Bactrocera (Bactrocera) adamantea Leblanc & Doorenweerd

Leblanc, Luc, Doorenweerd, Camiel, Jose, Michael San, Pham, Hong Thai & Rubinoff, Daniel, 2018, Descriptions of four new species of Bactrocera and new country records highlight the high biodiversity of fruit flies in Vietnam (Diptera, Tephritidae, Dacinae), ZooKeys 797, pp. 87-115 : 103-106

Bactrocera (Bactrocera) adamantea Leblanc & Doorenweerd sp. n.

Holotype.

Male. Labelled: "Vietnam: Lâm Đ ồng Province, Cát Tiên National Park, Ranger station Road, 11.4485N, 107.4416E, 16-18-x-2015, M. San Jose and D. Rubinoff, FF581, Zingerone trap. Molecular voucher ms6092". Deposited in UHIM. Paratypes: 3 males. Vietnam, Lâm Đ ồng Province, Cát Tiên National Park, 16-18-x-2015, at the following sites, identified by their geographical coordinates: 11.4539N, 107.4430E, (1 pinned, molecular voucher ms6093), 11.4485N, 107.4416E, (1 pinned, molecular voucher ms6236), 11.4472N, 107.4392E, (1 in ethanol). All specimens collected by Michael San Jose and Daniel Rubinoff, in zingerone-baited traps. One paratype deposited in UHIM, one in WFBM and one in VNMN.

Differential diagnosis.

Bactrocera adamantea belongs to the (polyphagous) B. dorsalis complex of notoriously difficult to identify species ( Leblanc et al. 2015c), defined by having a mostly dark scutum, a costal band that does not expand apically, and a black T shaped pattern on the abdomen. It can easily be differentiated from all congeners however by the yellow diamond shaped medial vitta on the scutum (Figure 12B).

Molecular diagnostics.

Bactrocera adamantea is easily distinguished from all other Bactrocera using either section of COI. The closest species is B. nigrita , with a minimum intraspecific pairwise distance of 7.82 % in 1,496 bp of COI [8.66 % in COI5P, 7.18 % in COI3P] (Figure 11).

Description of adult.

Head (Figure 12A). Vertical length 1.66 ± 0.09 (SE) (1.55-1.73) mm. Frons, of even width, length 1.38 ± 0.02 (1.36-1.40) times as long as broad; fulvous with light fuscous (may be absent) around orbital setae and on anteromedial hump; latter covered by short red–brown hairs; orbital setae dark fuscous: one pair of superior and two pairs of inferior fronto-orbital setae present; lunule yellow. Ocellar triangle black. Vertex light fuscous. Face fulvous with medium sized oval black spots in each antennal furrow; length 0.58 ± 0.04 (0.55-0.63) mm. Genae fulvous, with fuscous sub-ocular spot; red–brown seta present. Occiput fulvous to light fuscous and yellow along eye margins; occipital row with 6-8 dark setae. Antennae with segments 1 (scape) and 2 (pedicel) fulvous and segment 3 (first flagellomere) fulvous with fuscous outer surface; a strong fulvous dorsal seta on segment 2; arista black (fulvous basally); length of segments: 0.23 ± 0.01 (0.23-0.25) mm; 0.28 ± 0.03 (0.25-0.30) mm; 0.82 ± 0.01 (0.80-0.83) mm.

Thorax (Fig. 12B, F). Scutum black except red–brown as two parallel bands running from anterior margin to mid-length and as markings around notopleural suture and medial to postpronotal lobes. Pleural areas black except red–brown proepisternum and anterior portion of anepisternum below postpronotal lobes. Yellow markings as follows: postpronotal lobes; notopleura (notopleural callus); broad mesopleural (anepisternal) stripe, reaching level of anterior notopleural seta dorsally, continuing to katepisternum as a transverse spot, anterior margin slightly convex; anatergite (posterior apex black); anterior 80 % of katatergite (remainder black); two broad parallel-sided lateral postsutural vittae ending at level of intra-alar setae; large diamond-shaped medial marking on posterior end of scutum. Postnotum red–brown medially and black laterally. Scutellum yellow except for narrow black basal band. Setae (number of pairs): 1 scutellar; 1 prescutellar; 1 intra-alar; 1 posterior supra-alar; 1 anterior supra-alar; 1 mesopleural; 2 notopleural; 4 scapular; all setae well developed and red–brown.

Legs (Figure 12F). Femora fulvous, except for small fuscous subapical spot on outer surface of fore femur; tibiae dark fuscous; mid-tibiae each with an apical black spur; tarsi fulvous.

Wings (Figure 12E). Length 5.78 ± 0.11 (5.67-5.89) mm; basal costal (bc) and costal (c) cells colorless; microtrichia in outer corner of cell c only; remainder of wings colorless except fuscous subcostal cell, moderately broad fuscous costal band overlapping with R2+3 and widening slightly as it crosses apex of R2+3 to end between extremities of R4+5 and M, a narrow fuscous anal streak ending at apex of posterior cubital cell; dense aggregation of microtrichia around A1 + CuA2; supernumerary lobe of medium development.

Abdomen (Figure 12C, D, F). Elongate oval; terga free; pecten present on tergum III; posterior lobe of surstylus short; abdominal sternum V with a deep concavity on posterior margin. Tergum I and sterna I and II wider than long. Tergum I fulvous with dark fuscous along base medially and black along lateral margins; tergum II fulvous except for a narrow transverse black band across anterior margin which extends to cover narrow lateral margins. Terga III–V orange–brown with a dark T-shaped pattern consisting of a broad transverse black band across anterior margin of tergum III expanding broadly over lateral margins and a broad medial longitudinal black band over all three terga, broad black lateral markings on tergum IV and narrowly black along lateral margins of tergum V. A pair of dark fuscous ceromata (shining spots) on tergum V. Abdominal sterna dark fuscous except for fulvous sternite II.

Etymology. The name adamantea is an adjective that refers to the diamond-shaped marking on the scutum, uniquely distinctive to this species.

Notes. It was referred to as Bactrocera species 69, sister to B. (Bactrocera) fuscitibia Drew and Hancock, in the phylogeny presented in San Jose et al. (2018). It keys as far as couplet 80, page 240, in Drew and Romig (2016), and differs from B. lateritaenia by the presence of the conspicuous diamond-shaped marking on the scutum (Figure 12B), which is also uniquely distinctive among Dacine fruit flies.