Trioza struthanthi-group

Burckhardt, Daniel, Diaz, Fiorella & Queiroz, Dalva L., 2017, Four new neotropical Trioza species associated with Loranthaceae (Santalales) and comments on mistletoe inhabiting psyllids (Hemiptera, Psylloidea), Alpine Entomology 1, pp. 91-108 : 91-92

Trioza struthanthi-group

Diagnosis.

Adult. Body size small, 2.3-3.2 mm long. Genal processes developed, slender, 0.7-1.0 times as long as vertex along midline. Antenna ten-segmented, 1.3‒2.0 times as long as head width; with a single subapical rhinarium on each of segments 4, 6, 8 and 9. Forewing narrow, lanceolate, 2.5-3.0 times as long as wide; angular apically, with weakly curved vein Rs and small cu1 cell. Metatibia with genual spine and 1+3 apical spurs. Paramere incised apically. Female terminalia subglobular, proctiger with styliform process apically. Valvulae of ovipositor highly modified: dorsal valvula stylet-shaped; ventral valvula very broad, ribbon-shaped, obliquely truncate apically; lateral valvula ribbon-shaped, with two strongly sclerotised, teeth apically. - Fifth instar immature 1.5-1.7 mm long, 1.4-1.6 times longer than wide. Antennal flagellum 1-segmented. Forewing pad with humeral lobe extending forward almost to the middle of eye. Tarsi with triangular arolium, bearing short petiole and distinct unguitractor, claws fully developed and of similar size, small, shorter than arolium. Anus ventral; outer circumanal ring transversely reniform, consisting of a single row of pores. Marginal sectasetae truncate, densely spaced; postocular seta present; sectasetae absent from dorsum. - Host plants. Santalales .

Description.

Adult (Figs 1, 3, 5, 7). Body length 2.3-3.2 mm. Integument lacking macroscopic setae dorsally, mat with very fine scattered punctures. Head (Figs 2, 4, 6, 8) inclined at about 45° to longitudinal body axis; slightly wider than pronotum and about as wide as mesoscutum. Vertex trapezoidal, in the middle of each half slightly produced anteriorly; flat with weakly indented foveae; with sparse, moderately long microscopic setae; evenly curved down to genal processes; occipital margin relatively well-defined. Median suture fully developed, weakly incised in anterior half. Occiput forming narrow bands caudad of eyes, visible from above, weakly convex. Median ocellus directed forward, not visible from above, completely covering frons. Genal processes distinctly deflected from plane of vertex, 0.7-1.0 times as long as vertex along midline, bearing a long seta at base and a few long setae apically. Eyes hemispherical. Clypeus pear-shaped, bearing a pair of setae; ultimate rostral segment with each one pair of setae basally and in the middle, respectively. Antenna 10-segmented, 1.3-2.0 times as long as head width, with a single, subapical rhinarium on each of segments 4, 6, 8 and 9; segment 9 about as long as segment 10; segment 9 bearing two thick bristles, a longer one just proximal to rhinarium and a shorter one more towards the base of the segment; segment 10 with two terminal setae, one slender, subacute and about as long as segment, and the other one thicker, truncate and half as long as segment. Pronotum strongly curved down anteriorly, weakly arcuate in dorsal view. Mesopraescutum, in dorsal view, about 1.5 as wide as long, in lateral view relatively flat; anterior margin strongly arcuate. Forewing (Figs 9-16) narrowly lanceolate, subacute or narrowly rounded apically, 2.5-3.0 times as long as wide; veins beset with fine microscopic setae which are shorter than distance between setae, slightly denser at wing base becoming sparser towards apex; R branch acutangular, vein Rs weakly curved towards fore margin in apical third, branching of M on or close to Rs–Cu 1a line, vein Cu 4-5 times as long as Cu1b, cell m1 value 1.1-1.6, cu1 value 1.8-2.7; radular spinules covering narrowly triangular fields at the outer margins of cells m1, m2 and cu1. Hindwing 0.7-0.8 times as long as forewing, costal margin with 0-2 setae proximal to costal break, setae distal to costal break divided into two groups with 2-4 and 3-5 setae, respectively, as well as one seta at the end of sclerotised part of C+Sc; veins M and Cu with common stem. Hind leg with metacoxa bearing relatively short horn-shaped meracanthus, hardly produced at inner anterior trochanteral insertion; metatibia 0.7-0.9 times as long as head width, not inflated basally with genual tooth and 1+3 strongly sclerotised apical spurs. Abdomen with setae present on tergite 2 in male and tergite 3 in female. Male proctiger (Figs 17, 20, 23, 26) tubular, relatively short and thick, covered in long setae in apical two thirds along posterior margin. Subgenital plate subglobular, covered in moderately long setae. Paramere (Figs 18, 21, 24, 27) in profile, lamellar; incised apically with outer and inner lobe. Aedeagus with proximal segment slender, narrowly rounded basally; distal segment (Figs 19, 22, 25, 28) long and slender, longer than proctiger, weakly expanded apically; sclerotised end tube of ductus ejaculatorius short, weakly sinuous. Female terminalia (Figs 29, 32, 36, 39) subglobular, proctiger with styliform process apically. Proctiger with a few sparse, moderately long setae at and beyond the distal end of the circumanal ring and a few long, transversely arranged setae in the middle; circumanal ring oval, consisting of two rows of unequal pores (Fig. 31). Subgenital plate shorter than proctiger, subtriangular in profile, truncate or weakly indented apically in ventral view, evenly covered in moderately long setae basally and in the middle (Figs 38, 34, 37, 40). Valvulae (Figs 32, 35, 38, 41) highly modified: dorsal valvula stylet-shaped; ventral valvula very broad, ribbon-shaped, obliquely truncate apically with each a tooth apico-dorsally and apico-ventrally, respectively; lateral valvula ribbon-shaped, with two strongly sclerotised, teeth apically.

Fifth instar immature (Figs 42, 43). Body 1.5-1.7 mm long, in dorsal view, oval, 1.4-1.6 times longer than wide. Antennal flagellum one-segmented; cephalopronotal sclerite distinctly separated from mesonotal sclerite which is also separated from metanotal sclerite. Forewing pad 0.8-0.9 mm long, 2.3-2.8 times as long as antenna; humeral lobe extending forward almost to the middle of eye. Tarsi with triangular arolium (Fig. 47), bearing short petiole and distinct unguitractor, claws fully developed and of similar size, small, shorter than arolium. Caudal plate 0.7-0.8 times as long as wide; anus ventral; outer circumanal ring (Figs 48, 49) transversely reniform, distance between posterior margins of circumanal ring and of caudal plate 1.0-1.3 times as long as circumanal ring in longitudinal body axis; consisting of a single row of oval pores. Marginal sectasetae (Figs 44-46) truncate, evenly and densely spaced; postocular seta present; sectasetae absent from dorsum.

Comments.

Seven species are included: the North American Trioza acuminata Tuthill, 1943, stat. n., T. incidata Tuthill, 1945 and T. phorodendrae Tuthill, 1939, as well as the four South American species described below: T. struthanthi sp. n., T. tripodanthi sp. n., T. tristericis sp. n. and T. vagata sp. n. (Table 1).

Trioza acuminata Tuthill, 1943, was described as subspecies of T. phorodendrae Tuthill, 1939 based on a single male from California. According to Tuthill (1943) the genal processes of T. acuminata are distinctly longer than in T. phorodendrae suggesting that the two taxa are distinct. Until additional evidence becomes available, the two taxa are treated as different species and we elevate the former to species rank as Trioza acuminata Tuthill, 1943, stat. n.

Key to adults of the species of the Trioza struthanthi -group