Bactrocera (Bactrocera) youngi, Korneyev & Leblanc & Hauser & General & Gaimari, 2024

Korneyev, Severyn V., Leblanc, Luc, Hauser, Martin, General, David E. M. & Gaimari, Stephen D., 2024, Descriptions of two new species of Bactrocera Macquart (Diptera: Tephritidae: Dacinae: Dacini) from the Philippines with distinct orange medial stripes on the scutum, Zootaxa 5432 (4), pp. 573-599 : 576-578

Bactrocera (Bactrocera) youngi new species

( Fig. 31 a–g )

Type material: 49 specimens.

Holotype. ♂ Philippines: Luzon, Camarines Sur, Mt. Isarog Natural Park, station at base ; 13.66330 N, 123.33579 E, 600 m, 30.x.2019, cue-lure trap, (A.D. Young, N. Ellenrieder) ( CSCA19L1356 ) | DNA Voucher 21N 111, Tephritidae, Det. Apr. 2021 . (Deposited at PNM).

Paratypes: 30♂. Same location and date as holotype ( CSCA19L1356 ) ; 2 paratypes deposited at UPLB ; 2 paratypes deposited at BPIM ; 2 paratypes deposited at USNM ; 2 paratypes deposited at BPBM ; 2 at BME, 2 at WFBM , 18 paratypes deposited at CSCA .

8♂ same location and date as holotype, hand netted (A.D. Young, N. Ellenrieder) ( CSCA19L1358 ) ( CSCA) ;

9♂ same location, Park entrance ; 13.66286 N, 123.33399 E, 600 m; 30.x.2019, cue-lure trap (A.D. Young, N. Ellenrieder) ( CSCA19L1360 ) ( CSCA) ;

1♂ same location, Naga, Carolina, Peñafrancia Resort , near rooms, 13.66445 N, 123.28207 E, 300 m, 1– 4.xi.2019, cue-lure trap (A.D. Young, N. Ellenrieder) ( CSCA19L1369 ). ( CSCA) .

Differential diagnosis. Bactrocera youngi belongs to the B. dorsalis complex, defined by having a mostly dark scutum, a costal band that does not expand apically (slightly broader in B. youngi than in most similar species), and a black T-shaped pattern on the abdomen. The new species can easily be differentiated from all other species by the following combination of characters: facial spots narrow, elongate ( Fig. 31c ), scutum mostly black except two distinct submedial orange stripes and postsutural lateral yellow vittae, some specimens with an orange postmedial spot ( Fig. 31a , 3 ), subscutellum entirely black ( Fig. 31d ), and abdomen with shining black T-shaped pattern and distinct broad black margins ( Fig. 31d ). This species differs from B. ellenriederae by the predominantly black color of the scutum, black subscutellum, shining black pattern on the abdomen, and shorter surstylus.

Description of adult. Head. Height 1.4 ± 0.2 (SE) (1.2–1.6) mm. Frons yellow with light brown area (sometimes absent) around orbital setae and on anteromedial hump, latter covered by short reddish-brown setulae; orbital setae dark brown: one pair of superior and two pairs of inferior fronto-orbital setae present; lunule yellow Ocellar triangle black. Vertex light brown. Face yellow with medium sized oval black spots in each antennal furrow; facial spots 0.26 ± 0.04 (0.22–0.30) mm long and 0.12 mm ± 0.02 (0.10–0.14) mm wide. Gena yellow, with brown sub-ocular spot; reddish-brown seta present. Occiput ranging from black to dark brown, and yellow along eye margins; occipital row with 4–7 dark setae. Antenna with scape and pedicel yellow and first flagellomere yellow with brown lateral surface; a strong yellow dorsal seta on pedicel; arista black, yellow basally.

Thorax. Scutum black except yellow areas (see below) and two parallel submedial orange stripes running from anterior margin to level of wing base. Pleuron black except yellow areas and dark orange proepisternum and anterior portion of anepisternum. Yellow (can be white in preserved specimens) markings as follows: postpronotal lobe; posterior 2/3 of notopleuron (notopleural callus); broad mesopleural (anepisternal) stripe, reaching level of anterior notopleural seta dorsally, continuing to katepisternum as transverse spot, anterior margin slightly convex; anatergite yellow (posterior margin black); anterior 80% of katatergite yellow (remainder black); sharply tapering lateral postsutural scutal vitta ending before level of intra-alar seta; orange spot present at base of prescutellar acrostichal setae in about 50% of specimens. Postnotum reddish-brown medially and black laterally. Scutellum yellow except for narrow black basal band. Subscutellum black. Mediotergite black with orange medially. Setae (number of pairs): 1 (apical) scutellar; 1 prescutellar acrostichal; 1 intra-alar; 1 posterior supra-alar; 1 anterior supra-alar; 1 mesopleural; 2 notopleural; 2 scapular; all setae well developed and reddish-brown.

Legs. Femora yellow; tibiae dark brown, mid-tibia with an apical black spur; tarsi dark brown.

Wing. Length 5.8 ± 0.5 mm; basal costal (bc) and costal (c) cells hyaline; microtrichia in apical corner of cell c only; remainder of wing colorless except moderately broad fuscous costal band covering all of subcostal cell and cell r 1, extending to about midpoint between apices of R 4+5 and M, extending narrowly beyond R 2+3 for most of its length, or at least to level of apex of vein R 1 and widening slightly as it crosses apex of R 2+3, to end between extremities of R 4+5 and M, and a narrow brown anal streak ending at apex of posterior cubital cell; dense aggregation of microtrichia around A 1 +CuA 2; supernumerary lobe moderately developed.

Abdomen. Elongate ovoid; pecten present on tergum III; posterior lobe of surstylus short; abdominal sternum V with deep concavity on posterior margin. Tergum I and sterna I and II wider than long. Tergum I yellow except dark brown to black basomedially and black along lateral margins; tergum II yellow except for narrow transverse black band across anterior margin which extends to cover narrow lateral margins. Terga III–V brownish-orange with well-developed shining black T-shaped pattern comprising broad lateral and medial black vittae over all three terga and band on anterior margin of tergum III. A pair of dark brown ceromata (shining spots) on tergum V. Abdominal sterna dark brown (almost black) except for yellow sternum II.

Male terminalia: Similar to Bactrocera limbifera ( Bezzi, 1919) ( David & Ramani, 2019) , a species not included in the key. Surstylus short, 0.2 mm long ( Figs. 31 f-g).

Female. Unknown.

Male attractant. Cue-lure.

Etymology. This species is named after dipterist Dr. Andrew Donovan Young, one of the collectors of the type series of this species.

Notes. This species keys as far as couplet 80 in Drew and Romig (2016, page 240), and differs from B. lateritaenia Drew and Hancock by the presence of distinct submedial orange vittae on the scutum, paired sharply tapering lateral postsutural yellow vittae ending before the level of the intra-alar setae, and the distinct black abdominal pattern. Its distinct species status is confirmed by COI sequences ( Fig. 34 ).

This species is very similar to B. ellenriederae new species, differs by the predominantly black color of the scutum, black subscutellum, the broader glossy shining black T-shaped pattern on the abdomen ( B. ellenriederae has matte brown T-shaped pattern), and the shorter surstylus.

Figures

FIGURE 3. (a–d) B. (G) continua (Bezzi, 1919)—(a) scutum and abdomen, dorsal view; (b) habitus, lateral view; (c) head, frontal view; (d) wing; (e) B. youngi sp. n—abdomen, dorsal view.

FIGURE 31. Bactrocera youngi sp. n.—(a) male, head and thorax, dorsal view; (b) male, habitus, left-side lateral view; (c) male, head, frontal view; (d), male, abdomen, dorsal view; (e) wing; (f) male, epandrium, lateral view; (g) male, epandrium, posterior view; (h) glans and preglans lobe of male phallus, lateral view.

FIGURE 34. Phylogram based on data from mitochondrial gene (COI) as recovered by Maximum Likelihood method using General Time Reversible model. Support values are recorded on each node maximum likelihood bootstrap percentages (BT = 300). B. sp3 = Undescribed species of Bactrocera near B. bivittata.