New Neotropical Thysanoptera collected by C. B. Williams. II.
Psyche 34(6):230-246, 1927.
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230 Psyche [December
NEW NEOTROPICAL THYSANOPTERA COLLECTED BY C. B. WILLIAMS. I11
BY J. DOUGLAS HOOD,
University of Rochester.
The earlier paper of this series was published in Psyche, Vol. XXXII, pp. 48-69, 1925, and made known five new genera and thirty-six new species. During its preparation several doubt- fully distinct forms belonging to difficult genera were reserved for further study. Theseeleven in number-and one new genus, are described below. Two are named after their col- lector, whose careful field work has done much to increase our knowledge of the Thysanoptera of tropical America. The holotypes, allotypes, and a portion of the paratypes will remain in the collection of the author, Sericothrips williamsi sp. nov.
Female (macropterons) .-Length about 1.0 mm. Color yellow, paler by reflected light, with head, fore coxse, metascu- turn, and a narrow basal band (wider laterally) on tergites 2-6 of abdomen, brown; pronotal blotch conspicuous by reflected light, invisible by transmitted light, lateral margins straight and parallel, anterior margin roundly, and posterior margin sub- angulately, concave; antenna with segment 1 white; 2 and 3 gray, the latter darkened just beyond pedicel; 4-8 dark blackish brown, 4 and 5 with a light spot near base; legs yellow, with mid and hind femora brown at apex and mid tibise brown at base; fore wings grayish brown shading to nearly white in apical portion and pale also just beyond scale, darkest in scale and just beyond the subbasal pale band. Mouth cone long and slender, decidedly surpassing base of prosternum, heavily chitinized, la- brum nearly black apically. Antennae noticeably long and Contributions from the Entomological Laboratories of Cornell University.
19271 New Neotrapical Th ysanoptera 231
conspicuously slender, segment 3 about 3.5, and 4 nearly four, times as long as wide, 8 hardly four times as long as wide. Antennal segments: 1 2 3 4 5 6 7 8
24 36 67 60 51 54 11 15
Width (u) 27 26 19 16 15 15 6 4
Total length of antenna 0.32 mm.
Described from one female taken by Mr. C. B. Williams March 9, 1915, on the island of St. Croix, then Dutch, now American, West Indies.
It was found in sweepings from grass.
Aside from the differences in coloration, which are con- spicuous, this species may be known from tricinctus, undoubtedly its closest relative, by the very much longer and more acute mouth cone.
Sericothrips tricinctus sp. nov.
Female (macropterous) .-Length about 1.0 mm. Color pale yellow, with ocellar area, anterior half of pterothorax, and ab- dominal segments 2, 3, and 7 abruptly dark blackish brown; segment 8 of abdomen pale brown; pronoturn without trace of dark blotch; antennae with segments 1-3 nearly white, 3 grayish apically; 4-8 dark gray, with pedicel of 4 pale; legs pale yellow, hind femora and usually mid femora lightly brown at apex; fore wings brown at extreme base and in scale, nearly white in re- mainder of basal fourth, dark gray beyond, fading to white at tip. Mouth cone moderate in length, hardly attaining base of prosternum. Antennae very long and slender, segment 3 about 3.5 times as long as wide, and 8 more than four times as long as wide.
Antennal segments: 1 2 3 4 5 6 7 8
24 36 60 58 50 59 14 17
Width (p) 28 28 17 17 16 16 6 4
Total length of antenna 0.32 mm.
Described from several females collected by C. B. Williams in Martinique (type locality), Dominica, Guadeloupe, and Trini-
232 Psyche [December
dad. All except one, which was found in a flower of Hydrangea, were taken by sweeping grass.
The long, slender antennae and the coloration make this a very distinct species.
Sericothrips inversus sp. nov.
Female (macropterous) .-Length about 1.1 mm. Color by
transmitted light nearly uniform yellow, with a few brown spots on prothorax two on the metascutum, and one on each side of abdominal ter gites 2-7, behind a narrow, transverse, subbasal brown line; antennae gray in segments 1-3, the first palest, 2 and 3 lightly darkened at sides; 4-8 abruptly dark blackish brown, excepting distal constriction of 4, which is conspicously pale; legs pale grayish yellow, sometines lightly washed with brown; fore wings gray, darker in scale and shoitly beyond it, paler at tip. By reflected light, the color is nearly white, with a large gray pronotal blotch (which has a concave anterior margin and is darkest at anterior angles), two gray spots on metascutum, and the bases of abdominal tergites each with a narrow trans- verse gray band. Mouth cone very long and acute, attaining base of prosternum. Antennae long and slender; segment 3 about three times as long as wide, 4 decidedly narrowed in distal third, urn-shaped, 8 unusually slender, more than four times as long as wide.
Antenna1 segments: 1 2 3 4 5 6 7 8
24 42 62 52 48 54 14 19
Width (p) 27 26 19 19 16 16 6 4
Total length of ant,enna 0.32 mm.
Described from several females taken by Mr. C. B. Williams in Dominica and Trinidad, by sweeping grass. The coloration of the antennae-abruptly dark brown in segments 4-8, save for the pale gray apex of segment 4, which is decidedly narrowed-should serve for its recognition. The sec-
ond segment of the antenna is longer than usual in this portion of the genus, and segment 8 is especially long and slender.
New Neotropical Thysanoptera
Hercothrips gen. nov.
(+K, a net; Opq, a wood worm.)
Body reticulate, at least in head and thorax, abdomen fre- quently striate.
Head always broader than long, with vertex elevated between eyes but not produced to overhang insertion of antennae. Eyes usually distinctly protruding, pilose. Ocelli ap- proximate, borne on the elevated vertex. Antennae eight-seg- mented, with segment 1 small, 2 much longer and broader, 3 and 4 stem-like at either end and with forked trichomes. 6-8 close- ly united, 8 long and slender. Maxillary palpi two-segmented. Prothorax strongly transverse, shorter than head, without strong bristles, notum foveate. Hind cox2 approximate, separated by a fraction only of their transverse width. Wings slender, not conspicuously broadened at base nor much narrowed beyond it, with two longitudinal veins frequently united with ambient vein; costal bristles and costal fringe distinct, subequal in length. Ab- domen not sharply constricted basally; tenth segment rarely divided above.
Genotype : Heliothrips striatus Hood.
The following species are known to belong here: aulmanni (Karny) , bicinctus (Bagnall) , brunneipennis (Bagnall) , cincti- pennis (Hood), fasciapennis (Hinds), fasciatus (Pergande) , femo- ralis (Renter), indicus (Bagnall) , marginipennis (Hood), minu- tissimus (Bagnall) , pattersoni (Bagnall) , phaseoli (Hood), puncti- pennis (Hood), sculptilis (Hood), striatopterus (Kobus) , and striatus (Hood), in addition to the five new species described in this paper.
It will be noted that Hercothrips comprises essentially those species which we used to place in Heliothrips, minus the genotype hmorrhoidalis. In Heliothrips as now restricted, is found a some- what different type of wing, lacking as it does the costal fringe of bristles and having the anterior vein separate from the ambient vein through most of its length, as well as being de- cidedly broadened basally. In Heliothrips, too, the third and fourth antenna1 segments are differently formed and lack the forked trichomes of Hercothrips, while the metascutum is more differentiated, with an elevated triangular central area which
234 Psyche [~ecember
overhangs laterally and posteriorly and serves in this way to hold the wings more firmly in position. Most important of all, however, is the closely approximate condition of the hind cox% of Hercothrips-a type of structure which I have learned to associate with the jumping habit, but with what degree of ac- curacy I am not sure.
Selenothrips is perhaps the closest relative of Hercothrips; but in it is found a fore wing with conspicuous, enlarged bristles on the costal margin and on the two longitudinal veins, many of them much longer than the width of the wing; a pronoturn which instead of being reticulate is transversely striate; and an abdomen in which the distal segments are shortened. Hercothrips insularis sp. nov.
Female (macropterous).-Length about 1.1 mm. Color nearly blackish brown, head and thorax not noticeably paler; coxse brown; fore and mid femora yellow,
shaded with brown at
middle, hind femora yellow at base and blackish brown beyond; tibiae yellow at either end, brown between, hind pair darkest; tarsi lemon yellow; fore wings brown at base (excepting costal margin and end of scale), with a narrow nearly white band just before the fork in the principal vein, nearly uniform brown beyond, very slightly paler toward tip of wing, ambient vein in distal eighth of wing and all veins in third eighth, dark blackish brown; antennae with segments 1, 2, and 6-8 blackish brown, 1 paler; 3-5 pale yellowish, indistinctly darkened apically. Head broadest across eyes, 1.25 times as wide as long, cheeks nearly straight, curving slightly to eyes and to base; dorsal surface reticulate (though not deeply) with faint indication of occipital line, roughened within the reticules; frontal costa nearly as wide as first antenna1 seg- ment. Eyes about 0.6 as wide as their interval, of normal struc- ture. Ocelli of normal form and position. Antennae normal, segments formed almost exactly as in phaseoli2 Prothorax with reticulation much like that of head. Metascutellum distinct'ly reticulate except at sides. Fore wings with bristles and veins as See Psyche, Vol. XIX, PI. 8, fig. b; 19 12.
19271 New Neotropical Thysanoptera 235
in phaseolL3 Abdomen reticulate, not striate, strongly roughened within the reticules; segment 10 divided dorsally to near base. Measurements of holotype ( Q ) : Length 1.13 mm.; head, length 0.118 mm., greatest width (across eyes) 0.148 mm., least width (at posterior angles of eyes) 0.136 mm. ; eyes, length 0.068 mm., width 0.040 mm., interval 0.068 mm.; prothorax, median length of pronotum 0.108 mm., width 0.195 mm. ; ptero- thorax, width 0.230 mm. ; fore wings, length 0.780 mm., width at middle 0.042 mm., width near base 0.068 mm. ; abdomen, greatest width 0.269 mm. ; segment 8, length to fringe 0.078 mm., segment 9, length 0.114 mm., segment 10, median length 0.056 mm.
Antenna1 segments: 1 2 3 4 5 6 7 8
20 40 46 40 33 27 15 31
Width (p) 24 28 21 21 20 17 7 5
Total length of antenna 0.25 mm.
Described from a number of females collected in St. Croix (type locality), Grenada, Tobago, Martinique, Trinidad, Porto Rico, and Cuba, by C. B. Williams, F. W. Urich, T. H. Jones, and S. C. Bruner. Most of the specimens were taken by sweep- ing, though the Cuban and Porto Rican ones came from corn, sugar cane, and possibly from molo jillo. This is a member of the group which includes fasciatus. The long head will distinguish it from that species, while the italicized characters will serve for its separation from cinctipennis, to which it is more closely allied.
Hercothrips nanus sp. nov.
Female (macropterous).-Length about 0.84 mm. Head and thorax brownish yellow, the head darkened with brown in pos- terior half and with a narrow, nearly black line along posterior margin, the thorax darkened with brown along sides and in an- terior portion of mesothorax, dorsum of metathorax very pale; abdomen with segment 1 concolorous with dorsum of metathorax, 2-8 dark brown, and 9 and 10 pale brown; antennae with segments 31J. c., PI. 8, fig. a.
236 Psyche [December
1 and 2 gray or very pale brown, 3-5 pale gray with apices (par- ticularly of 3 and 4) darker, and 6-8 dark gray-brown; femora pale brown, mid and hind pairs with their apical thirds nearly colorless; tibiae pale yellowish, with a brown band at middle; tarsi pale yellow; fore wings clear white in basal third, dark gray brown in middle third, and white in apical third save the tip, which is dark gray brown. Head about 1.5 times as wide as long; cheeks nearly straight, rounded to eyes and slightly con- verging posteriorly; dorsal surface distinctly but not conspicuous- ly reticulate, roughened between the lines of reticulation; frontal costa broad, 1.2 times as wide as first antennal segment, the interval between antennas fully 1.3 times the width of first antennal segment; vertex subcarinate in front of ocelli. Eyes not prominently protruding, pilose. Ocelli approximate, opposite center of eyes. Antennae, about 2.1 times as long as head, formed almost exactly as in phaseolQ but slightly stouter. Prothorax more than twice as wide as long, shorter than head and with similar reticulation. Wings of fore pair 13 times as long as width at middle, venation as usual; principal vein at base with five bristles, the first three of which are slender and white, the other two stout, approximate, nearly black, and situated at the fork; anterior vein with two bristles near apex, the latter one nearly black; posterior vein with four equidistant bristles at middle, the second and fourth ones nearly black and situated, respectively, near the outer margin of the dark band and at the middle of the white band. Abdomen with tergites 2-8 closely striate laterally, the striae transverse toward middle of segments and longitudinal at sides, almost exactly as in phaseoZi;5 tergite 10 without longitudinal dorsal suture, though irregularly weakened toward tip.
Measurements of holotype ( 9 ) : Length 0.84 mm. ; head, length 0.102 mm., greatest width (behind eyes) 0.157 mm., least width (across eyes) 0.151 mm. ; interval between antennae 0.03 1 mm. ; eyes, length 0.065 mm., width 0.038 mm., interval 0.075 mm. ; prothorax, median length of pronotum 0.081 mm., width 0.176 mm. ; pterothorax, width 0.228 mm. ; fore wings, length 4See Psyche Vol. XIX, PI. 8, fig. b; 1912. 'L. c., fig. c.
19271 New Neotropical Thysanoptera 237
0.585 mm., width at middle 0.045 mm., near base 0.061 mm.; abdomen, width 0.236 mm.
Antenna1 segments: 1 2 3 4 5 6 7 8
17 34 43 37 30 23 10 23
Width (p) 23 28 21 21 18 16 7 4
Total length of antenna 0.22 mm.
Described from 18 females from Trinidad and Tobago, British West Indies, taken by F. W. Urich and C. B. Williams, respectively, principally on a wild vine belonging to the genus Couania.
Very close to phaseoli, but the smaller size and the italicized characters will separate them readily.
Hercothrips masculinus sp. nov.
Female (macropterous) .-Length about 1 mm. Color uni- form gray brown, ocellar pigment dull orange yellow by trans- mitted light, lemon yellow by reflected light; antennae largely brown and nearly concolorous with body, segment 1 paler, 2 dark blackish brown; 3 with stem white, globose portion and apex gray brown; 4 with brief pedicel nearly white, remainder dark blackish brown, but paler basally; 5 clear white except for a slight brownish cloud at extreme apex; 6-8 dark blackish brown; legs largely brown, knees, tarsi, and most of fore tibiae pale yellow; fore wings dark gray brown, with a narrow white band just beyond scale and another in eighth tenth, a few darker streaks at base and a small slightly elevated dark spot on the costal margin just beyond the pale subbasal band, this spot darker be- cause covered with longer and heavier pubescence than the rest of wing, all veins darker, especially the ambient vein at tip of wing, scale paler. Dorsal surface of head and thorax, lateral thirds of abdominal tergites 1-8, and a narrow median portion of tergites 1 and 2, with dark polygonal reticulation, surface rough- ened within the reticles. Head broad, without occipital line or neck-like constriction, cheeks nearly straight but somewhat con- verging posteriorly, rectangularly narrowed to eyes; ocellar area opposite center of eyes, slightly elevated but not produced no
238 Psyche [December
overhanging. Antennae separated by somewhat more than the width of segment 1; segments 3 and 4 much as in phaseoli6 but more globose and with the pedicel of 4 more abrupt and shorter; 5 slightly slenderer; 8 longer and slenderer; 3 and 4 with forked trichomes. Wings of fore pair with about 18 short, inconspicuous bristles on costal margin, those in basal portion of wing half as long as distal ones and less than half the width of wing, fringe about as long as distal bristles; anterior vein with one near fork and ' one near tip, very inconspicuous and pale; posterior vein with about five similar bristles. Abdomen with segment 9 long, 2.5 times the length of 10 and about 1.2 times as wide at base as long, width at apex (across bases of lateral bristles) about 0.66 that at base, its inner pair of dorsal bristles shorter than outer, which are slightly longer than segment 10, both pairs approximate and dis- posed in a straight transverse line.
Measurements of holotype ( 9 ) : Length 1.05 mm. ; head, length 0.118 mm., greatest width (behind eyes) 0.174 mm., least width (at base) 0.160 mm. ; eyes, length 0.072 mm.. width 0.044 mm., interval 0.080 mm.; prothorax, median length of pronotum 0.104 mm., width 0.212 mm. ; pterothorax, width 0.255 mm. ; fore wings, length 0.735 mm., width at middle 0.044 mm., near base 0.057 mni. ; abdomen, width 0.261 mm.; segment 8, length to fringe 0.078 mm. ; segment 9, length 0.128 mm., width at base 0.156 mm., width across bases of lateral bristles at apex 0.104 mm. ; segment 10, length 0.050 mm., width at base 0.082 mm.
Antenna1 segments: 1 2 3 4 5 6 7 8
43 38 35 22 8 25
Width (p) 23 30 22 21 18 17 9 5
Total length of antenna (approximate only) 0.23 mm. Described from a unique female taken from bamboo at St. Annes, Trinidad, in the British West Indies, March 28, 1915, by C. B. Williams LC. B. W. No. 6121.
The elongate and only slightly tapering ninth abdominal segment seems to be unique in the genus, occurring in none of 6See Psyche, vol. XIX, PI. 8, fig. b; 1912.
New Neotropical Thy sunoptera
the other fourteen species before me, and aids in giving the female a most decidedly male-like appearance when seen under a low-power objective. Other important differentiae are those italicized above.
Hercothrips williamsi sp. nov.
Female (macropterous) .-Length about 1.05 mm. Color dark brown (nearly black to the naked eye), darkest in ab- dominal segments 5 and 6, head yellow between eyes, save for the ocellar area and a narrow brown line from it to the frontal costa; antennae with segment 1 brownish yellow; distal constriction of 3, pedicel and distal constriction of 4, and all of 5 clear white, the intervening portions dark blackish brown; legs blackish brown, the mid and hind pairs darkest; tarsi and tips of tibiae yellow; fore wings dark brown, paler between veins and in a narrow trans- verse band just beyond scale; with a darker streak at base in front of longitudinal vein and a small, round, slightly elevated * dark spot on the costal margin just beyond the pale subbasal band, this spot darker because covered with longer a,nd heavier pubescence than the rest of the wing. Dorsal surface of head, thorax, and median portions of abdominal tergites 1 and 2 with conspicuous subequal polygonal reticulation, formed by raised black chit' linous lines, not roughened between the lines of reticulation. Head broad, with a prominent lateral stvdhzg at anterior end of cheeks, sides abruptly converging posteriorly to a transverse groove on each side which shallows dorsally and disappears before attaining the median line; ocdlar area opposite center of eyes, slightly elevated but not at all produced nor overhanging, with a narrowly pooved ridge running from it downward to frontal costa. An- ten,n,~~ separated 'by 1.8 times width of segment 1 ; segments 3 and 4 with a subglobose middle portion, pedicels slender, distal portions slender and much prolonged; forked trichomes on 3 and 4 ex- ceptionally long. Wings of fore pair with about 20 dark bristles on costal margin, averaging fully as long as width of wing and subequal in length to fringe; anterior vein with one similar bristle near fork and 3 in distal fourth of wing; posterior vein with about 8 equally spaced bristles; about four bristles on vein
240 Psyche [December
basal to fork.
Abdomen with last segment short and broad; tergites 2-7 striate, rather than reticulate, at sides, the lines curving outward and backward; bristles not long, yellowish and incon- spicuous.
Measurements of holotype ( 9 ) : Length 1.05 mm. ; head, length 0.140 mm., greatest width (behind eyes) 0.196 mm., least width (across eyes) 0.184 mm.; eyes, length 0. (J82 mm., interval 0.096 mm.; prothorax, median length of pronotum 0.102 mm., width 0.220 mm. ; pterothorax, width 0.293 mm. ; fore wings, length 0.810 nim., width at middle 0.044 mm. ; abdomen, width 0.318 mm. ; segment 9, length 0.116 mm. ; segment 10, length 0.049 mm., width at base 0.080 mm.
Antenna1 segments: 1 2 3 4 5 6 7 8
24 48 73 58 40 34 16 30
Width (/J) 26 32 24 23 17 16 8 5
Total length of antenna 0.32 mm.
Described from a ufique female taken at St. Annes, Trinidad, in the British West Indies, March 28, 1915 by C. B. Williams, from an unidentified plant. [C. B. W., No. 614.1 A very distinct and most interesting species, resembling brunneipennis in wing coloration but related more intimately to striatus, phaseoli, and their allies. The sculpture, large head, an- teriorly tubercled cheeks, and peculiarly colored antennae are distinctive.
Hercothrips funebris sp. nov.
Female (macropterous) .-Length about 1.1 mm. Color near- ly black (quite so in abdomen), head and thorax paler; antennae brown, with segments 1 and 2 paler, and the basal half of 3, basal third of 4, and basal two-thirds of 5, grayish white; fore legs brown, with trochanters, tips of tibiae, and tarsi pale yellow, nearly white; mid and hind legs similarly colored, but with the dark portions nearly black; fore wings nearly uniform dark brown, with a pale transverse band just beyond scale, with a dark streak at base in front of principal vein and another be- hind it, and with the costal half of wing just beyond the pale band and the extreme tip, nearly black. Dorsal surface of head,
19271 New Neotropical Thysanoptera 24 1
thorax, and abdomen strongly and prominently reticulate with heavy black lines, not roughened between the lines of reticula- tion, except for a few dots in basal reticules of head. Head broad, cheeks rounded and swollen, with a strong neck-like con- striction which is bounded in front by a heavy chitinous line. Antennse separated by about 1.7 times the width of segment 1, formed almost as in phaseoliJ7 forked trichomes on 3 and 4 ex- ceptionally long, that on 4 attaining apex of segment 5. Meta- scutum without differentiated triangle; metascutellum strongly reticulate. Wings of fore pair with about 22 inconspicuous brown bristles on costal margin, averaging in length less than the width of wing, fringe fully twice as long; anterior vein usually with one similar bristle at the fork and four in distal half; post- erior vein with about eight and principal vein with six. Ab-
domen of normal form, opaque black, reticulation coarse and heavy, not absent from middle portions of tergites but extending entirely across them and strongest just beyond the irregular, subbasal, transverse line; segment 10 with an irregular dorsal suture in apical half; all abdominal bristles pale and short. Measurements of holotype ( 9 ): Length 1.08 mm., head, length 0.105 mm., greatest width (behind eyes) 0.176 mm., least width (near base) 0.135 mm.; eyes, length 0.085 mm., width 0.045 mm., interval 0.087 mm.; prothorax, length 0.102 mm., width 0.201 mm. ; pterothorax, width 0.267 mm. ; fore wings, length 0.780 mm., width at middle 0.041 mm., near base 0.067 mm.; abdomen, width 0.300 mm., segment 8, length to fringe 0.076 mm. ; segment 9, length 0.087 mm. ; segment 10, length along median dorsal line 0.036 mm.
Antenna1 segments: 1 2 3 4 5 6 7 8
24 41 59 49 36 28 12 25
Width (u) 24 30 22 23 20 17 8 5
Total length of antenna 0.27 mm.
Male (macropterous) .-Length 0.87 mm. Color of body and appendages like that of female. Tergite 9 with the two pairs of bristles slender, the inner pair shorter, slenderer, and with their bases more distal, the four thus being disposed on a semicircle. 'See Psyche, vol. XIX, PI. 8, fig. b; 1912.
242 Psyche ' [December
Described from one female and one male, taken by J. B. Rorer at Hacienda Pretoria, near Barraganetal, Equador, De- cember 29, 1917, on "cojojo" [C. B. Williams, No. 1058.1 Close to errans and brunneipennis, but differing from both in the non-specialization of the metascutum, the clouded an- tennae, the incompletely divided tenth abdominal segment, and various other details.
Tryphactothrips lineatus sp. nov.
Female (macropterous.-Length about 1.05 mm. Dorsal surface deeply reticulate. Color yellowish brown, with head, prothorax, middle of pterothorax, and last two or three ab- dominal segments more yellowish; segment 10 of abdomen gray in apical sixth; antennae yellow, with segment 2 decidedly darker than 1 and brownish at sides and base, 3-5 clear lemon yellow, 6-8 blackish brown excepting yellowish base of 6; fore legs yellow with tibiae shaded with blackish brown on inner surface, mid and hind legs brown with tarsi, knees, and bases of femora yellow; fore wings yellowish at base and along veins, with two indistinct brown bands, one occupying the third tenth, the other the seventh tenth, and with two or three very faint maculations between the bands and one at extreme tip of wing, all of these wing markings produced by darker pubescence; wing bristles nearly black in basal half, nearly white beyond. Vertex produced, overhanging insertion of antennae; occiput without a crescentic series of large reticulations; antennae eight-segmented ; segment 1 short, sub- cylindrical, about as broad as long; 2 broadest in entire antenna; 3 slender, vasiform, about 4.3 times as long as wide ; 4 asym- metrical, swollen on outer surface; 5 clavate, broadest at apical fourth or fifth; 6 with a stout pedicel which is nearly twice as thick as that of 5, somewhat obliquely united at apex to 7, the two forming a compact mass ; 8 slender, about six times as long as basal width; sense cones slender, those on 3 and 4 bifurcate beyond base (Y-shaped) . Mesoscutum without median suture, but acutely notched behind. Wings of fore pair with first longi- tudinal vein united with ambient vein, posterior vein not so united, one bristle at their fork and three basally; anterior vein
19271 New Neotropical Thysanoptera 243
with six bristles beyond fork and posterior vein with seven or eight, positions not constant; all wing bristles long, broad, flat- tened, and dilated, as long as width of wing at middle. Abdomen strongly and sharply constricted at base of segment 2, which is the longest in the entire abdomen; dorsal surface with the usual deep, prominent reticulation at sides, but with the dorsal surface of segments 3-7 with three or four perfectly parallel transverse lines at base, between the areas of reticulation; segment 10 long, tubular, reticulate, somewhat constricted at base, divided above by a longitudinal suture; bristles at apex of segment 9 about one- half as long as 10.
Measurements of holotype ( $ ) Length 1.05 mm.; head, length 0.100 mm., greatest width (across eyes) 0.172 mm., least width (near base) 0.152 mm. ; eyes, length (approximate) 0.092 mm., width (approximate) 0.040 mm. ; prothorax, median length of pronotum 0.090 mm., width 0.180 mm. ; pterothorax, width 0.248 mm.; fore wings, length 0.780 mm., width at middle 0.046 mm., just beyond scale 0.076 mm.; abdomen, width 0.285 mm.
Antenna1 segments: 1 2 3 4 5 6 7 8
20 34 65 42 36 25 12 30
Width (u) 24 30 15 17 18 17 11 5
Total length of antenna 0.26 mm.
Trinidad; C. B. Williams; on an unidentified plant. This is the only New World species with eight-segmented antennae.
The curious transverse lineation of the abdomen is also distinctive.
Tryphactothrips brevipilus sp. nov.
Female (macropterous}.ÌÔLengt about 1.04 mm. Dorsal surface deeply reticulate.
Color yellowish brown, with middle
of pterothorax and last three or four abdominal segments paler and more yellowish; segment 10 of abdomen sha,ding to gray in apical fourth; antenna yellow, with segment 2 decidedly darker than 1 and brownish at sides and base, 3-5 pale lemon yellow except apex of 5 which is washed with gray, 6 yellowish gray;
femora yellowish brown, paler at base and sometimes at apex, middle pair lightest; tibise yellow at base and apex, brown be- t,ween; tarsi lemon yellow; fore wings brown in first tenth (ex- cept the yellowish costal margin and the paler outer half of scale) and with brown bands (due to dark pubescence) occupying most of the third tenth, all of eighth tenth, and the extreme tip of wing, between the bands with three or four faint maculations, the veins somewhat darkened with brown; bristles on veins of wings unicolorous, brown. Vertex strongly produced, about at- taining second segment of antenna, overhanging. Antennae six- segmented, segment 5 with a more or less distinct transverse suture at distal third; segment 1 short, subcylindrical, about as broad as long; 2 broadest in entire antenna; 3 slender, vasiform, about 4.6 times as long as wide; 4 asymmetrical, swollen on outer surface, with a rather long and slender pedicel; 5 subfusiform, pedicellate; 6 long and very slender; sense cones slender, those on 3 and 4 bifurcate beyond base (Y-shaped). Mesoscutum with a longitudinal, median suture extending nearly to anterior mar- gin, the reticles on either side with their inner margins not at all deflected posteriorly. Wings of fore pair with first longitudinal vein united with ambient vein, posterior vein free, one bristle at their fork and three basally; anterior vein and costa together with about eleven bristles beyond fork, the two series indis- tinguishable; posterior vein usually with six bristles beyond fork; all wing bristles short, stout, but not dilated, averaging about one-half as long as width of wing at middle. Abdomen strongly and sharply constricted at base of segment 2, which is the longest in the entire abdomen; dorsal surface with the usual deep, prominent reticulation at sides, the intervening portion with transversely elongate polygons of reticulation arranged in regular transverse rows; segment 10 nearly tubular, about three-fourths as long as prothorax, not constricted at base, reticulate, divided above by a longitudinal suture; bristles at apex of seqment 9 about one-third as long as 10.
Measurements of holotype ( 9 ) : Length 1.04 mm. ; head, length 0.116 mm., greatest width 0.190 mm. ; eyes, length 0.056 mm., width 0.042 mm., interval 0.101 mm. ; prothorax, length 0.106 mm., widt'h 0.183 mm. ; pterothorax, width 0.266 mm. ;
19271 New Neotropical Thysanoptera 245
fore wings) length 0.720 mm.) width at middle 0.041 mm., near base 0.076 mm. ; average length of bristles near middle of wing 0.020 mm. ; abdomen, greatest width 0.293 mm. Antenna1 segments: 1 2 3 4 5 6
24 40 73 43 59 28
Width (p) 26 31 16 19 20 5
Total length of antenna 0.27 mm.
Trinidad: (2. B. Williams; on creepers) bushes) and a leaf of Arum ' Lily.
The characters italicized in the description separate it from constrictus, the only New World species with which it agrees in the possession of six-segmented antennz and a divided mesoscu- tum.
Eurythrips cinctus sp. nov.
Female) jorma rnacr0ptera.-Length about I. 16 mm. Color yellowish brown) wit?i transparent red subhypode~mal pigmenta- tion) sides of head and all of thorax and apical abdominal seg- ments darker? the base of abdomen (especially sepents 2 and 3) decidedly puler and almost free of red pigmentation, giving the insect a distinct yellowish band at middle; anfienn~ nearly uni- jorrn blackish brown; somewhat paler in basal portion of segment 1, apical portion of 2) and pedicel of 3; femora brown, shading to lemon yellow beyond middle of tibiz; fore wings pale brown) (decidedly darker at base. Head nearly 1.2 times as long as greatest widt.h; ocelli rather widely separated) nearly touching margins oj eyes) the interual between posterior0 celli about 0.54 that between eyes; postocular bristles about 0.4 as long as head) pointed or very nearly so; postocellar bristles very minute? about attaining posterior margins of posterior ocelli; mouth cone broadly rounded) somewhat surpassing middle of proster- num; prothorax with anterior marginal bristles minute) all others long, pale) and very nearly pointed; fore tarsus with a small) claw-like, somewhat forwardly-directed tooth arising from the inner distal angle of the first tarsal segment; fore wings with- out accessory hairs at tip and with the three subbasal bristles .short) slightly dilated apically.
246 Psyche [De~mber
Measurements of holotype ( Q ) : Length I. 16 mm.; head, length 0.165 mm., greatest width 0.139 mm., least width (across eyes) 0.131 mm.; eyes, length 0.046 mm., width 0.035 mm., in- terval 0.061 mm.; postocula~ bristles, length 0.068 mm,; pro- thorax, length of pronotum 0.120 mm., width across cox% 0.240 mm. ; pterothorax, width 0.248 mm. ; abdomen, greatest width 0.300 mm. ; tube, length 0.124 mm., width at base 0.071 mm., at apex 0.035 mm.
Antenna1 segments: I 23 4 56 7 8
40 48 51 48 50 46 44 34
Width 38 32 32 31 30 26 25 16
Total length of antenna 0.36 mm.
Female, ,forma brachyptera.-Apparently identical with the macropterous form except for the following: Legs much paler, the tibis, tarsi, and distal portions of femora lemon yellow; ocelli wanting; wings reduced, the fore pair represented by a pair of small oval brown pads, each with two rather long, nearly pointed bristles.
Described from three females taken by Mr. C. B. Williams at Caura Valley, Trinidad, British West Indies, April 20, 1916, by sweeping grass.
Very close indeed to E. harti, but readily known by the italacized characters.
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