Leucostoma acirostre Reinhard, 1956

Leucostoma acirostre Reinhard, 1956 View in CoL Leucostoma acirostre Reinhard 1956: 162 View in CoL

Diagnosis: The females are easily distinguished from other species of the genus as the tergite 6 pincers structures lack any denticules or strong setae on their inner margin. The males have some silver pruinosity on the abdomen, usually anteriorly on the last segments, as well as in the head. The male terminalia likely have some features that distinguish them from other Leucostoma species, but the single male was not dissected to compare.

Redescription: Male ( Figs. 2A–B View Fig , 3D View Fig ). Body length 4.5–5.2 mm.

Coloration: Head brown to black with strong silver and golden pruinosity; frontal vitta black. Antenna black; arista black. Palpus brown and prementum dark brown. Thorax black with silver pruinosity dorsally and laterally. Thoracic spiracles dark brown. Wing hyaline. Calypters white and partially hyaline. Halter dark brown to black. Legs dark brown to black; claws black; pulvilli pale brown. Abdomen black, tergites 3 to 5 anteriorly with silver pruinosity forming bands, stronger laterally.

Head: Holoptic. Eye bare. Frontal vitta narrow, slightly narrower than fronto-orbital plate maximum width. Ocellar setae lateroclinate. Eight frontal setae, descending to pedicel level. Inner and outer vertical setae hair-like, similar to surrounding postocular setae. Postocellar setae hair-like. Antenna inserted at middle level of eye, short, not extending to vibrissa level. Lunule setulose. Scape short, about one-quarter length of pedicel. Pedicel setose dorsally, with 1 strong seta. First flagellomere slightly longer than pedicel, elliptical but broader distally. Arista micropubescent. Parafacial bare. Vibrissa strong, 4–5 subvibrissal setae. Eye about 0.85 to 0.9 head height. Gena about 0.1 to 0.05 eye height. Antennal axis slightly shorter than oral axis. Lower facial margin protruding. Palpus slightly clavate. Prementum long, slightly longer than head height. Labella well-developed, as long as first flagellomere.

Thorax: Prosternum bare. Proepisternum bare. One strong proepimeral seta, surrounded with weaker setae. Anterior spiracle with both lappets well-developed, covering almost the entire opening. Posterior spiracle with posterior lappet slightly larger than anterior. Acrostichal setae 1+1, with another presutural long setula. Dorsocentral setae 2+3. Intra-alar setae 1+2. Supra-alar setae 1+2, the second postsutural short. Postpronotal lobe with 2 setae, and 3 anterior long setulae. One postalar seta. Scutellum with one basal, one lateral, one short subapical, and one decussate apical pairs of setae. Two katepisternal setae, with posterior seta longer. One anterior and five posterior anepisternal setae. One anepimeron seta. Katatergite and anatergite bare. Wing: subequal to thorax + abdomen length. Ratio of wing length/maximum wing width 2.4. Costal spine not differentiated. Costal vein without breaks, beyond intersection with vein Sc without ventral setulae. Cell r 4+5 with long petiole, petiole more than three times r-m length, ending before wing apex. Base of vein R 4+5 with 1 dorsal and ventral setae. Crossvein dm-cu slightly curved. Calypters rounded, large, almost reaching end of syntergite 1+2. Legs: Fore coxa with many anterodorsal setae. Fore femur with row of posterodorsal and posteroventral seta. Fore tibia with one posteroventral seta. Mid coxa with row of setae on anterior surface. Mid femur with rows of anteroventral and posteroventral setae on basal half, two posterodorsal preapical and one posterior preapical setae. Mid tibia with three anterior, two posterodorsal and one ventral setae. Hind coxa with row of anterodorsal setae. Hind femur with rows of anterodorsal, anteroventral and posteroventral setae on basal half, two anteroventral preapical setae. Hind tibia with three anteroventral setae, row of anterodorsal short setae with two strong, three posterodorsal setae. Tarsal claws long, subequal to combined length of fourth and fifth tarsomere.

Abdomen: Elliptical, slightly pointed at apex. Median marginal setae and lateral marginal setae on all tergites, row of marginal setae on tergites 4 and 5. Abdomen 1.8–1.95 times as long as wide, 1.1–1.25 times as long as thorax in dorsal view. Sternites completely overlapped by tergites. Sternite 5 plate-like, posterior margin slightly invaginated.

Terminalia: The single male was not dissected.

Female ( Figs. 2C–D View Fig , 3A–C View Fig ): Differs from male as follows. Head with only strong silver pruinosity and dichoptic. Ocellar setae stronger. Frontal setae stronger, with 6–7 setae, the posterior lateroclinate. Two proclinate fronto-orbital setae. Inner and outer verticals stronger, the latter directed laterally. Prementum slightly shorter. Thorax with stronger silver pruinosity; in presutural scutum sometimes delimiting two diverging median black stripes and two large lateral black spots. Three katepisternal setae. Wing slightly shorter, ratio of wing length/maximum wing width 2.6 to 2.7. Calypters slightly shorter. Fore tibia with three anterodorsal and one posteroventral setae. Mid tibia with four anterior setae. Tarsal claws shorter and more curved, pulvilli shorter. Abdomen with silver pruinosity band stronger on tergite 3, weak on tergite 4. Tergite 5 anterior part telescopically inserted in abdomen.

Terminalia ( Fig. 4A View Fig ): Terminalia. Sternite 5 plate-like. Tergite 6 strongly modified as two pincer structures; each posterior projection conical, without strong setae modified as spines, ending in 3 to 4 small projections; not fused dorsally; not fused to sternite 6. Sternite 6 subquadrate, not posteriorly invaginated. Tergite 7 divided in two separated pieces, with anterior elongation, and with a setulose lobe posteriorly. Sternite 7 as an elongated plate, with two short anterior projections; posterior margin deeply invaginated medially, forming two elongated lobes with setulae. Segment 8 fused; with a narrow-fused arch dorsally (probably part of tergite 8); ventral part elongated anteriorly, with a posterior bent piercer, projecting dorsally, then curving downwards (sternite 8). Epiproct and hypoproct not recognizable. Cerci elongate and thin, setulose posteriorly. Three spherical spermathecae.

Puparium ( Fig. 5A View Fig ): Elliptical, without horns or conspicuous spines. Posterior spiracle at the end of conical tubercle, with two very sinuous spiracle openings.

Distribution: U.S.A. ( O’Hara et al. 2020); Brazil new record.

Examined material: USA. Holotype, ò, Texas, Brownsville, iv.1929, Townsend col ( NMNH). BRASIL: 5ò, 4ñ, Pernambuco, Petrolina, UNIVASF ( CCA), 22.xi.2020, Martins, H.O.F. col ( MZSP); 1ñ, Mato Grosso do Sul, Cassilândia, Vinícius Souza, 3.ii.2022, (https://www.inaturalist.org/observations/106111066, photographic record, accessed on 12th July, 2024); São Paulo, São Paulo, Santo Amaro, R. Dios col. 1ñ ( MZSP), exit host: 30.i.2024, emerged from puparium: 9.ii.2024, host: Harmostes parafraterculus ; 1ò ( MZSP), 10.ii.2024; 1ñ ( MZSP), 30.xii.2023.

Host list

Hemiptera (Heteroptera) , Coreidae

Harmostes reflexulus (Say) ( Arnaud, 1978) Hemiptera (Heteroptera) , Rhopalidae

Harmostes parafraterculus Göllner-Scheiding new record