Dixella woodi Chaverri & Borkent, 2007

Dixella woodi Chaverri & Borkent, 2007 View in CoL ( Figs. 1–3 View Figure 1 View Figure 2 View Figure 3 )

Diagnosis. Adult. Only species of Dixella in Neotropical Region with katepisternum having patch of elongated setae on medial portion. Female: Sternite IX with medial portion tapered and slender (V-shaped) with undulating sides, lateral portion anteriorly wider, featuring ventral and laterally tapered projections. Segment X very elongated, extending beyond the apical portion of the cercus. Male: Gonocoxite with apical lobe with expanded apical portion with three subbasal setae (two in posterior portion and one in anterior portion) and one elongate basal seta.

Description of Female. ( Figs. 1–2 View Figure 1 View Figure 2 ). Body length: 4 mm (n= 1). Head ( Figs. 1B–C View Figure 1 ) dark brown with setae around the eyes in the posterior portion. Scape collar-like. Pedicel globose, 0.45x length of flagellomere I. Flagellum light brown with 14 flagellomeres.Flagellomere I slightly cylindrical, 1.5x length of flagellomere II. Flagellomere XIV with pair of divergent apical setae. Clypeus brown, subquadrate, with ca. 15 setae in the medial portion. Maxillary palp I–III ratio (1, 1.5, 3.5), missing the IV–V. Thorax ( Fig. 1F View Figure 1 ). Scutum light brown with three brown stripes: one medial extending from anterior to middle portion as longitudinal slender strip; two brown longitudinal lateral stripes extending from prescutal to prescutellar area (dorsal view). Acrostichal and dorsocentral setae complete; antealar area with ca. 15 scattered setae. Antepronotum setose subtly darker than postpronotum. Postpronotum brown with five setae. Anterior and posterior anepisternum brown. Katepisternum with dorsal portion brown and ventral portion light brown, medial portion with ca. 10 setae, and postero-medial portion lighter than anterior portion. Anepimeron light brown with dorsal portion brown and antero-ventral margin lighter than medial portion. Metanepisternum and meron brown. Scutellum brown and setose without a delimitated row of setae. Mediotergite brown. Legs ( Fig. 1A View Figure 1 ) uniformly brown with lengths of (n= 1): fore leg [femur (1.8 mm), tibia (1.8 mm), tarsus (2.8 mm)], mid leg [femur (2.2 mm), tibia (2.1 mm), tarsus (3 mm)], and hind leg [femur (1.9 mm), tibia (2.3 mm), tarsus (3.3 mm)]. Fore and hind coxae slightly lighter than mid coxa; Coxae with setae anterolaterally. Tibiae with apical spur, hind tibia spur curved and twice as long as fore and mid tibiae spurs. Hind tibia strongly swollen apically with distinct patch of setae. Claws non-pectinate with basal combs. Basal comb of claws with two ventral tines.Wing ( Fig. 1E View Figure 1 ) (n= 1; length: 3.9 mm; width: 1.3 mm) with membrane hyaline. Wing veins brown and setose. Vein Sc ends basally to Rs origin. Vein R 2+3 curved, branched and with the origin subtly apical to crossvein r-m origin. Vein M 1+2 bifurcated; M bifurcation ends apical to R 2+3 branch origin. Crossvein m-m weak and near to the crossvein r-m terminus. False vein distinct and parallel to CuA, reaching ca. the basal 2/3 of CuA. Vein CuP ends apical to Rs origin. Length ratios R 2+3 /R 3 = 0.35, M 1+2 /M 2 = 1. Halter brown with light brown base. Abdomen ( Fig. 1D View Figure 1 ): uniformly light brown. Terminalia ( Figs. 2A–C View Figure 2 ): Spermatheca rounded and brown. Sternite VIII light brown, elongate (1.6x longer than wider), posterior portion dark brown with elongate setae, and concave. Tergite IX brown with posterior margin setose. Sternite IX light brown, single piece, medial portion tapered and slender (V-shaped) with undulating sides, lateral portion with anterior portion wider. Segment X dark brown, single piece, very elongate (extending beyond apical portion of cercus), lateral margin with many elongate setae, and medial cleft projecting to subapical portion (junction point between the parts). Cercus dark brown, elongate, apical portion rounded with elongate setae.

Male redescription. ( Figs.3A–B View Figure 3 ). Terminalia: Tergite X with distinct lateral projection extending from basal portion of central plate (dorsal view) to sides. Parameres L-shaped (lateral view) and projecting laterally. Aedeagus like a stripe reaching approximately medial portion of base of gonocoxite (dorsal view) and with median projection extending anteriorly, featuring small invagination; lateral portion with slight expansion at base. Gonocoxal apodeme tapered, projecting anteriorly, and curving towards medial portion. This redescription of the male terminalia is meant to be complementary to the original description ( Chaverri & Borkent, 2007). For somatic structures, refer to the original description.

Material. 1♂ ( MNRJ#41280 View Materials ) and 1♀ ( MNRJ#41515 View Materials ) in slides. Peru, Cusco, Urubamba, Machu Picchu, Quebrada Chachabamba , S13°11’18.8” W72°30’38”, 2240 m, 22/V/2021, hand net, AVG Falcón & KRM Castro col. ( Figs. 1G–H View Figure 1 ) GoogleMaps .

Distribution. COSTA RICA, San José, Escazú, San Antonio (typelocality); Tarrazú, San Carlos. PERU, Cusco, Urubamba (new record) ( Fig.7).

Remarks. Dixella woodi was described based on two adult male specimens.This species differs significantly from other species recorded from Costa Rica due to characteristics of the katepisternum and male terminalia ( Chaverri & Borkent, 2007). The presence of setae on the katepisternum is a unique feature among neotropical species ofDixella. The shape and arrangement of setae of the gonocoxite of D. woodi distinguishes it from other Dixella species ( Chaverri & Borkent, 2007), which typically have an apical lobe with an expanded apex, as seen in D. maculata Chaverri & Borkent, 2007 , D. hernandezi Chaverri & Borkent, 2007 , and D. suzukii Chaverri & Borkent, 2007 . Dixella maculata has a wing with a brown spot over the crossvein r-m and an apical lobe with two apical setae. Dixella hernandezi has numerous small spicules and a bilobed apex of the apical lobe. Dixella suzukii has two elongated setae at the base of the apical lobe, and the base of the gonostylus is widened, tapering towards the apex.

The female of D. woodi is very distinct from the other females of Dixella species recorded for the Neotropical region. Few species of Dixidae have females known and/or described in detail, especially in the Neotropical region. Only 11 species have females described in detail that assists for comparison, namely: Dixella atitla Huerta & Ibáñez-Bernal, 2021 , Dixella lobata Chaverri & Borkent, 2007 , Dixella machiotla Huerta & Ibáñez-Bernal, 2023 , D. maculata , Dixella moultoni Corrêa, Scarpa, Pinho & Gil-Azevedo, 2024 , Dixella scitula Belkin, Heinemann & Page, 1970 , Dixella shannoni ( Lane, 1942) , Dixella spinosa Corrêa, Scarpa, Pinho & Gil-Azevedo, 2024 , D. suzukii , Dixella venezuelensis ( Lane, 1942) , and Mesodixa biambulacra Belkin, Heinemann & Page, 1970 ( Lane, 1942, 1953; Belkin et al., 1970; Chaverri & Borkent, 2007; Huerta & Ibáñez-Bernal, 2021, 2023; Corrêa et al., 2024). The female of D. woodi can be distinguished from the other species (mentioned above) by the length of segment X, which extends beyond the apical portion of the cercus, while the other species has the length of segment X equal or shorter than the length of the cercus.

Chaverri & Borkent (2007) warned about one female specimen collected in Colombia (Cundinamarca, Finca Bella Vista) that could be a female of D. woodi , but due to that distance from the type locality ( Costa Rica), they preferred not to designate it as the female ofD. woodi . We believe that this material could be a female of D. woodi , but we did not observe it in this study.

Chaverri & Borkent (2007) described the male of D. woodi and made the following comment: “Parameres, aedeagus not identified with certainty”. Some structures of the male terminalia can be challenging to visualize when fixed on slides. We described and redescribed some of these structures that were not clearly visualized, and emphasized others that were observed in the analyzed specimen, such as paramere, aedeagus, tergite X, and gonocoxal apodeme. The remaining structures in the description of D. woodi by Chaverri & Borkent (2007) are as described in the original description.