Phytobia piscivora Carvalho-Filho, Monteiro & De-Souza, 2025

Phytobia piscivora Carvalho-Filho, Monteiro & De-Souza , sp. nov.

( Figs 4 View FIGURE 4 , 6A–C View FIGURE 6 , 7 View FIGURE 7 )

Type material. HOLOTYPE ♂ ( MPEG): Brasil [ Brazil], TO [state of Tocantins], Pium / Base [= Research Center] Canguçu / 12 a [to] 21.V.2016 / F. S. Carvalho-Filho [collector] / Busca ativa.

PARATYPES. 2 ♂♂ ( MPEG): same data as holotype .

Description. Male. Body length 2.2–2.3 mm; wing length 2.0– 2.1 mm.

Female. Unknown.

Colouration. Head ( Fig. 4A View FIGURE 4 ): Frons matte black with grey microtomentum; fronto-orbital plate and ocellar triangle black with grey microtomentum; lunule with silvery microtomentum; face greyish-black; clypeus shining black; gena dark brown with grey microtomentum; antenna including the arista entirely brown; palpus brown; proboscis brownish-yellow; labellum brownish-yellow, with light setae. Thorax ( Fig. 4A–4B View FIGURE 4 ) scutum mostly black, with narrow yellow area laterally and posteriorly, and with a large yellow area between dorsocentrals to level of second seta, black spot of scutum constricted at level of transverse suture, light brown postalar spot present; scutellum light yellow; postpronotum light yellow, with brownish spot on anterior and lower margins; notopleuron and anepimeron light yellow; anepisternum light yellow, with small brown spot on basal half; katepimeron dark brown, katepisternum dark brown with upper posterolateral corner yellow; meron brown; halter entirely yellow; calypter light yellow, with margin and fringe brown. Wing ( Fig. 4A View FIGURE 4 ): clear, light yellow at base; legs brown with apex of all femora yellow. Abdomen ( Fig. 4C View FIGURE 4 ): mostly yellow, tergites 5 and 6 with median brown stripe touching at limit of tergites; terminalia entirely dark brown.

Head. Frons not visible above eye margin in lateral profile; 2 reclinate upper frontal setae and 2 inwardly inclinate lower frontal setae, similar in size; orbital setulae erect in one row; ocellar triangle short, ending before second upper frontal seta; lunule high, 18% of frons length; clypeus rounded; first flagellomere circular; arista very long, more than 2/3 of vertical height of eye, short pubescent; vibrissa short and thick, measuring about 1/3 of aristal length.

Thorax ( Fig. 4B View FIGURE 4 ). Acrostichal setulae arranged in ten irregular rows; prescutellar seta absent; 3+1 dorsocentral setae, increasing in size from presutural; 2 notopleural setae, similar in size. Wing ( Fig. 4A View FIGURE 4 ). Wing tip nearer to R 4+5 than to M 1; R 4+5 and M 1 slightly recurved; C sections 2–4: 0.46: 0.16: 0.13; ultimate section of CuA 1 as long as basal section; r-m at midpoint of dm. Legs. Fore tibia without posterodorsal seta; mid tibia with 1 posterodorsal seta on middle third.

Terminalia ( Figs 6A–C View FIGURE 6 ). Epandrium about as high as long, with many thick and short setae mainly on posterior margin and with some spines along ventral margin; cercus more than 2/3 height of epandrium, tapering distally, covered with thick and short setae and with 2 distinct setae at apex; surstylus almost rounded, with posterior margin bearing prominent pointed projections and with some scattered setae; hypandrium U-shaped; phallapodeme long, about 2.5 times length of hypandrium; basiphallus long and narrow, with many cuticular spines in membrane on distal half; mesophallus ovate in lateral view, and with a median constriction in ventral view; distiphallus rounded in lateral view and widened with bilobed apex in ventral view; ejaculatory apodeme broad, with widest basal part about ⅓ as wide ( Fig. 6C View FIGURE 6 ).

Distribution. Brazil (Tocantins) ( Fig. 7 View FIGURE 7 ).

Etymology. The specific name “ piscivora ” is derived from the Latin piscis, meaning “fish”, plus vorō, meaning “to devour”, alluding to the feeding behavior of adult flies that were found feeding on a dead fish.

Natural history. Adult specimens of Phytobia piscivora sp. nov., P. pium sp. nov. and P. pluviasilvae were found feeding on dead fish at the margin of a large river (Araguaia River). Other species of Agromyzidae of the genera Agromyza Fallén and Phytomyza Fallén have been recorded visiting vertebrate carcasses in the Old World ( Černý 2018; Sawaby et al. 2018), indicating that this is a widespread behavior in the family. Carcasses of vertebrates may represent a source of minerals and proteins that they cannot obtain in required amounts from their host plant, as observed in other species of insects ( Petit et al. 2019).

Remarks. In the last published key to the Neotropical species of Phytobia ( Sousa & Couri 2017) , the new species runs to P. spinifera Sousa & Couri , from which it differs in having a scutum with a light brown postalar spot, the epandrium has conspicuous spines, the cercus tapers distally, and the distiphallus is apically bilobed in ventral view and without distal spines.

The phallus of P. piscivora sp. nov. is similar to that of P. amazonica Sousa & Couri in having a mesophallus and distiphallus that appear rounded in lateral view, and the mesophallus has a pair of black markings in ventral view ( Figs. 6D–E View FIGURE 6 ; 36 and 37 in Sousa & Couri (2017)). It differs from P. amazonica mainly in scutal colour, in that it has only one elongate stripe posterolaterally on the black scutal marking, and in having a light brown postalar spot. In P. amazonica , there are two elongate stripes on the scutal spot and the postalar region is entirely yellow.