Anastrepha korytkowskii Norrbom, 2015

Rodriguez, Erick J., Steck, Gary J., Moore, Matthew R., Norrbom, Allen L., Diaz, Jessica, Somma, Louis A., Ruiz-Arce, Raul, Sutton, Bruce D., Nolazco, Norma, Muller, Alies & Branham, Marc A., 2022, Exceptional larval morphology of nine species of the Anastrepha mucronota species group (Diptera, Tephritidae), ZooKeys 1127, pp. 155-215 : 155

Anastrepha korytkowskii Norrbom, 2015

Figs 53-57 , 58-63 , 64-65

Material examined.

Peru • 2 larvae; Madre de Dios, Puerto Maldonado, Centro de Investigación y Capacitación Rio Los Amigos (CICRA), trail 21; 12.5721°S, 70.0889°W; 232 m a.s.l.; 17 Apr. 2016; N. Zenteno leg.; reared from fruit of Quararibea wittii ; FSCA (AP20180315.02- AP20180315.03) • 7 larvae; same, trail 11; 12.5636°S, 70.0847°W; 250 m a.s.l.; 4 Dec. 2015; R. Bustamante leg.; reared from fruit of Quararibea wittii ; FSCA (AP20180315.01, AP20180315.04, AP20180315.05, AP20180321.03, AP20180321.04, AP20180329.01, AP20180329.05) • 2 larvae; same, trail 21; 12.5708°S, 70.0847°W; 224 m a.s.l.; 2 Dec. 2015; R. Bustamante leg.; reared from fruit of Quararibea wittii ; FSCA (AP20180315.07, AP20180516.13) • 8 larvae; same, trail 21; 12.5721°S, 70.0889°W; 232 m a.s.l.; 14-21 Mar. 2016; N. Zenteno leg.; reared from fruit of Quararibea wittii ; FSCA (AP20180315.08, AP20180315.09, AP20180329.06, AP20180329.07, AP20180329.09-AP20180329.12).

Diagnosis.

The larvae of A. korytkowskii can be distinguished from those of other species of Anastrepha by its peculiar short preoral lobe medial to the lobe bearing the preoral organ, fringed posterior margins of the accessory plates, posterior margins of the oral ridges (2-5 anterior ridges dentate, medial and posterior ridges entire), and 3-5 comb-like processes adjacent to the labium and posterior to the oral ridges. The posterior margins of the accessory plates resemble those of A. crebra , A. haplacantha , A. nolazcoae , Anastrepha sp. Peru-82, Anastrepha sp. nr. protuberans , and Anastrepha sp. Sur-16, although in A. korytkowskii the posterior margins of the oral ridges are distinct (as shown above). Anastrepha korytkowskii further differs from the latter six species by the number of oral ridges, ventral surface of mouthhook, number of tubules and distal width of the prothoracic spiracle, and basal width of the posterior spiracle (see Tables 2 - 4 ).

Description.

Habitus. Third instar elongate, cylindrical, tapered anteriorly and caudal end truncate; color creamy; amphipneustic. Length 6.10-8.54 mm and width 0.93-1.57 mm at the sixth abdominal segment.

Pseudocephalon (Figs 53-56 ). Antenna and maxillary palp on moderately developed lobe. Antenna with cylindrical base and apical knob. Maxillary palp bearing three papilla sensilla, two knob sensilla; dorsolateral group of sensilla bearing two well-developed papilla sensilla, aligned perpendicular to palp and surrounded by a collar. Facial mask partly globular in lateral view, upper right section lacking ridges and accessory plates and forming almost a right angle. Preoral organ bearing one unbranched peg sensillum, located apically on small, elongate-rounded lobe directly anterior to mouthhook; adjacent medial preoral lobe separate, slightly smaller and irregularly rounded. Oral ridges in 12-14 rows, margins of anterior 2-5 ridges irregularly dentate, margins of medial and posterior ridges entire (some sparsely notched); 3-5 comb-like processes adjacent to labium and posterior to oral ridges; 14-20 accessory plates in one series, but absent adjacent to the anterior five or six oral ridges, covering a much smaller area than oral ridges, with fringed posterior margins. Labium triangular, anterior surface knobby, ventrally with two visible sensilla.

Cephaloskeleton (Figs 57 - 59 ). Total length from tip of mouthhook to end of ventral cornu 0.76-0.86 mm. Mouthhook well sclerotized, black apically and basally; length a 0.16-0.18 mm; length b 0.10-0.13 mm; height c 0.11-0.13 mm; ratio a:b 1.4-1.6; ratio a:c 1.4-1.5. Tooth long, sharp, strongly curved, concave ventrally, ventral surface eroded. Intermediate sclerite 0.15-0.17 mm long, 0.13-0.14 mm wide at ventral bridge. Epipharyngeal sclerite visible only in dorsal view, with medial lobe directed anteriorly. Labial sclerite robust, sclerotized, and triangular in dorsal view. Parastomal bar extending for almost entire length of intermediate sclerite. Dorsal arch 0.19-0.21 mm high. Dorsal cornu with well-defined sclerotized area adjacent to notch, 0.36-0.46 mm long. Dorsal bridge prominently projecting anteriorly from dorsal cornu and slightly sclerotized. Anterior sclerite irregularly shaped and sclerotized. Cornu notch (N) 0.24-0.29 mm long and cornu notch index (N/DC) 0.6-0.7. Ventral cornu sclerotized between notch and pharyngeal bar and grooves. Pharyngeal filter with weakly sclerotized anterior bar and 7-9 ridges forming a series of grooves along length of ventral cornu. Ventral cornu 0.39-0.55 mm long from pharyngeal bar to posterior end of grooves. Ventral cornu 1.2-1.4 × as long as sclerotized area of dorsal cornu.

Thoracic and abdominal segments. Thoracic segments with dorsal spinules conical, symmetrical to slightly curved posteriorly; dorsal spinule pattern as follows: T1 with six or seven rows, forming scalloped plates; T2 with 2-5 rows; T3 lacking spinules; ventral spinule pattern as follows: T1 with 8-12 rows; T2 with three rows; T3 lacking spinules. Abdominal segments (A1-A8) lacking dorsal spinules; ventral creeping welts present on all abdominal segments (A1-A8); ventral spinule pattern as follows: A1 with one or two rows; A2 with six or seven rows; A3 with seven or eight rows; A4 with seven or eight rows; A5 with 6-8 rows; A6 with eight rows; A7 with 6-8 rows; A8 with 6-8 rows. Additional 2-4 irregular rows of spinules anteriorly and posteriorly to anal lobes, spinules large, conical, pointing away from anal lobes.

Prothoracic spiracle (Figs 60 , 61 ). Bilobed, bearing 12-18 tubules, distally rounded and arranged in a single sinuous row. Spiracle distal width 0.19-0.24 mm; basal width 0.07-0.10 mm at junction with trachea.

Caudal segment (Figs 62 , 63 ). Dorsal (D1 and D2), intermediate (I1 and I2), lateral (L1), and ventral (V1 and V2) tubercles and sensilla weakly developed; D1 distinctly anterior to D2. Intermediate tubercles I1 and I2 more strongly developed, but associated sensilla weakly developed; I1 lateral and sometimes slightly ventral to I2. Lateral (L1) and ventral (V1 and V2) tubercles and associated sensilla weakly developed. Anal lobe entire and very protuberant.

Posterior spiracle (Figs 62 , 64 , 65 ). Located above horizontal midline. Posterior spiracle openings with thick rimae and numerous trabeculae; 56-77 µm long; 20-24 µm wide; ratio length/width 2.8-3.2. Ecdysial scar apparent. Felt chamber oval, 124-148 µm in diameter at junction with trachea. Spiracular process SP-I comprising 9-15 trunks and 21-33 tips; ratio tips/trunks 2.2- 2.3; basal width 14-28 µm; ratio basal width/length of spiracular opening 0.24-0.47. SP-II comprising 4-7 trunks and 9-17 tips. SP-III comprising 5-10 trunks and 12-19 tips. SP-IV comprising 8-15 trunks and 17-31 tips; ratio tips/trunks 2.0-2.1; basal width 12-21 µm; ratio basal width/length of spiracular opening 0.21-0.30.

Distribution.

Anastrepha korytkowskii is known only from Bolivia (La Paz and Santa Cruz) and eastern Peru (Cusco, Huánuco, Junín, and Madre de Dios).

Biology.

We reared this species from fruit of Quararibea wittii , the only known host plant ( Norrbom et al. 2015). The larvae feed only on the pulp of the fruit.

Molecular identification.

COI barcodes were generated from 19 larvae and two adults and submitted to GenBank (MT654705-MT654725). These data further confirm the identity of the described larvae. K2P distances between A. korytkowskii larvae and the three adult sequences (MT654712, MT654722, KY428387) ranged from 0.0-2.1%. BLAST searches were consistent with our new data, yielding only one good match: A. korytkowskii (97.77-99.04% sequence identity; KY428387). Additionally, all 19 larval barcodes returned consensus identifications of A. korytkowskii with three votes ( Moore et al. in press).

Figures

Figures 53 - 57. Scanning electron photomicrographs of third instar of Anastrepha korytkowskii 53 pseudocephalon 54 oral ridges 55 antenna and maxillary palp 56 preoral organ 57 ventral surface of mouthhook. Abbreviations: CLP, comb-like processes. Scale bars: 10 μm (55 - 57); 20 μm (54); 50 μm (53).

Figures 58 - 63. Optical photomicrographs and scanning electron photomicrographs of third instar of Anastrepha korytkowskii 58 cephaloskeleton, lateral view 59 cephaloskeleton, dorsal view 60 prothoracic spiracle, lateral view 61 prothoracic spiracle, dorsolateral view 62 caudal segment 63 anal lobe. Abbreviations: ES, epipharyngeal sclerite; LS, labial sclerite. Scale bars: 50 μm (60, 61); 100 μm (63); 200 μm (58, 59, 62).

Figures 64, 65. Scanning electron photomicrograph and optical photomicrograph of posterior spiracles of third instar of Anastrepha korytkowskii. Scale bars: 50 μm (64, 65).