Jos. Bequaert.
A New Pseudomasaris from California, with some Considerations on the Masarid Wasps (Hymenoptera).
Psyche 36:61-88, 1929.

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PSYCHE
VOL. XXXVI
JUNE, 1929
No. 2
A NEW PSEUDOMASARIS FROM CALIFORNIA, WITH SOME CONSIDERATIONS ON THE MASARID
WASPS (HYMENOPTERA)
Department of Tropical Medicine, Harvard University Medical School, Boston, Mass.
While in Southern California, last spring, Professor W. M. Wheeler collected a large number of masarid wasps be- longing to two species, one of which appears to be new. I have used the opportunity offered by the description of this insect, to present a few remarks of a more general nature on the Masaridinse, by far the most interesting subfamily of diplopterous wasps. As I hope to show, their structure, habits and distribution exhibit a number of remarkable features that render the group worthy of consideration by the biologist.
Pseudomasaris (Pseudomasaris) wheeleri, new species (Fig. 1)
A large, minutely sculptured, dull species; black, with numerous and rather variable sulphur-yellow markings, the mesonotum with two complete or interrupted longitudinal stripes, the abdomen often with a Vespa-pattern. Length (h. + th. + t. 1 + 2) :
8, 10 to 10.5 mm.; 9,
9 to 12 mm. (total length, approximately 13 to 17 mm.) ; of wing 8,12.5 mm. and $ , 11 to 12.5 mm.
MALE.-H~~~ broadly elliptical in front view, about one and one-fifth times as wide as high; seen from above, about twice as wide as long, much narrower than the thorax. Oc- Pachc 3661-88 (1929). hup Yipsychc einclub orgrt(i/36-061.htiiil



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cipital margin of vertex far from the eyes, with a distinct inward curve, margined by a blunt carina which does not continue on the cheeks. Cheeks narrow, though distinct, about one-fourth the width of the eye in profile, gradually narrowed toward the vertex and evenly rounded in the lower half. Oculo-malar space short, but distinct, a little over one-fourth as long as the width of the mandibular articula- tion. Eyes more bulging than usual in the subgenus Pseu- domasaris, proper. Inner orbits more than three times as far apart at the clypeus as on the vertex, where the eyes are separated by about three times the diameter of a posterior ocellus. Frons flat, not carinate, very faintly raised between the insertions of the antennae, with the merest trace of a median tubercle in the center, shallowly concave below the anterior ocellus. Ocular sinus deep, bluntly rounded at apex Ocelli large, in a flattened triangle; the anterior ocellus much larger than the others, subcircular; posterior ocelli about twice as far apart as their diameter, barely separated from the inner orbits, distant from an imaginary line con- necting the posterior borders of the eyes by a little over twice their distance from each other. Interocellar area flat. Vertex strongly sloping posteriorly, slightly concave in front view. Antennae about four times as far apart as they are removed from the inner orbits. Clypeus strongly and evenly convex throughout, in outline flattened hexagonal with rounded upper angles, nearly one and one-half times as wide as long; the anterior, free portion about one-fourth shorter than the basal, interocular part; the upper margin slightly convex ; the upper lateral margins slightly oblique, very broadly separated from the eyes, the intervening space wider than the length of the oculo-malar space; the lower lateral margins slightly concave, ,forming almost right angles with the upper lateral margins; the truncate apex a little over half the maximum width of the clypeus, deeply, arcuately emarginate ; the apical angles very broadly rounded, with a translucent border. Antenna of 12 seg- ments, very long, shaped much as in P. occidentalis, but the third to seventh segments more slender than in that species ; the third to sixth not at all enlarged at their apices; the seventh slightly and evenly widened toward the apex, where



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19291 A New Pseudomasaris from California 63 it is less than half as wide as long; the terminal club of five very superficially separated segments, seen from above regularly short oval, sharply set off, much wider than thick, a little over one-half as wide as long, slightly longer than the sixth and seventh segments together, somewhat flattened dorsally, more convex ventrally where there is a slight Fig. 1. Pseudomasaris wheeleri J. Bequaert. Male: A, head in front view; B, abdomen in profile; C, left antenna from above; D, right middle tibia in front view; E, seventh tergite in profile; F, apical margin of seventh tergite in dorsal view; G, third sternite in profile; H, apex of process of third sternite in ventral view; I, right side of genitalia in profile, showing external view of valva externa (squama of Bradley); J, genitalia in dorsal view; K, internal view of left valva externa (Bradley's squama) , showing valva interna (Bradley's sagitta and volsella) .




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transverse depression close to the base. Mandibles folded beneath the labrum, smooth on the outer surface, ending in a long, finger-shaped, blunt apex, the inner margin with two faint denticulations before the apex. Thorax elongate rectangular, about one and one-fourth times as long as its greatest width, distinctly narrowed anteriorly and very slightly posteriorly, much lower than wide. Anterior margin of pronotum almost straight, rounded off, without carina or rim, slightly depressed in the middle; humeral angles slightly raised into blunt, broadly rounded humps. Meso- notum distinctly longer than wide, almost hexagonal in out- line, the anterior margin forming a very low outward curve ; slightly and uniformly convex in its anterior half, flattened in its posterior half; without traces of parapsidal furrows, but with a fine, incomplete furrow on each side in the post- erior half (above the tegula) and a fine, median somewhat raised line in the anterior half. Tegula about two and one- half times as long as wide; the outer margin shallowly notched before the middle; the apex covering the base of the scutellum on the side. Scutellurn very large, semi-ellipti- cal, with a broadly rounded apical margin which does not entirely cover the postscutellum in a dorsal view; evenly convex throughout, with a very low, blunt, somewhat elong- ate, median tubercle close to the anterior margin ; mesonotal suture not foveolate. Postscutellum very short; its median portion semi-elliptical from behind, divided into a very short, slightly swollen, anterior, horizontal portion (visible behind the scutellum from above) and a much longer, ver- tical, posterior area (in a plane with the concavity of the propodeum). Mesepisternum divided from the epimeron, but without a suture between the upper and the lower plates, without prepectal carina or suture and not depressed anteri- orly into epicnemia for the front legs; the usual impressed line marking the sternopleural suture, distinct. Propodeum short, squarely and vertically truncate behind, very slightly convex on the sides from above; dorsal areas broadly sep- arated from each other by the postscutellum, sloping gradually into the concavity (superior ridges not de- veloped) ; lateral ridges blunt; inferior ridges carinate, sharp; concavity wide, very shallow, with a deeper median



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19291 A New Pseudomasaris from California 65 depression which is divided by a low, blunt, longitudinal ridge starting behind the postscutellum and not reaching the a b d o m i n a l articulation ; lateral angle produced into a straight, broadly triangular, blunt, flattened tooth, directed posteriorly; the tooth continuous with the lateral ridge but set off rather sharply from the inferior ridge. Abdomen much elongate, of the shape usual in males of Pseudomasa- ris; the second, third and fourth tergites strongly con- stricted and depressed at the base. Armature of seventh tergite much as in P. occidentalis, but the preapical pair of tubercles longer and more finger-shaped, with a sharp carina at the base dorsally (in some specimens this carina is slight- ly more raised basad, behind a transverse depression of the tergite, on the spot where the fifth or sixth tubercle is situated in P. vespoides) ; the tubercles of the apical pair are also narrower than in P. occidentalis and are separated by a slight median projection of the hind margin. Second sternite slightly raised anteriorly, where there is a median notch separating two low tubercles (much less pronounced than in P. occidentalis and not continued posteriorly into blunt, oblique ridges as in that species). Process of third sternite in profile rather low and broad; its truncate sum- mit forming an almost equilateral triangle, with a broad, shallow depression ; its anterior angles bluntly rounded, without teeth; its posterior angle forming a short, but rather sharp tooth directed posteriorly (in general shape the process is more like that of P. vespoides than like that of P. occidentalis). Legs long and stout. Front femur and tibia slightly flattened beneath, their surfaces regular ; the tibia slightly swollen; all the segments of the front tarsus ciliate along the outer margin. Middle femur regular, slightly flat- tened beneath where the posterior margin shows a faint in- dication of a notch before the base; middle tibia in front view strongly widened on the inferior edge, the dilatation semi-elliptical in outline, broadly rounded off, placed about the middle of the length of the tibia, slightly flattened on the inner side. Hind femur and tibia regular; the tibia grad- ually and moderately widened toward the apical half; hind basitarsus regular, slender, straight, not appreciably flat- tened. Middle tibia with one apical spur; larger spur of hind



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66 Psyche June
tibia bifid at apex. Tarsal claws simple. Wings with the usual venation of Pseudomasaris; radial cell rather long and narrow; second cubital rather large, its length on the radius variable, often as long as the distance between the ends of the two recurrent veins on the cubitus; second intercubitus strongly bent below the middle. Genitalia (Fig. 1 I-K) essentially as in P. occidentalis.
Body mostly dull, densely and fairly uniformly covered with medium-sized and smaller punctures (visible with a hand-lens). Center of the frons more coarsely punctured. On mesonotum and scutellum the punctures are of two sizes, the larger ones especially numerous over the posteri- or portion of the mesonotum. Puncturation stronger on the basal constricted areas of the first three tergites than on the remainder of the abdomen. The following parts are impunctate and shiny: most of the outer surface of the mandible; the median depressed area of the concavity of the propodeum; a median, more or less triangular area at the base of the second to sixth tergites; and the middle of the seventh tergite very extensively at the base. Pubescence short, but rather abundant on head and thorax, sparser on the abdomen ; mostly grayish, a little darker on mesonotum and vertex. Posterior edge of middle femur with dense, somewhat silvery brown pile on the under side. Black, with the following areas sulphur-yellow : man- dibles (except the long black apices) ; labrum (except the ferruginous tip) ; clypeus (except the upper margin very narrowly and minute dots in the center) ; a double spot on the frons above the insertions of the antennee; the inner orbits from the base of the mandibles to the posterior ocelli, filling the ocular sinuses and widening on the frons to con- nect with the median spots; a small spot above each of the posterior ocelli; outer orbits, the yellow not reaching the vertex; most of the pronotum (except for a black, more or less triangular spot in the posterior half) ; a large spot in the upper part of the mesepisternum; tegulse; a spot on each side of the mesonotum close to the hind portion of the tegula; four elongate spots over the middle of the mesono- turn (forming two interrupted, diverging stripes) ; broad hind margin and extreme sides of scutellum ; extreme sides



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19291 A New Pseudomasaris from California 67 (lateral angles and ventral areas) of propodeum; broad apical bands on all tergites, those on the first to fourth very wide on the sides and abruptly narrowed, the median an- terior margin wavy; all the sternites (except for the bases and the apical depressed area of the process of the third sternite) ; and most of the legs (front coxae, trochanters and femora partly black above; middle and hind cox= and trochanters black beneath; under side of middle and hind femora with a narrow black line; tarsi partly ferruginous). On the fifth abdominal tergite the yellow is very extensive and partly divided in the middle by a sharp projection from the black base, while there is a free, ovate, black spot on each side in the yellow; the yellow band of the sixth tergite is similar to that of the fifth, but there are no free black spots ; the four tubercles of the seventh tergite are black and the two of each side are connected by a narrow black line. Antenna ferruginous to black; scape with a yellow apical band; third segment extensively yellow above; the fourth to sixth with some yellow streaks on the upper side; the club spotted with yellow at the base both above and beneath. Wings subhyaline, very slightly suffused with ferruginous brown in the costal, radial and first cubital cells and along some of the veins; the veins reddish brown, the stigma bright fulvous. The variations of the color in the males are slight: sometimes the frontal spots are much reduced or even lacking; the anterior margin of the postscutellum may be yellow in the middle; or the concavity of the propodeum may show two or three small yellow spots; the apical fasciae of the first four tergites instead of being wavy, may be more angularly emarginate anteriorly.
FEMALE.-A~~~~s in most respects with the male, except as indicated below. Occipital margin almost straight. Eyes not bulging. Inner orbits distinctly, though very little far- ther apart at the clypeus than on the vertex. Frons entirely flat, without even a trace of median tubercle. Ocular sinus broader. Ocelli subequal, in a flattened triangle ; the posteri- or ocelli a little closer to each other than to the eyes. Vertex flat, not sloping, without fovea. Antennae about five times as far apart as they are from the inner orbits. Clypeus



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68 Psyche [June
relatively longer, about one and one-third times as wide as long; the apical, free portion a little less than half the length of the basal, interocular part. Antenna as in the female of P. occidentalis, of 12 segments; scape more elongate than in the male; second segment very small ; third to sixth short, narrower than the remainder, which form an elongate-el- liptical swollen club not abruptly set off at base; third seg- ment slightly longer than the three following together. Man- dible with a very broad, bluntly rounded apex and the merest indication of two preapical denticulations on the inner margin. Humeral angles very evenly rounded, not humped. The lateral angles of the propodeum sharper than in the male. Abdomen of the normal shape, without con- strictions or processes ; the second and third tergites slightly depressed transversely near the base. Legs normal. Abdomen uniformly covered with minute punctures, without shiny areas at the bases of the tergites. Clypeus very coarsely punctate, the punctures even coarser than on the frons. Pilosity of the clypeus denser and longer than in the male.
Yellow markings more extensive and more variable than in the male. Tip of labrum, under side of antenna1 club and last segments of all tarsi partly ferruginous. The following areas are sulphur-yellow : mandible (except the broad black apex) ; most of labrum; clypeus (except for a median black mark in the form of a ring, a horse-shoe, or two half rings, sometimes reduced to four dots) ; inner orbits from man- dibles to vertex, broader above the ocular sinuses, but sep- arated from the frontal spot; a triangular spot on the frons, resting on the clypeus (sometimes reduced to two lines or to indefinite spots) ; outer orbits, not connected with the inner orbits; most of pronotum (a black stripe on each side, of variable width, often running from the anterior to the lateral margin, sometimes broken up in spots) ; most of mesopleura; tegulse; four longitudinal stripes on the meso- notum, one above each tegula (sometimes much shortened) and two in the middle, diverging and somewhat hooked anteriorly (very rarely broken up) ; broad hind margin of scutellum; postscutellum (in one specimen mostly black) ;



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19291 A New Pseudomasaris from California 69 most of the propodeum (sometimes with two or three black spots, rarely extensively black in the concavity) ; very broad apical margins to tergites one to five, variously marked with black as noted below; most of the sternites; and the legs (except for spots on the coxse and occasional spots or streaks at the base of some or of all the femora). In an ex- treme yellow example, the dorsal surface of the abdomen is almost wholly yellow, only the bases of the tergites being black and emitting black projections into the yellow; on the first and second tergites these projections are median only; on the third, fourth and fifth there are three black notches, one in the middle and one on each side; on the sixth a black median line connects the base with the apex of the tergite. In the extreme black specimens, the apical margins are slightly narrower and in addition to the black notches there is a transverse black spot in the yellow on each side of the first three tergites; these spots may be free or con- nected with the lateral notches; sometimes they are barely indicated or present on the first tergite only. Male, holotype, and female, allotype, in the Museum of Comparative Zoology, at Cambridge. Paratypes of both sexes will be deposited at the United States National Mu- seum, the American Museum of Natural History, the Philadelphia Academy of Natural Sciences, the California Academy of Sciences, and the British Museum. CALIFORNIA: Seven males (including the holotype) and fifty-four females (including the allotype), from Palm Springs, Riverside Co., collected by Professor W. M. Wheeler at flowers of Yerba Santa, Eriodictyon tomentosum Ben- tham, in April 1928.
Although the eyes of the male are much more bulging than is customary in the subgenus Pseudomasaris, proper, with the posterior ocelli almost touching the eyes which are only separated by three times the diameter of a posterior ocellus, it is impossible to include P. wheeleri in the sub- genus Holopticus, since the upper orbits are still far re- moved from the occipital margin. Moreover, the new species is very closely allied to P. occidentalis (Cresson), as shown



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70 Psyche [June
by a comparison of specimens.1 Both species have practi- cally the same peculiar structure of the legs in the male. Brad- ley (1922, Univ. of California Publ. Ent., I, No. 9, p. 424) writes of the male of P. occidentalis : "the middle tibia seen from in front with its inferior edge at the basal third strongly dilated and angulate." As a matter of fact, in that species the middle tibia is almost exactly as I describe and figure it for P. wheeleri. The two species are, nevertheless, readily separated in the males by the shape of the head (eyes not bulging in P. occidentalis, separated on the vertex by at least five times the diameter of a posterior ocellus, which is distinctly removed from the inner orbit), of the four tu- bercles of the seventh tergite (the preapical tubercles much shorter in P. occidentalis and not sharply carinate at the base), and of the process of the third sternite (in P. oc- cidentalis the summit is very narrow, with a longitudinal groove which is abruptly widened anteriorly). The slight differences in the genitalia to be noted between my figures of P. wheeleri and those given by Bradley for P. occidentalis (1922, Op. cit., PI. X, figs. 62-64) are probably accidental and due to the method of preparation. On the other hand, the females of the two species are structurally so much alike, that after a very careful comparison I can only point out the following differences: in P. occidentalis the vertex is wider, the inner orbits being there about as far apart as at the clypeus and the posterior ocelli being also distinctly more removed from the inner orbits than from each other; the clypeus is decidedly longer, being but little wider than long. Of course the coloration of the two species is strik- ingly different in both sexes.
Incidentally it may be noted that the character used by Bradley in his working key (1922, Op. cit., p. 381) to sepa- rate Masaris from Pseudomasaris, viz., postscutellum cov- ered or not covered by the scutellum, is not very reliable. In P. wheeleri the postscutellum may distinctly be seen in a dorsal view, protruding beyond the apex of the scutellum, although this is more marked in the male than in the female. 11 have been able to examine a pair of P. occidentalis, kindly loaned to me by the United States National Museum, through Miss Grace Sandhouse.




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19291 A New Pseudomasaris from California 71 The true distinguishing features between the two genera are, however, correctly given by Bradley in his synoptic table of the genera (1922, Op. cit., p. 389). The following records extend the known range of the genus and of some of the species. Some of the specimens belong to the collections of the Museum of Comparative Zoology at Cambridge (M. C. Z.).
1. P. vespoides (Cresson) .-ARIZONA: Grand Canyon. 1 8 (G. P. Engelhardt) . COLORADO : Cripple Creek Rd. (Cor- ley Mt. Highway), Teller Co., 8,930 ft., at flowers of Pents- temon glaber Pursh, 3 $ and 1 8, July 1, 1928 (J. Bequaert) the females disappear entirely within the flowers ; the males, however, were flying very swiftly from flower to flower in search of the females; it was noted that the smaller Pents- temon conf ertus Douglas, although much more abundant in that particular spot, did not attract any masarid. Plainview, Jefferson Co., 8 $ and 1 8, July 9 to 14, 1922 (G. P. En- gelhardt). Boulder, 1 $
(M. C. Z.). Platte Canyon, 1 $ (M.
C. Z.). Hall's Valley, 2 8, August. UTAH: Eureka, 1s (T. Spalding) (M.C.Z.). CALIFORNIA: Lakeside, 1s (E. P. Van Duzee)
(M. C. Z.) . Tallac, Eldorado Co., 6,000 ft., 1 Q (W. M. Giffard) (M. C. Z.).
2. P. texanus (Cresson) .-TEXAS: Waco, 2 (M. C. Z.).
3. P. zonalis (Cresson) .-COLORADO : Plainview, Jeffer- son Co., 4 s and 1 8, July 9 to 14, 1922 (G. P. Engelhardt). CALIFORNIA: Alta Mesa, 1 . WASHINGTON : Skagit Valley, 18 (M. C. Z.). BRITISH COLUMBIA: Princeton, 1,800 ft., I S (M. C. Z.).
4. P. edwardsii (Cresson) .-UTAH: Logan, 1 3 (E. S. G. Titus) (M. C. Z.). CALIFORNIA: Alpine, San Diego Co., IS
(E. P. Van Duzee) (M. C. Z.). Palm Springs, River- side, Co., 8 $, at flowers of Phacelia sp., April 1928 (W. M. Wheeler) .
5. P. marginalis (Cresson) .-COLORADO : Granite Peaks Camp on the Pine River, near Bayfield, La Plata Co., 9,000



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72 Psyche [June
ft., 18 Q , at flowers of Phacelia heterophylla Pursh, July 16 to 21, 1928 (J. Bequaert). These insects were active only during the warmest hours of the day and in bright sunshine. Most of the specimens were observed between 9 A.M. and 1 P. M. Although many other flowers were carefully watched for insect visitors and some species of Pentstemon were growing in that locality, P. marginalis was seen visiting only Phacelia heterophylla. No male was ever seen near the flowers.