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Psyche 13:123-134, 1906.

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19061 MORSE-NEW ACRZDZIDAE FROM THE SOUTHERN STATES 119 NEW ACRIDIIDAE FROM THE SOUTHERN STATES. BY ALBERT P. MORSE, WELLESLEY, MASS.
SEVERAL previously unnoted members of this family were taken in the summer of 1905 during a second trip in the South under the auspices of the Carnegie Insti- tution of Washington.
Nomotettix cristatus denticulatus var. nov. This variety, for it is unlikely to be more than that, is more scabrous than the type form, with the margins of the pronotum very minutely serrulate, sideg of the vertex of the headless regularly convex, its carina less protuberant, the carina of the pronotum thinner and higher, the middle femora with undulate margins, and the upper edges of the hind femora usually with inwardly or upwardly directed den- ticulate processes.
Six males, one female; Caddo, Haileyville, So. McAlester, I. T.; Denison, Tex. Aug. 6 to 13.
Hippiscus immaculatus sp. nov.
The specimen under consideration is the size of H. rugosus. The pronotum is less rugose, smoother in outline and in surface, a little narrower; the hind margin slightly obtuse-angulate, its sides straight and its apex rounded. Wings like those of rugom, the tip infuscated but not maculate. Ground-color of tegmina a pale, almost vinaceous, brown; the basal half of the anal field suffused with fuscous except along the anal vein; the distal half of the costal field more or less suffused and the basal third finely maculate, the proximal part of the discoidal field evenly suffused, the veins and venules of the distal part more or less infuscated apically, and a slight fuscous suffusion near the base.
Compared with mgosus the specimen differs relatively little structurally or in wing-marking, but radically in the tegminal pattern which suggests that of tuber- culatus but is much less distinct.
One male, Clarendon, Tex., Aug. 18.




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PSYCHE
[October
Podisma scudderi sp. nov.
Head large, eyes large and prominent, vertex very blunt, but little protuberant,- in form and proportions recalling Dendrotettix. Pronotum robust, depressed rather than compressed, especially at the shoulders, carina distinct on metazone, evanescent on prozone, posterior margin slightly convex, sub-emarginate, sutures deeply im- pressed.
Prosternal spine short, acutely pointed, conical with excavate sides. Tegmina ovate-lanceolate, separated by their own width, anterior margin strongly convex, posterior slightly so, apex evenly rounded. Carina of abdomen indistinct. Valves of ovipositor stout, outer margins finely dentate and strongly sinuate, con- trasting markedly in robustness with the same organs in P. glacialis variegata, from which the presence of tegmina distinguishes it a$ a glance. Color luteous beneath; above mixed olive green, fuscous, and brown, with more or less cherry red on inner and outer faces of hind femora. Feet greenish, tibiae varied, strongly pubescent, with black spines. Length: 25; hind femora: 12; pro- notum: 5; tegmina: 4 X 2.5 mm.
One female, Cheaha Mt., Ala., July 13, 2300 feet. This is a stout-bodied species, resembling Dendrotettix in the form of the head and proportions of the eyes, and the discovery of the male will be awaited with interest. The single example secured was taken while sweeping grass and shrub- bery in the vicinity of Pulpit Rock, near the extreme summit of the mountain. Pro- tracted search for a male or additional examples was unavailing. I take great pleasure in naming this notable species in honor of Mr. Scudder, whose scholarly researches in orthopterology form the foundation on which all later study of the North American representatives of the order must be based; whose interest, example, and friendship have been a never-failing inspiration. Melanoplus latens sp. nov.
Subgenital plate of male from above rounded apically, in side view short, its lat- eral and ventral outlines nearly equal, a little elevated apically. Furcula obsolete
or represented by two small, rounded protuberances. Last dorsal segment a little emarginate.
Cerci long, a little surpassing the supra-anal plate, two-and-a-half times or more as long as their basal breadth, nearly four times as long as their middle breadth, tapering rapidly on basal fourth; bent slightly upward at this point, sub- equal or slightly expanded sub-apically, tapering to a rounded, flattened apex. Valves of ovipositor of female short, rather blunt and usually dull pointed.



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A short-winged, red-legged species having much the habitus of M. scudderi and occurring with it in thickets and woodlands. Tegmina acutely pointed, equalling head and pronotum. Vertex of head rather protuberant. Mid-carina of pronotum
distinct, equally developed throughout. Prozona slightly inflated. Hind tibiae cherry-red.
Length: &19-22; 9 ,27-30.
Hind fern. : $,12-13; 9 , 14.5-16.
Tegmina:
8, 6.5-7; 9, 7-8.5mm.
Caddo, I. T., Aug. 9. Six males, seven females. To this species I refer also three females from Howe, I. T., Bonita, Tex., and Magazine Mt., Ark. Melanoplus tepidus sp. nov.
This species most closely approximates M. obovatipennis, agreeing with it in size and general coloration, but may be distinguished from it by the following characters: - Sub-genital plate of the male feebly but distinctly tuberculate sub-apically; the upper valves of the ovipositor of the female narrower at base in side view; the pro- notum is more elongate and slightly inflated, its sides and top slightly convex instead of straight, its lateral lobes less deep, and the longitudinal fuscous stripe thereon broader anteriorly, of nearly equal width throughout, covering one-half or more of their depth; the tegmina are slightly more elongate, the eyes of the male are large and very prominent, and the vertex of the head narrower, more prominent, and rather deeply sulcate.
Three males, three females; Meridian, Miss., July 16. Melanoplus tribuloides sp. nov.
Similar to M. tribulus but with the digits of the furcula much wider and longer, flattened, from enlarged bases, in length equalling or exceeding the middle breadth of the cerci; the cerci narrower in the middle. Two males, three females; Cheaha Mt., Ala. 2000-2400 feet.
One male, two females; Turnipseed's Ranch, 1000 feet, near base of Cheaha Mt. Melanoplus tuberculatus sp. nov.
A rather small, inconspicuous species, long-winged, flavescent brown in color, with unspotted tegmina, faintly barred hind femora, and very pale yellowish green hind tibiae. Fuscous stripe of the lateral lobes of the pronotum restricted to the



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prozona, brownish, sometimes obsolete. Sub-genital plate of the male seen from above smoothly rounded posteriorly, its ventral outline from the side smoothly convex, terminating posteriorly in an upwardly directed, acute, sub-apical tubercle, the lateral margins ampliate at base. Last dorsal segment of abdomen of male emarginate at origin of furcula, the latter consisting of a pair of short, triangular, flattened proc- esses from expanded bases on the segment, scarcely as long as the segment, parallel, and widely separated.
Cerci short, but little longer than their basal width, wide and very stout at base, tapering rapidly, the apical half sub-equal, tapering to a rounded apex, bent strongly upward and inward, the apex flattened and a little reflexed. Tegmina a little surpassing (8) or about reaching (Q ) the hind knees. Body: 3, 18-22; Q, 19-27. Tegmina: 6\ 14-18; Q , 16-19. Hind fern.: 8, 11-12; Q , 13-15 mm.
Eleven males, three females; Quanah, Texas, Aug. 21. One male; Wichita Falls, Texas, Aug. 15. Melanoplus scudderi latus var. nov.
Two males from Bonita, Texas, which I refer to this species with some doubt, possess exceptionally broad cerci, the depth nearly or quite equalling the length, the lower margin very strongly convex. To this form I apply provisionally the varietal nanie latus.




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THE SWARMING OF CULEX PIPIENS.
BY FREDERICK KNAB, WASHINGTON, D. C.
IT has been the writer's good fortune to observe the swarming and mating of Culex pipiens upon four consecutive evenings, October 15-18, 1904. Many notices,
of the swarming of Culicidae and related forms have appeared, but most oFthe - accounts deal with the swarming simply as a remarkable phenomenon while its sig- nificance escaped them. It therefore seems worth while to record my own observa- tions. Following these I shall give the more interesting data of previous writers,. and at the end, a bibliography of the subject. My observations were made at Urbana, Illinois, under exceptionally favorable conditions. Although the country about Urbana is well drained and there is but little water, mosquitoes were remarkably abundant. As far as could be determined all came from one source. On the outskirts of the town is a small stream, known as the Salt Fork, which, during dry weather, becomes practically stagnant. About a mile up the stream the water was polluted by the discharge from an abattoir. The foulness of the water was such that the fish normally present in the stream were all destroyed and thus an ideal breeding-place for mosquitoes was created. Early in October the writer found the larvae of Culex pipiens present in immense numbers,. and when the shrubbery bordering the stream was disturbed the imagos rose in great clouds. These mosquitoes, however, showed no inclination to leave the water- side and would quickly return to the shelter of the marginal vegetation. October 15 was a warm autumn day and its close was marked by one of those clear calm evenings when not a leaf stirs and the air appears to be perfectly still. At five o'clock the writer was crossing a corn-field not far from the stream. The sun was already near the horizon and its direct rays were cut off by an intervening line of tall trees. When near the middle of the field a cloud of mosquitoes was noticed directly overhead. The lowest mosquitoes were about the writer's head and shoulders, the topmost ones perhaps five feet higher; the transverse diameter of the swarm was about two feet. The high-keyed piping, vibrating between two notes in constant rapid reiteration, was very distinct. The variations in tone seemed to correspond to the upward and downward movements of the individuals. In the light of the succeeding observations it would seem that this swarm had been forming above the writer's head from the time he entered the field. The swarm was watched for about twenty minutes. The individuals in the swarm flew up and down amongst



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each other with a kind of weaving motion - a downward and forward plunge and back again, performed without unison or regularity.. The movements were suffi- ciently slow to allow the plumed antennae of the males to be clearly distinguished and it appeared that the, swarm was composed wholly of males. Once a female was seen to dash into the midst of the swarm and emerge on the other side united with a male.
The insect-net was swept through the swarm a number of times. At each stroke the mosquitoes would disperse somewhat but returned at once to their former position and continued their dance, and there was no perceptible diminution of their numbers. An examination of the captures showed 897 males and four females. This count includes the female observed passing through the swarm, as narrated above, and it is obvious that the other three females in the capture are not to be con- sidered as members of the swarm. They may have entered the swarm unnoticed in the manner described, or they may even have been hovering about outside of it. The observations of T. H. Taylor (in Miall & Hammond, The Harlequin Fly) show a like condition in Chironomus. On a still evening his captures from a swarm were 700 males, no females. On a windy evening, when the swarm was thrown more or less into disorder by the breeze, a capture of 4300 specimens included 22 females. Upon turning to leave the mosquito-swarm another one was discovered close by, hovering over and about a corn-stook. The swarm extended about half way down the side of the stook and kept on the south side of it, the mosquitoes all facing north- ward. Although there was no perceptible breeze it was thought that the attitude of the mosquitoes was in response to a current of air and subsequent observations confirmed this supposition. It was but seldom that one of the mosquitoes alighted on the corn, and as in the cloud first observed, all appeared to be males. A round of the field showed that each corn-stook had its swarm of mosquitoes, and further- more, single stalks that remained standing had small swarms dancing over them - sometimes of only six or eight individuals - and the bushes and small trees on the edge of the field had their swarms. In every case the mosquitoes faced northward and the swarm kept on the south side of the object of attraction. Always the mos- quitoes gathered over some prominent object such as a tree or a projecting branch, a bush, a corn-stook or a person. In this last case the swarm would move with the person and the only way to get rid of it was by passing under some taller object where the swarm would then remain.
On the following evening at five o'clock the field was again visited. Upon ap-
proaching the region of the creek swarms of mosquitoes were noted over every tall object - at the tops of telephone-poles, orchard-trees and shrubbery. On a very tall elm, standing alone in a pasture, a swarm was dancing before a projecting branch



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19061 KNAB-SWARMING: OF CULEX PIPIENS 125 In the corn-field the swarms were found, as on the evening before, over every prominent object and as the writer entered the field a swarm immediately began to form over his head. This time, however, the position of the swarms in relation to the objects was the opposite of the evening before - the mosquitoes were now all facing south- ward and they kept on the north side of the objects. The trees on the south side of the field, some of them 25 or 30 feet high, had immense clouds on their north sides. As on the evening before, there was no perceptible breeze but the drift of smoke showed that there was a current of air from the south. Station was taken near the row of trees bordering the field and some swarms dancing before projecting limbs kept under observation. Repeatedly females were seen to issue from the foliage, dash into the swarm, and emerge united with a male. When in copula the male and female face in opposite directions, their bodies in a horizontal plane; the female dragging the male after her.* The pair (or rather the female) would fly upward for a while and then slowly drift towards the ground. Once a pair in copula was seen to issue from one swarm and plunge into another swarm close by. The pair made great haste to extricate itself while the swarm was immediately thrown into frantic excitement and the mosquitoes danced up and down at a furious pace for some time, until at last the ordinary measure of speed was regained. With the growing darkness the excitement in the swarms increased and the movements became more rapid.
Few successful unions now took place.
Females entering the swarm would
be pounced upon by two or three males, and together, tumbling over each other, they would fall to the ground and there separate. Towards the last no more females appeared and with the increasing darkness the swarms rapidly diminished, the males flying off into the air.
At five o'clock on the following evening the swarms were found as before, dancing over every object projecting above the general level. Single mosquitoes were seen flying rapidly and straight. These looked larger than the dancing males and when captured proved to be females. The air was again very still with a current from the south and, as before, the dancing males faced towards it and kept on the opposite side of the objects. The west side of the field was bounded by tall trees and high up on these, at least fifty feet from tlie ground, before projecting branches, clouds of mosquitoes could be distinguished while lower down on these trees there were none. Station was taken at a corn-stook to determine how long the dance would continue. As the darkness grew the numbers began to diminish, and at 5.50, when the darkness -
*Qoeldi (0s mosquitos no Para, 1905, p. 74, pi. I, fig. 3a) describes and figures the copulation of Stegomyia calopus.
In that species the male clings to the under side of the female.



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126 PSYCHE [October
was almost complete, the last male flew away. The departing males flew upward
and none of them alighted on the stook.
On the fourth evening the field was visited nearly an hour earlier than before. The sun was still shining and there were no mosquitoes present. Later, when the sun had disappeared behind the trees, the swarms were again present just as on the previous evenings. On this evening, however, there was quite a breeze blowing and the mosquitoes could not maintain their position over the projecting objects and swarmed altogether on the leeward side of them. Otherwise their behavior was much the same, only that the freshening wind occasionally threw the swarms into confusion and greater activity. Rain and cold weather followed the next day and put an end to further observations and presumably to the swarming, There are many records of swarms of Culicidae and related forms, although in many cases there is no exact indication of the identity of the insects in question. I am convinced that all such records, in so far as they refer to swarms of the nature described above, apply to Nemocera and probably in every case either to Culicidae or Chironomidae. I believe that these swarms of dancing males, congregated for sexual intercourse, are peculiar to the Nemocera. Many of the records from un- trained observers, called forth by the appearance of these Diptera in extraordinary .
numbers, though incomplete, are nevertheless of interest. In nearly all of them the fact that the swarming leads to sexual union has been entirely overlooked. Moufet, in 1634, already speaks of these swarms and notes how they gather at the gables of houses and over the heads of people passing over bridges. It should be noted that in his chapter "De Culicidum" the Culicidae and Chironomidae are not distinguished, as indeed has been the case with many a writer since, The oldest record of the copulation of Culex appears to be that of the Spaniard Diego Reviglias, communicated to the Leopold-Carolinian Academy in a letter dated 4 March, 1728, but not published until 1737. Reviglias observed under the micro- scope, and described at considerable length, the sexual union and the copulatory apparatus of the mosquito. He treats his discovery as a very important one, which indeed it was in those days of lingering belief in spontaneous generation. However he does not mention swarming and there is reason to believe that he had before him a species which does not swarm - a matter which I shall take up again farther on. Later the French commander Godeheu de Riville also claimed as the first his obser- vation of the copulation of mosquitoes, made on board his ship. The account is quite detailed and it is evident that in this case likewise copulation took place without swarming. I shall treat of this article more at length in another place. Perhaps the earliest definite record of mosquitoes swarming is that by Swinton,



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19061 KNAB-SWARMING OF CULEX PIPIENS 127 published in 1798. Swinton describes some swarms which he, together with a friend, witnessed on August 20, 1766, in a garden at Oxford. The account has been drawn upon by later writers but I quote it here as it brings out very clearly the habit of con- gregating over prominent objects. There can be little doubt that the swarms in .
question were Culices as Swinton especially remarks upon the great annoyance caused that season by the bites of the unusually abundant "gnats." He relates
that "about half an hour before sunset, such an immense number of gnats filled the atmosphere in which we breathe, as I had never seen before. We both of us also then observed six columns, formed intirely of these insects, ascending from the tops of six boughs of an apple-tree, * * * to the height of at least fifty or sixty feet. Two of these columns seemed perfectly erect and perpendicular, three of them oblique, and one approached somewhat towards a pyramidal form." He further relates that other swarms were seen in the vicinity on the same evening. In con- clusion he states: "I have been informed by the Reverend Dr. Wyndham, Warden of Wadham College in this University, that, about thirty years ago, many columns of gnats were perceived to rise from the top of the steeple of the cathedral church at Salisbury, by a considerable number of people. He likewise declared, that these columns were seen both by himself and the Reverend Dr. John Clarke, then Dean of Salisbury; that, at a small distance, they resembled smoke; and that this at first occasioned a sort of alarm, many believing that the church was on fire." There are a number of accounts of such swarms about church steeples causing alarm of fire. We have them from Germar (1813), Boll, Kirby and Spence,. and Hagen.
Boll records three such swarms. One of them on the steeple of the Nicolai church in Hamburg took place on a June evening at nine oclock. The discovery of the true nature of the apparent smoke, after the fire-department had been called to the spot, caused great merriment in the crowd of spectators. In 1807, when the 'St. Mary's church in Neubrandenburg served as a powder magazine, the sudden news that the steeple was on fire caused many of the inhabitants to flee precipitately from the city. As the column of smoke about the steeple did not increase, some courageous men finally ventured onto the tower and discovered that the source of alarm was an immense swarm of gnats. Another swarm was observed about the cross of this same church-steeple, at a height of 300 feet, on the afternoon of August 20, 1859. Hagen relates that dense swarms of gnats about the church-steeple at Fischhausen caused an alarm of fire which has earned for the inhabitants the nick- name of "Miickenpeitscher." Koch has reported a swarm from the wings of a windmill, at a height of perhaps a hundred feet from the ground, curled by the breeze and resembling smoke.




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PSYCHE [October
Holiday states that Culex detritus* occurs at Holywood, County Down, "in mul- titudes, during the day among hedges on the seacoast, in the evening in columns about the tops of trees, appearing like smoke at the distance of a furlong." Weyen- bergh records two swarms of Culex pipiens from the vicinity of Haarlem, observed in 1857, dancing in perpendicular columns. Mott gives an interesting account of an unusual gathering of gnats observed by him in 1879. As the article is not generally accessible and describes well the phenom- enon, I quote it nearly in full. "On the evening of September Ist, between six and seven, after a fine, sunny day, the sky being clear, and the full moon just rising as the sun went down there was a grand festival among the gnats. Above the tops of the trees and hedge-rows in the low meadows north ol Leicester these little Diptera were out in immense numbers. * * They assembled in groups of various shapes, some- times a vertical column from 6 ft. to 20 ft. high, and 1 ft. to 3 ft. diameter, rose from a tree top like a pillar of smoke. Sometimes a sheet 4 ft. or 5 ft. high and 10 ft. long hung above the hedgerow, but seemed never more than a foot or so in thickness. The following evening, at the same hour, the sky being more clouded, a few gnats only were to be seen; but on the evening of the 6th, with the sky again cloudy, there was a still more remarkable display of gnat life. The little creatures were out again in millions, but this time the vertical column formation was adopted by nearly the whole of them. These columns rose from the hedges on either side of the road, and were visible for half a mile a-head at irregular distances, averaging, perhaps, 21 ft- or 15 ft. They formed an avenue of such a singular and unusual appearance that everyone who passed along the road paused at intervals to watch and wonder at them- This piece of road is about half a mile long, on the top of an embankment which carries it over the low meadows and the river. At the farther end there are a num- ber of trees, and from the top of nearly every tree three or four of the strange, smoke- like columns could be seen standing up in the air, always straight but not always vertical, some of them being inclined at small angles. * * * On watching one of the columns closely, it was apparent that all the gnats had their heads one way, facing the breeze, which, however, was a very light one. It was a calm evening; what air- current there was came from the south-east. It seemed to be sufficient occasionally to press back the column a few inches from its normal position, and whenever this happened the whole body of gnats jerked themselves forward again with one per- fectly synchronous impulse."
A picturesque account of a remarkable swarming of Culices, at Lewisham Road *Haliday's Culex detritus greatly resembles the common Culex pipiens and most probably the observation should be credited to the latter species.



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19061 KNAB-SWARMING OF CULEX PIPIENS 129 near London, is given by Douglas.
During ten days he observed "the air thick vith millions of them, at times charging in close column up the road, like a squadron of cavalry, at other times engaged in dancing up and down, after the manner of their race." These swarms were in evidence only during the hour before dark and it appears were over or near the road, v, ithin reach of the riding whips and sticks of the 4 4
profanurn vuZgus." Near by "are several tall trees, and round the top of the high- est one only, at the same hour of the evening that the periodical saltatory performances are going on in the road, enormous swarms of gnats congregate. At first they appear as a small black cloud curling about the ends of the branches, and soon, when the air is calm, rising in a close column, like smoke from a chimney, for a distance of some 20 or 3C) feet, the bulk gradually becoming more grey and attenuated until lost to sight in the upward progress. When a breeze is moving, the insects, always pre- serving close order, are blown out laterally, and after skirmishing with the wind return to their cover among the top leaves of the tree.'' This last remark may be an assumption and at such distance from the ground could hardly have been based upon actual obiemation. Douglas suspeets that the species in the tree was "not the same as that of the acrobats of the road," and with right; unfortunately neither form was definitely identified. It further appears from the remarks of Douglas that these swarms are an annual occurrence, only that the number of individuals varies greatly from year to year.
In all the foregoing notes the writers failed to notice the true fhnction of these gatherings of Nemocera. However it had not escaped that keen observer Gilbert White. He was evidently uncertain of the identity of the insects concerned, for in his posthumously published notes he calls them ''empede8 or tipulae." Speaking of their swarms at evening he says: "At this juncture they sport and copulate; as it grows more dark they retire. All day they hide in the hedges. As they rise in a
cloud they appear like smoke."
No further mention of cdpulation in connection with swarming appears until Taschenberg's popular account of Cukx pipiens, pub- lished in 1882. He notes their habit of gathering at the gables of houses and other prominences and describes how the females fly to the swarm of males to effect copu- lation. In the notes on the swarming of Chironomidae which follow, Taschenberg describes the formation over trees and in tall columns, and we are left to infer that the Culex swarms do not assume the columnar form - at least not in the same degree- Theobald's brief, disjointed notes on the pairing and swarming of mosquitoes would hardly convey the correct impression to the lay mind. He corroborates Tasch- enberg's statement that in CuZex pipiem the females fly to the males to copulate but he failed to note that the males congregate about prominent objects. The brief



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130 PSYCHE [October
remarks on the swarming of CuZex cantans, observed twice by Theobald in the fens, shows a distinct mode of swarming in this species. These swarms, composed of both sexes, formed dense clouds which quite darkened the air. "These insect-clouds were constantly moving up and down about ten to twelve feet above the ground. At times the noise .they produced could be heard a quarter of a mile off, then it would suddenly cease for some time and commence again." It is to be supposed that Mr. Theobald is not to be taken literally when he says the insect clouds were constantly moving up and down but that the motion applies to the individuals in the swarms, as in the foregoing observations.
Radl has written two most interesting and suggestive papers on the light-reac- tions of Arthropods and a great part of his discussion is based on the behavior of swarming insects, particularly of Culicids and Chironomids. It would lead too far to enter into a discussion of tbese papers, but the fact is brought out that these insects orient themselves towards some definite object which is differentiated from its sur- roundings either by greater prominence or a difference in color. He not only cites instances of orientation towards trees, bushes, sign-posts, or even heads of grass, but others where the swarms hovered over paths through fields, or spots of different color but not elevated above the surroundings. The swarms over spots on the ground in all probability belong to different species from those attracted to prominent objects. Radl confesses that he made no attempt at close determination of the insects under ,observation and it is evident that he had no conception of the number of forms of similar but distinct habits that he might have before him. In consequence his statements are far too general and much that might have been used for or against his contention has escaped him.
Little as we yet know of the subject, it will be well to state right here that, even