Drosophila (Sophophora) anomalata, McEvey & Schiffer, 2015

McEvey, Shane & Schiffer, Michele, 2015, New Species in the Drosophila ananassae Subgroup from Northern Australia, New Guinea and the South Pacific (Diptera: Drosophilidae), with Historical Overview, Records of the Australian Museum 67 (5), pp. 129-161 : 142-143

Drosophila (Sophophora) anomalata sp.nov.

Figs. 50–52 , 72–81 , 91 , 93

Types. Holotype ♂, AMS K357034 , Schiffer 51016, “[ Australia] QLD nr Deeragun 16km W of | Townsville, alt. 16 m | -19.2410° 146.6644°± 50m | F8 from iso- ♀ type culture | CHC221 establ. 16.iv.2014 | Michele Schiffer 21.xi.2014 ” . Paratypes (14♂♂, 5♀♀): K357032–033 ♂♂, K357035–046 ♂♂, K357047–051 ♀♀, all same data as holotype, also taken from the type culture 21.xi.2014, all in the Australian Museum. Type culture Schiffer CHC221 .

Distinguishing features. Sex combs of male forelegs developed on tarsomere I and II, usually only in 2 rows (rarely 3) on tarsomere I of 1–3 and 4–7 teeth, and in 2–3 rows on tarsomere II of 0–2, 2–4 and 3–4 teeth; female oviscapt darkly pigmented; males bob up and down vigorously in front of and facing females during courtship.

Description (♂)

Body length. 2.3 mm ♂.

Head. The colouration and shape of the head, the eyes and the front, together with the chaetotaxy resemble D. ananassae . Measurements of holotype ♂: BL(McE) mm = 2.35; BL(Z&T) mm = 1.63; hw/fw(ov) = 1.84; hw/fw(iv) = 2.31; hw/fw(vt) = 1.80; hw/fw(a.oc) = 2.00; hw/fw(a. r.orb ) = 2.09; hw/fw(x. r.orb ) = 2.05; hw/fw(ptl) = 2.40; fw(ov)/ fl = 1.53; fw(iv)/fl = 1.22; fw(vt)/fl = 1.56; fw(a.oc)/fl = 1.41; fw(a. r.orb )/fl = 1.38; fw(vt)/fw(ptl) = 1.33; p. r.orb = 1.01; rc.orb = 0.39; proc.orb/a. r.orb = 2.57; oc/proc.orb = 1.04; pv/oc = 0.75; p. r.orb /iv = 0.70; orbito-index = 0.63; vt-index = 1.10; oc-gap/pv-gap = 0.50; o/j = 14.13; ch/o = 0.09; o/ow = 1.22; svb/vb = 0.78; flw = 1.32; avd = 0.89; adf = 1.70. Arista with 4–5 dorsal rays and 3–4 ventral rays plus a terminal fork; c.11 free ends.

Thorax. Acrostichal hairs in 8 rows in front of dorsocentral bristles, 4–6 rows between dorsocentrals. Ratio anterior/ posterior dorsocentrals 0.6. Preapical bristles on all tibiae; apicals on first and second tibiae. Sex comb of male foreleg ( Figs. 72–77 , Tables 1 and 2) developed on first two tarsal segments, usually only in 2 rows (rarely 3) on tarsomere I of 1–3 and 4–7 teeth, and in 2–3 rows on tarsomere II of 0–2, 2–4 and 3–4 teeth. The average total number of teeth in all sex combs on one leg is 14.5 (range 12–20, Table2). Other thoracic measurements of holotype: bsc/asc = 0.87; sternoindex = 0.53; m/a.kepst = 0.59; p.kepst/pdc = 1.07; pdc/asc = 0.90; asc–bsc/asc–asc = 1.18; a–pdc/dc-gap = 0.45; fw(a. oc)/dc-gap = 1.36.

Wing. Hyaline. Holotype (average, minimum–maximum): C-index = 1.68 (1.59, 1.42–1.70); 4v-index = 2.15 (2.22, 2.09–2.35); 4c-index = 1.47 (1.55, 1.43–1.66); 5x-index = 1.91 (1.96, 1.74–2.30); ac-index = 3.00 (3.13, 2.90–3.56); M-index = 0.74 (0.77, 0.74–0.84); prox.x = 0.72 (0.90, 0.68– 1.28); C3F = 0.52 (0.52, 0.49–0.54); L(Ax) = 1.95 (1.99, 1.91–2.07); WL = 1.66 mm (1.70, 1.64–1.78); L 1 = 1.61 mm (1.64, 1.58–1.73); width = 0.82 mm (0.84, 0.81–0.88).

Abdomen. Tergites of both sexes with diffuse, dark, narrow bands posteriorly, fainter posterolaterally.

Male terminalia. Epandrium (periphallic organs) ( Figs. 50–52 ). Genital arch narrow dorsally and broad laterally; toe (ventral epandrial lobe) elongate as in D. ananassae , with about 6–8 setae. Primary and secondary claspers present. Primary clasper (surstylus) large with an inner or median row of 4–5 strong setae that merge into a cluster of an additional 8–9 setae (one large) and two series of short, blunt, thick teeth (prensisetae) laterally. The upper series has c.5 prensisetae, the lower series has 3–4 of similar form. The secondary clasper (ventral cercal lobe) is very small with a very large curved, black, medial tooth, and with several small setae.

Hypandrium (phallic organs) ( Figs. 78–81 ). Anterior parameres small, digitiform with large apical seta and several medial sensilla and with a hugely expanded and recurved structure at its base—the basal extension (see bx in Fig. 4). The basal extension terminates as a long, pointed and sclerotized appendage; in ventral view, both sides (cf. lateral side only in D. pandora ), of this caudally extended structure are curved, similar to D. ananassae — basal extension tapers on both sides toward a pointed tip, e.g. Figs. 6, 8). The basal extension pivots outwards when the aedeagus extends. It is figured in the resting or notoutwardly-pivoted position in Figs. 78–81 . An acuminate kink in the “bend” of the anterior paramere (ak, Fig. 4) is absent as in D. ananassae (cf. present in D. pandora ). Posterior paramere long, extending beyond aedeagus; slender, tapering to a point, curving gradually not bending abruptly at apex of aedeagus and sheathing it. The overall “sheathed” phallus width is about 0.3 of the hypandrium width as in D. ananassae .

Female. Oviscapt darkly pigmented ( Fig. 91 , 93), otherwise difficult to correctly distinguish from D. ananassae , D. pallidosa , D. pandora etc., except by extrapolation from male siblings or progeny.

Distribution. Known only from four Queensland localities: Deeragun garden, Mango Tree Innisfail site CHE, Lake Placid [gardens and buildings], and Lake placid, rainforest remnant (see Appendix 1).

Etymology. The name for this species is a reference to the puzzling interrelationship of this species and the others of the ananassae complex in Australia. The morphological data, the hybridization data and the behavioural data are unexpected and anomalous.

Remarks

During the present study males from Deeragun garden, Mango Tree Innisfail site CHE and Lake Placid were found to have very weak sex combs, with a total number of teeth less than 20 ( Table 2), yet upon dissection, these males were found to have genitalia indistinguishable from D. ananassae . Drosophila ananassae and D. pandora have different male terminalia but slightly overlapping sex comb metrics, whereas D. ananassae and D. anomalata differ greatly in sex comb configuration but have similar terminalia. Several live cultures of D. anomalata were established from iso- ♀♀ collected at two of these three localities: Schiffer strain CHC221 from Deeragun garden, 9–11 Apr. 2014, and strains A5, A25, A29, A41, A43 and A209 from Lake Placid, 4–9 Nov. 2014. Females have distinctly blackened oviscapts compared to D. pandora , D. ananassae , D. ironensis , D. bipectinata , and D. pseudoananassae . There is a degree of infertility and unviability in crosses between D. pandora , D. anomalata and D. ananassae that cannot be attributed to Wolbachia ( Tables 3–5). Males of this species display a very distinctive bobbing behaviour while in front of and facing females during courtship. Spieth (1966:137) reported this exceptional behaviour, or one very similar, in strains from Popondetta (Texas 3021.3), Brown River (Texas 3020.9) and Queensland (Texas 2372.11, see comments above relating to this strain). Further work on the courtship behaviour of these species is clearly warranted and likely to be fruitful given recent advances in digital photography. Additionally, Crossley (1986) has found a range of song profiles made by males (with their wings) early and late in the courtship cycle in the ananassae subgroup . So courtship display and courtship song are likely to be insightful avenues for future investigation.

The combination of (a) morphological characters (sex combs and oviscapt), (b) differences in sexual behaviour and (c) negative heterosis after hybridization with related species, compel us to conclude that D. anomalata is yet another species that exists in the ananassae complex in northern Queensland. The possibility that this species is D. pallidosa is rejected because the blackened oviscapt would have been detected by Bock & Wheeler (1972) during their careful search for distinguishing traits among this complex of species. Furthermore, the Drosophila pallidosa strain k-aae002 (NAN24) from Lautoka, Fiji (Kyorin University stock) have females with pale, not blackened, oviscapts and 3 sex combs on tarsomere I of 2–3, 5, 5–6 teeth, and 3 combs on tarsomere II of 3, 4, and 4–5 teeth (23–26 teeth in total). The D. pallidosa stocks 14024-0433.00 and 14024-0433.01 (from the Drosophila Species Stock Center, San Diego), have females with pale oviscapts and males with sex comb teeth in the arrangement (from proximal end): 0–1, 2, 5, 5–6 (tarsomere I), 1, 3, 4 (tarsomere II) and, interestingly, 1 on tarsomere III; these values are at the upper end of the normal distribution for D. anomalata

Figures

Figures 38–53. Epandria of Drosophila ananassae complex species. Drosophila pandora sp.nov. (38) Lake Placid type strain CAQ408, lateral view; (39) type strain CAQ408, caudal view; (40) Lake Placid strain CAR274; (41) Lake Placid strain CAQ425. Drosophila ananassae (42) Beach Lane, Mauritius, Oct. 2012, J. Tann.Drosophila?ananassae (43) Kuranda, northern Queensland,AMS K275429; (44) Sigatoka, 35 km S Nadi, Fiji, AMS K275290; (45) Iron Range, fruit bait, 30.iv.1976, I.R. Bock, [possibly pinned on this date from a strain collected with P.A. Parsons in November 1975—there is no evidence that Bock returned to Iron Range in 1976], AMS K119308 (det. Drosophila ananassae by Bock in 1976). Drosophila pandora sp.nov.: (46) D. “papuensis-like” Kyorin University stock k-aat001, Townsville, Queensland.Drosophila pallidosa: (47) det. by?Wheeler, Pago Pago,American Samoa, DrosophilaSpecies Stock Center (San Diego), stock 14024-0433.01. Drosophila ananassae or D. pallidosa (48) Sigatoka, 35 km S Nadi, Fiji, June 2004, Schug, Gray-Smith, Kilon-Attwood, McEvey, AMS K282851. Drosophila schugi sp.nov. (49) Malololelei, Upolu, Samoa, 14–17 June 2003, paratype AMS K282923. Drosophila anomalata sp.nov. (50–52) ex type strain, Schiffer CHC221. Drosophila schugi sp.nov. (53) Malololelei, Upolu, Samoa, 14–17 June 2003, AMS K356977. Localities—see Fig. 1 and Appendix 1; all specimens in Australian Museum.

Figures 72–77. Male fore-leg and sex comb of tarsomere I (metatarsus) and II of Drosophila anomalata sp.nov. ex type strain CHC221, nr Deeragun, 16 km W of Townsville. Legs from five males; (73–74) left and right legs from one male [(74) image flipped].

Figures 78–81. Hypandria ofDrosophila anomalata sp.nov.three males from the type strain Schiffer CHC221 (ventral views); (81) dorsal view of hypandrium in Fig. 80.

Figures 89–91. Female oviposcapt (ovipositor) and setation of sixth abdominal tergite of Drosophila ananassae, D. pandora, D. anomalata and D. ironensis. Oviscapt form and colour: (89) Drosophila ananassae ex strain Schiffer CBR57 from Lake Placid; (90) D. pandora sp.nov. ex type strain Schiffer CAQ408 from Lake Placid; (91) D. anomalata sp.nov. ex type strain Schiffer CHC221 from near Deeragun, W of Townsville. Setation of sixth abdominal tergite: (92) D. ananassae ex strain Schiffer CBR54; (93) D. anomalata sp.nov. ex type strain; (94, 95) Drosophila ironensis ♀ and ♂ ex strain Schiffer CHH18 from Lake Placid, note the irregualr orientation of T6 setation in D. ironensis comparaed to the caudally oriented setation in other figured species; and (96) D. pandora sp.nov. ♂ ex type strain.All to same scale.