Platystoma torridum, Bodner, L. & Freidberg, A., 2016

Bodner, L. & Freidberg, A., 2016, Taxonomy and immature stages of the Platystomatidae (Diptera: Tephritoidea) of Israel, Zootaxa 4171 (2), pp. 201-245 : 227-229

Platystoma torridum n. sp.

( Figs. 16 , 27 , 38 , 49 , 60 , 71, 85, 88–94, 98)

Diagnosis. The specimens of this species were compared to Hendel’s (1913) original description of Platystoma curvinerve (described from Turkmenistan), topotypical specimens of that species, and to Hennig (1945), the most modern key to species of Platystoma (Hennig's redescription of P. curvinerve is practically a repetition of Hendel's description). P. torridum greatly resembles P. curvinerve , differing from it in the following characters: ground color of thorax black, rather than notopleuron area orange to red, and densely microtrichose, as opposed to shiny; scutum and scutellum heavily microtrichose without blackish-green reflection; all the pleura punctured as well as microtrichose, as opposed to just the anepisternum; abdomen conspicuously microtrichose, not shiny; ventral half of face shiny black, lacking median line of microtrichia, not reddish-yellow; gena height less rather than more than a quarter of the eye height.

Description. Head ( Figs. 16 , 27 ): Color and vestiture: Head mostly yellow with yellowish-brown to dark brown areas. Median occipital sclerite orange to reddish with fine microtrichia. Frons microtrichose mostly laterally, with orange to brown dots around bases of setulae. Ocellar triangle delimited by dense silvery-white microtrichia. Lunule yellow to orange with yellowish median line of microtrichia. Scape and pedicel yellow to orange, 1st flagellomere yellow to orange with blackish area on dorsal margin. Antenna almost entirely microtrichose except inner pedicel. Face: dorsal 0.5 yellowish brown with dense gray microtrichia; ventral 0.5 shiny black medially and yellowish to orange lateroventrally, without microtrichia. Clypeus with 1 (pair) oval dorsomedial spot, 1 (pair) narrow lateral band, and single narrow band of microtrichia medioventrally. Chaetotaxy: 1 (pair) orbital (posterior) and 1 (pair) postocellar seta present. Lunule bare, rarely with thin white setulae. Postgena with yellowish-white setulae. Occiput bare. Ratios: Head: 1.26–1.38; frons anterior: 1.19–1.38; frons posterior: 1.16–1.31; ocellar triangle/frons: 0.19–0.31; eye: 1.75–2.25; 1st flagellomere: 1.75–2.67; gena/eye: 0.18– 0.24; parafacial/gena: 0.14–0.21; medial vertical/lateral vertical: 0.96–1.48; posterior orbital/medial vertical: 0.21– 0.63; ocellar/medial vertical: 0.22–0.42; ocellar/ocellar triangle: 0.50–0.94; postocellar/medial vertical: 0.23–0.28.

Thorax: Color and vestiture: Ground color black, with dense gray microtrichia. Scutum with 3 microtrichose stripes. Posterior corner of postpronotal lobe and median articulation of anepisternum and katepisternum shiny yellow without microtrichia. Scutellum microtrichose; more pronounce at posterior margin, around basal scutellar setae and in thin median longitudinal line. Subscutellum and mediotergite black with grayish microtrichia. Proepisternum and anterior anepisternum with dense white microtrichia. Other pleura with reticulate pattern of microtrichia. Chaetotaxy: Postpronotal lobe with 0–2 setae, and with anteriorly yellowish and posteriorly brown setulae. Presutural supra-alar seta absent. Postsutural supra-alar seta present. Anepisternum with short setulae. Katepisternum with yellowish-white to orange setulae. Ratios: Scutum: 1.00–1.19; postsutural supra-alar/intraalar: 0.62–0.84; postalar/intra-alar: 0.97–1.44.

Legs: Color and vestiture: Leg type pale; generally yellow. Fore tarsus brown. Fore coxa microtrichose, mid and hind coxae mostly shiny yellow, sometimes with fine, inconspicuous microtrichia. Chaetotaxy: Fore coxa anterodorsally setulose, mid and hind coxae ventrally setulose; fore coxa with short, yellowish-white to brown setulae proximally, and with long dark brown setulae distally; mid coxa predominantly with long dark brown setae and setulae; hind coxa with thin, moderately long, yellowish-white setulae. Trochanters with mixed yellowishwhite and dark brown setulae. Femora mostly short dark brown setulose, with long yellowish to pale brown setulae ventrally. Fore and hind tibiae with 1–2 short spines.

Wing ( Fig. 38 ): Pattern: Generally pale grayish-brown, more or less uniformly reticulate. Combined area of hyaline spots greater than combined area of pigmented pattern. 5–7 more conspicuous costal dark spots over pterostigma, cells r1 and r2+3. Costal cell hyaline with 3–5 separate dark spots. Venation: Veins and sclerites mostly yellow or yellowish-brown. Costa entirely yellow. Vein M ends distinctly anterior to wing tip. Dorsal calypter slightly wider and shorter than ventral calypter. Dorsal calypter margins with brownish fringes. Halter base and knob yellowish-orange, stem yellowish-white. Chaetotaxy: Base of costa near costagial break, ventrally with moderately long seta. Ratios: Wing: 2.40–2.65.

Abdomen: Structure: Male T4 slightly shorter than T3 (or about as long) and about half as long as T5. Female T4 about as long as T3 or T5. Color and vestiture: Abdomen densely and uniformly microtrichose. Male terminalia ( Figs. 49 , 60 , 71): Epandrium in ventral view square-shaped, in lateral view narrow and L-shaped; ventral concavity wide and deep; subepandrial sclerite narrow, posteroventrally exposed in lateral view; lateral surstylus short and narrow, mesally concave, anterodorsally fused to epandrium; medial surstylus indistinct; prensisetae in ventral view fully exposed. Terminal filaments equally long, conspicuously shorter than distiphallus. Female terminalia (Fig. 85): 3 spermathecae present, 2 connected by short common duct attached to sclerotic ring; spermatheca spherical and tuberculate, with bell-shaped base and cone-shaped inner structure. Ratios: Male: T3/ T4: 1.00–1.29; T4/T5: 0.56–0.80; T3+4/T5: 1.28–1.60; epandrium: 0.61–0.68; preglans: 1.14–1.33; glans: 2.14– 2.38; preglans/glans: 0.31–0.36; acrophallus/preglans+glans: 2.6 1–2.90; distiphallus/preglans+glans: 5.54–6.17. Female: T3/T4: 1.00–1.17; T4/T5: 1.00–1.29; T3+4/T5: 2.00–2.59; aculeus: 5.92–6.08; cercal unit: 2.48–3.00; cercal unit/aculeus: 0.33–0.36.

Measurements (mm). Body length: 4.50–7.30; wing length: 4.10–4.80.

Material examined. Holotype: Ƌ, ISRAEL, Har Horesha , 900–1000m, 18.iv.1998, A. Freidberg . Paratypes: same collection data as holotype (30Ƌ, 5♀); additional paratypes (all from Israel): ' Arad (or Arad): 16.iv.1997, AF, in dung (1Ƌ), 21.iv.1981, AF (19Ƌ, 7♀), F. Kaplan (10Ƌ, 6♀) ; Zomet Haluqim , 5KmNW, 14.iv.2003, AF (2Ƌ), L. Friedman (1Ƌ, 1♀); Nahal Ye'elim (or Nahal Ye'elim, nr. ' Arad) : 6.iv.1988, F. Kaplan (2Ƌ), 8.iv.2012, AF (7Ƌ, 1♀), 8.iv.1996, AF (1♀), 8.iv.1998, AF (2Ƌ, 2♀), 12.iv.1990, AF (3Ƌ, 4♀), 12.iv.2012, L. Bodner (6Ƌ, 3♀), 21.iv.1992, AF (1Ƌ), [Top Yaalim], 21.iv. [19]92, Guy B. (1♀), 21.iv.2005, AF (3Ƌ), 21.iv.2005, L. Friedman (1Ƌ), 23.iv.2012, AF (6Ƌ, 1♀), [N.Ye'elim], 2–3 Km E. ' Arad : 28.iv.1986, AF (11Ƌ, 1♀), 19.iv.1995, AF (8Ƌ, 1♀), 22.iv.1987, AF (2Ƌ, 1♀), 30.iv.1987, AF (3Ƌ, 1♀); Nizzana , Northern Negev, 25.iv.2002, [ PPIS, Trap] (3Ƌ); ' En [Ein] Mor, 2KmW, 22.iv.1986, AF (1♀) ; ' En Mor, Nahal Hawarim , 30°50.7'N 34°46.6'E, 4.iv.2010, E. Morgulis (1♀) ; Nahal Nizzana : Rt. 171, 750m, 2.iv.2014, AF (16Ƌ, 4♀), 21.iv.1982, I. Rubin (1Ƌ); Har Hemet, nr. Makhtesh Ramon, 14.iv.1992, AF (1♀) ; Har Horesha (' Rosh Horesha', or ' HarHoresha' ), Rt.171: 930m, 2.iv.2014, AF (1♀) , 30°36'N 34°31'E, 6.iv.2005, AF (8Ƌ, 3♀), L. Friedman (1♀), 925m, 30o30.032'N 34o35.450'E, 26.iv.2012, L. Bodner (2Ƌ, 2♀), 935m, 30°30'N 34°36'E, 26.iv.2012, AF (1♀); Nahal Eshharim [Esh-harim], West side of Ramon Crater, 950m, 30o30.03'N 34o35.45'E, 2.v.1995, M. E. Irwing (1♀); Nahal Eshharim , 2.v.1995, I. Yarom, Malaise trap (1♀) ; Har Harif : 30o30'N 34o35'E, 11.iv.2002, AF (2Ƌ, 1♀), Rt. 10 N junction , 30o30'N 34o35'E, 11.iv.2002, L. Friedman (2Ƌ), Rt. 171, 900m, 29.vi.1994, AF (1Ƌ, 1♀); Borot Loz , 5 Km E, 6.iv.2005, AF (13Ƌ, 7♀), L. Friedman (7Ƌ, 2♀) ; Nahal Loz, Har Ramon , 900m, 14.iv.1992, AF (13Ƌ, 11♀) ; Har Ramon , 4.vi.1992, AF & F. Kaplan (1Ƌ).

The holotype ( Fig. 98 ) is double-mounted (minutien pin and polyporus block), in excellent condition, and deposited at the SMNHTAU. Most paratypes are deposited at the SMNHTAU; some paratypes will be deposited at the museums listed in the Material and Methods section.

Distribution. Israel.

Distribution in Israel. Judean Desert, Northern and Central Negev.

Adult activity in Israel. April to June.

Etymology. This species is named " torridum " (Latin: "dry and parched"), as in Israel it is the only species of the Platystomatidae that inhabits and is restricted to the desert region.

Biology and Ecology. This is the only species of Platystomatidae that is restricted to desert areas. Adults were nearly always collected on large shrubs of Retama raetam (Fabaceae) . However, they have never been reared from this plant. Moreover, since our life-history study showed that the larvae are saprophagous (see below), we speculate that the adults spend time on this plant for shelter and food in the form of nectar and honey-due. Adults have also been observed feeding on mammal dung, probably as a proteinaceous supplement to their diet.

Life cycle. Oviposition: Females were observed ovipositing in crevices available in the cage, such as in the aluminum mesh that covered the ventilation openings. The eggs were laid in batches of around 50 ( Fig. 88 ). Rearing: We mainly presented the larvae with various decaying materials, but also fresh root nodules. However, the 1st instar larvae did not appear to feed on these substrates and eventually died. We finally offered the larvae a moist bran-based diet previously developed in our laboratory by Morgulis (2012) and used for Ulidiidae , and this time we were successful in rearing a complete cycle of Platystoma torridum . Duration: Egg incubation 3–5 days; 1st +2nd instar larvae 18–22 days; 3rd instar larva 7–10 days; Pupa 12–17 days; total duration from egg to adult 40– 54 days.

Description of Immature Stages ( Figs. 88–94 ). Eggs ( Fig. 88 ): Length: 0.92–0.99 mm, width: 0.16–0.18 mm (n=10). Elongate, white, rice-grain-like, with anterior end pointed and posterior end rounded. 1st instar larva: Length: 0.92–0.99 mm, width: 0.16–0.18 mm (n=10). 2nd instar larva: Length: 5.75–6.13 mm, width: 0.75–0.97 mm (n=4). 3rd instar larva ( Fig. 90 ): Length: 13.56–14.04 mm, width: 1.44–1.78 mm (n=4). Body cylindrical, tapering anteriorly and truncate posteriorly. Body surface generally smooth, protuberant only on ventral creeping welts. Cephalopharyngeal skeleton ( Fig. 91 ): Mandible strongly sclerotized, smooth, without accessory tooth; apical tooth sharp, elongate and strongly curved; dental sclerite brownish, weakly sclerotized; hypopharyngeal sclerite elongate, more than 3 times as long as wide; parastomal bar about as long as hypopharyngeal sclerite, narrow, pointed anteriorly; ventral cornua bears window. Anterior spiracle ( Fig. 92 ): Fan-shaped with 1 main branch and 6–7 digits. Posterior spiracle ( Figs. 93, 94 ): Spiracular plates projecting posteriorly from anal plate. Peritrem black, heavily sclerotized and thick, about 0.25 as plate diameter. Spiracular slits about 2 times as long as wide, arranged in radiating pattern at angle of about 120 0. Puparium ( Fig. 89 ): Length: 6.06 mm, width: 2.05 mm (n=1). Puparium brown, barrel shaped with wrinkled surface. Posterior spiracles prominent.

Overall, the immatures of this species match the descriptions of congeners in previous reports ( Ferrar 1987). However, two differences were found in the 3rd instar larva when comparing our species with the description of P. lugubre Robineau-Desvoidy ( Hennig, 1945) : (1) the anterior spiracle of P. lugubre has 12 digits, while that of P. torridum has only six or seven; (2) according to Hennig, the body length measured in P. lugubre larvae was 16 mm and the body width was 2 mm, while the third instar larvae of P. torridum measured 13.6–14.4 by 1.44–1.78 mm.

Figures

FIGURES 8 – 18. Head, frontal view. 8. Platystoma arcuatum. 9. P. dalia. 10. P. dimidiatum. 11. P. elizabethae. 12. P. geula. 13. P. malatiense. 14. P. nitidiventre. 15. P. pubescens. 16. P. torridum. 17. P. trigonum. 18. Rivellia israelica. Postocular setae not always visible in this view.

FIGURES 19 – 29. Head, lateral view. 19. Platystoma arcuatum. 20. P. dalia. 21. P. dimidiatum. 22. P. elizabethae. 23. P. geula. 24. P. malatiense. 25. P. nitidiventre. 26. P. pubescens. 27. P. torridum. 28. P. trigonum. 29. Rivellia israelica.

FIGURES 30 – 40. Wing. 30. Platystoma arcuatum. 31. P. dalia. 32. P. dimidiatum. 33. P. elizabethae. 34. P. g e ul a. 35. P. malatiense. 36. P. nitidiventre. 37. P. pubescens. 38. P. torridum. 39. P. trigonum. 40. Rivellia israelica.

FIGURES 41 – 51. Epandrial complex, ventral view. 41. Platystoma arcuatum. 42. P. dalia. 43. P. dimidiatum. 44. P. elizabethae. 45. P. g e ul a. 46. P. malatiense. 47. P. nitidiventre. 48. P. pubescens. 49. P. torridum. 50. P. trigonum. 51. Rivellia israelica.

FIGURES 52 – 62. Epandrial complex, lateral view. 52. Platystoma arcuatum. 53. P. dalia. 54. P. dimidiatum. 55. P. elizabethae. 56. P. g e ul a. 57. P. malatiense. 58. P. nitidiventre. 59. P. pubescens. 60. P. torridum. 61. P. trigonum. 62. Rivellia israelica.

FIGURES 95 – 100. Habitus of newly-described species, holotypes. 95. Platystoma dalia. 96. P. elizabethae. 97. P. geula. 98. P. torridum. 99. P. trigonum. 100. Rivellia israelica.

FIGURES 88 – 94. Immature stages of Platystoma torridum. 88. Eggs. 89. Pupa. 90. 3 rd instar larva. 91. Cephalopharyngeal skeleton. 92. Anterior spiracle. 93. Posterior spiracle, posterior view. 94. Posterior spiracle, lateral view.