. ‘This weakness in powers of movement is, however, not at all associated with a weak- ness in constitutional powers, the Jola Grasshopper being in this respect decidedly robust. Another feature worthy of note is the presence of a olandular structure, whose duct opens in the medio-dorsal line on the articular membrane between the first and the second abdominal segments. The gland itself is ue in Plate X, Figs. 3 and 4; its opening in Plate X, Fig. As indicated, it is a paired structure closely applied is the dorsal body wall in the region of the first abdominal seenient. The secretion is a slightly yellowish fluid some- what milky in appearance with a peculiar odor and having a distinctly alkaline reaction. It appears to be repugna- torial in nature. The secretion is capable of being ejected with considerable force, being squirted at times to a dis- tance of one or two inches. Similar glands have been found in some other members of the sub- family Pyrgomor- phine, e.g., a Pecilocerus pictus, Fabr., and Attractomor- pha crenulata, Faby. In the above description, an account of the develop- ment of the posterior end of the body has not been DISTRIBUTION OF THE GRASSHOPPER 19 included. This development is illustrated in Plate IX, the development in the male being shown on the right side and that of the female on the left. The develop- ment corresponds quite closely with that already described for the Rice Grasshopper, so there is no occasion to go into details here. As indicated (Plate IX, Figs. 1-6), the ovipos- itors develop as paired outgrowths on the lower or ventral side from the posterior border of the eighth and the ninth abdominal segment respectively. These processes gradu- ally grow backward and ¢ gain in stoutness until, in the adult stage, they form two powerful pairs of diggers, Here, as in the case of the Rice Grasshopper, we find the separation of two lobes from the inner faces of the two upper processes (see Plate IX, Fig. 3) to form a forked structure (furcula supravulvalis) which comes to lie just above the genital opening. In the male, a single process grows back gradually to form the scoop- -shaped Se “(subgenital lamina) in which the penis comes to lie (see Plate IX, Figs. 7-12). DISTRIBUTION OF THE JOLA GRASSHOPPER. The Jola Grasshopper has by far its most extensive distribution in the Bombay Presidency, where it is to be found in almost all the Deccan Districts including a small part of Khandesh. It has not yet appeared in Sholapur District. In addition, it is to be found in almost all the taluks of the Karnatic Districts, Belgaum, Bijapur and Dharwar. In Madras Presidency, it has appeared only in Bellary District, in Adoni, Alur, Kudligi, Hadagalli and Harpanhalli Taluks.* In Mysore it is, at present, restricted to the northern parts of Chitaldrug and Shimoga Districts near the point where Mysore State and Bombay and Madras Presidencies meet. The taluks affected are :—Honnali and Channagiri in Shimoga District ; Davangere, Jagalur and Chitaldrug in Chitaldr ug District. In all probability it extends, at least to some “extent, into Hyderabad as it has been found in districts bordering on that State. Enquiries made by me have, however, elicited the fact that 1The information with regard to the distribution of the grasshopper in Bombay Presidency was kindly furnished by) Miry Ga Et. eae, Director of Agriculture, Mr. T. F. Main, Deputy Director of Agriculture, and Mr. M. L. Kulkarni, Divisional Inspector of Agriculture. The information for Madras Piesldntiog was furnished by Mr. Y. Ramachandra Rao, Assistant Entomologist, through Dr. Barber. C2 20 THE JOLA OR DECCAN GRASSHOPPER it has not been reported to the Hyderabad authorities as yet. The approximate area over which the Jola Grasshop- per is known to occur is indicated on the accompanying map (Text-fig. 5). Considering its present distribution, if is practically certain that this pest has orrginated in Bombay Presidency and has spread from there into Madras and Mys sore. Just when and where it made its first appearance as a pest is CENTRAL PROVINCES TEXT-FIG. 9. Map of South India to show approximately the area infested by the Jola or Deccan Grasshopper. unknown. Mr. T. F. Main, Deputy Director of Aga ture, Bombay Presidency, is of the opinion that it has bee1 present there for many years, though it has excited shied tion only within the last four or five years. It has been present in Mysore as a pest for only about four or five years and the same appears to be the case in the Madras Presi- dency. It is clearly a form indigenous to the Deccan and DISTRIBUTION IN MYSORE P11 probably was originally a harmless feeder on grass. Grasshoppers belonging to the section Orthacres are by no means common forms in India and, where found, appear usually to occur in small numbers. This is the first one of the family that has appeared as a pest. -We have here, in all probability, an interesting example of a harmless insect becoming a serious pest by modifying its feeding habits. With the more abundant and nutritious food provided by the cultivated cereals, it has increased very rapidly in numbers, so that it may now be looked upon as one of the most serious grasshopper pests in India. JAGALUA TK. a3 IhapKansinies (Sy Map of portions of Shimoga and Chitaldrug Districts to show areas infested by the Jola Grasshopper. It must not be supposed that this pest is to be found evenly distributed over the districts and taluks enumerated above. In fact, the distribution appears to be decidedly localized. ‘The accompanying map (‘Text-fig. 6) shows in creater detail the distribution in Mysore. As indicated, there are five infested areas quite distinct and separate from each other. As will be noticed, all of these, with the exception of the area in Channagin Taluk, are situated on 99 THE JOLA OR DECCAN GRASSHOPPER main roads where the trafficis heavy. A similar localized distribution occurs in Bellary District and the same is the case with regard to those portions of Dharwar District bordering on Mysore. The reason for this localization is not clear but a possible explanation is given below. The fact that this pest has been doing damage for only a comparatively short time prevents us from expect- ing that this localization will persist. In fact, we may, with a fair degree of certainty, predict that the insect will spread from these various centres, so that in compara- tively few years it will cover those taluks already infested and will gradually spread out from them to the neighbour- ing ones, so that the whole of the northern part of the State where dry land cereals are extensively grown is in danger of infestation within a comparatively short time. CAUSES FOR UNEQUAL DISTRIBUTION OF THE GRASSHOPPERS. An examination of the map marking the distribution of the Jola Grasshopper in Mysore reveals, as already stated, the fact that this pest is not present over one continuous area but that it is to be found in more or less isolated tracts varying from one to several thousand acres. These tracts are, at times, considerable distances apart, so the question at once arises how the pest has spread from one to the other. That the pest has been present feeding on wild plants in all the localities now infested and that in all these centres it has gone over from wild plants to feed on cultivated crops, is highly improbable. The fact that the infested areas have been enlarging from year to year, in itself, indicates that this grasshopper, although wingless, has considerable powers of spreading. However, such a gradual spread can- not account for its appearance in distinctly separated tracts. The fact has, however, been observed in connection with the extensive cart traflic which takes place between places in Dharwar District and those in Shimoga or Chitaldrug District, that jola is usually cut and taken along as fodder in the carts." It might very well happen, then, that a cart eoing from an infested tract would take along with the 1This fact was first brought to my attention, by B. C. Shantappa, Fieldman in my - office. CONDITIONS AFFECTING SPREAD 23 jola a certain number of the grasshoppers, for these insects are sluggish in the extreme and might, in all probability, be carried many miles in a cart without becoming in the least disturbed. This probably happens comparatively rarely, other- wise the spread of the pest would have been much more rapid and general than it has been. It may frequently happen that the number so transported is too small for the grasshoppers to make a start im the new territory, for they might all be destroyed by various natural enemies or die from other causes before they reach matu- rity and are able to lay eggs. In any case, this possible means of spread is a matter of considerable importance, and the knowledge of its possibility should be widely spread, so that precautions may be taken to guard against it as far as possible in the future. With regard to the gradual spread within the terri- tories already infested, some important observations have been made. It has already been noted that, up to the present, crops grown on black cotton soil have suffered most; at least that is the case in Mysore.