Phytobia dalensi Boucher, 2025

Phytobia dalensi Boucher , n. sp.

( Figs 14 View FIG ; 15 View FIG )

urn:lsid:zoobank.org:act:71404E3D-F260-4C95-BD87-57AF6FDEA619

TYPE MATERIAL. — Holotype. Guyane • ♂; Mitaraka , sampling site: MIT-E-savane roche 2; 02°13’59.8”N, 54°27’46.5”W; 471 m; open/ partially opened areas; 13-20.VIII.2015; MT (6 m); Pierre-Henri Dalens leg.; sample code: MITARAKA/230 , sorted by M. Pollet; MNHN. GoogleMaps

ETYMOLOGY. — The species name is a patronym in honour of Pierre-Henri Dalens, president of the Société entomologique Antilles-Guyane (SEAG) who participated to phases two and three of the expedition and collected most of the Agromyzidae of Mitaraka with a 6 m long Malaise trap on one of the savane roches.

DIAGNOSIS. — This species differs from all other Neotropical species of Phytobia by the combination of the following characters: wing hyaline; 3+ 0 dc with anterior postsutural dc strongly reduced; frons yellowish brown; anepisternum completely brown; mesonotum mostly black, with posterolateral corner narrowly yellow; femora yellow, with mid and hind femur narrowly brown apically; abdomen mostly yellow with black spots centrally and laterally on hind tergites; male distiphallus consisting of two tubules that are approximately 1.5 × length of mesophallus.

DISTRIBUTION. — French Guiana.

HOST. — Unknown.

DESCRIPTION

Male

Orbital plate not projecting in front of eye in profile; frons width including orbital plates 0.35 mm at midpoint; orbital plate 0.2 × width of frons at midpoint; lunule small, collapsed inside; ocellar triangle extended anteriorly to level of anterior ors; two reclinate ors and two ori: upper ori reclinate or lateroclinate and lower ori inclinate ( Fig. 14B View FIG ); orbital setulae reclinate, in one row, except for 1-2 extra setulae; first flagellomere small, rounded apically with short pubescence; arista long with distinct pubescence; gena narrow, at midpoint about 0.05 × maximum eye height ( Fig. 14B View FIG ); clypeus medium width, with upper margin rounded; small epistoma present ( Fig. 14D View FIG ); 3+ 0 dc with only two posterior ones well-developed ( Fig. 14F View FIG ), anterior postsutural dc reduced, about 0.33 × length of second dc; prsc present; acrostichal setulae numerous, in about 8-9 rows; mid tibia with two posterolateral setae; wing length approximately 2.2 mm (wing slightly bent); last section of M 4 0.6 × length of penultimate section; vein R 4+5 ending close to wing tip; distal margin of R 1 expanded near junction ( Fig. 14E View FIG ).

Colour

Frons mat, yellowish-brown ( Fig. 14C View FIG ); orbital plate and ocellar triangle subshining, darker brown except for orbital plate yellowish at level of ori and below; antennae yellowish, first flagellomere slightly infuscated with brown ( Figs 14B, D View FIG ); clypeus and palp yellowish brown; face yellowish ( Fig. 14D View FIG ); mesonotum shiny brown, with the posterolateral corner possibly narrowly yellow (difficult to see due to the collapsed thorax) ( Fig. 14F View FIG ); scutellum brown; postpronotum yellow with small brown spot; notopleuron yellow; other pleura completely brown; fore leg including coxa and trochanter yellow, tarsi slightly darker yellowish brown; mid and hind femora yellow with apex narrowly brown ( Fig. 14A View FIG ); mid coxa brownish; mid and hind tibia and tarsi brown; halter yellow; calypter and margin yellow; fringe brown. Abdomen yellow with dark brown spots medially on tergites 3-6 in addition to lateral brown spots on tergites 5-6 similar to P. corona Boucher , n. sp. ( Fig. 12F View FIG ).

Male genitalia

Distiphallus ( Fig. 15B View FIG , arrow a) separated into two tubules ( Fig. 15A View FIG ) that are approximately 1.5 × longer than mesophallus ( Fig. 15B View FIG , arrow b); hypandrium without distal apodeme, conspicuously constricted near midpoint ( Fig. 15C View FIG ); surstylus, typical of the Phytobia unica group (see above), with multiple spines ( Fig. 15D View FIG ); ejaculatory apodeme with short stalk and medium size blade ( Fig. 15E View FIG ).

REMARKS

This new species belongs to the Phytobia unica group ( Boucher 2010) and is externally most similar to P. mentula Sasakawa, 1992 described from Peru ( Sasakawa 1992a). The male phallus of these two species, however, is distinctly different. Phytobia dalensi Boucher , n. sp., was previously identified as morphospecies Phytobia Mit- 4 in Boucher & Pollet (2021).