Baldratia arida Dorchin, 2019

Dorchin, Netta, Danon, Gilad & Dor, Roi, 2019, Gall midges (Diptera: Cecidomyiidae) associated with Suaeda (Chenopodiaceae) in Israel and the Mediterranean Basin, Israel Journal of Entomology (Oxford, England) 49 (2), pp. 99-134 : 112-116

Baldratia arida Dorchin , n. sp.

( Figs 14–23, 44, 45)

LSID: urn:lsid:zoobank.org:act:D3AD7F22-F0C3-4C21-B7CE-76D4A62F202C .

Etymology: The species is named after its typical habitats: arid slopes of the Judean Mountains and along the Dead Sea valley.

Description:

Gall and biology: This species develops without gall formation in leaves of Suaeda asphaltica and S. aegyptiaca . At most, a slight swelling can be seen in close examination of S. aegyptiaca leaves, but the presence of the gall midge usually becomes evident only once the adults emerge and the empty exuviae are found stuck in the leaf. One individual develops per leaf.Although the annual or biennial S. aegyptiaca is available for galling almost throughout the year, we reared the gall midges from this plant only in April, June and November but not during most of the summer (July–September). The second host plant, Suaeda asphaltica , is a subshrub whose above-ground parts are completely dry between May and December, and gall midges were reared from it only between February and April. These data suggest that B. arida completes several generations between November and June, and first-instar

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larvae probably spend the summer in diapause inside viable parts of the host plants. The species can be abundant in some sites but usually emerges in smaller numbers compared to those of other species on the same host plants.

Adult. General color of female pinkish, of male greyish to light orange. Face, occiput, thorax and ventral and lateral parts of abdomen covered by white scales. Legs densely covered by white scales ventrally, black scales dorsally. Dorsal part of abdomen with black-and-white scale pattern created by three black triangles on white background on each segment.

Head: Eye facets round; gap between eyes on vertex 1–2 facets wide. Antenna: Scape wide trapezoid, pedicel spherical, both covered by white scales; number of flagellomeres 10–13 in female (n=36), 10–11 in male (n=32), number occasionally differs between antennae of same individual; flagellomeres ( Fig. 14) cylindrical to barrel-shaped in male, shorter to almost quadrate in female; each flagellomere with two whorls of appressed circumfila with longitudinal connection, one whorl of strong setae originating from prominent sockets between two circumfila whorls, one whorl of smaller setae proximal to circumfila, and otherwise evenly covered by microtrichia; apical flagellomere almost always composed of 2–3 entirely or partially fused units, apically rounded, with 4–8 circumfila and several whorls of long setae ( Fig. 15). Frontoclypeal membrane with long setae and scales. Palpus strongly reduced, 1-segmented, about 2–3 times as long as wide, with few long setae and otherwise evenly setulose ( Fig. 16). Labella about as long as wide, setulose, with several long setae.

Thorax: Greyish, covered by white scales and setae. Wing transparent, with sparse hair-like setae on entire surface and long hair-like setae along posterior margin; wing length 1.39–2.76 mm in females (n=37), 1.54–2.64 mm in males (n=33); C broken distal to junction with R 4+5; R 4+5 joining C around mid-length of wing; C and R 4+5 densely covered by mixed black and white scales to meeting point; M 4 absent, M 1+2 straight, CuA curved at proximal third. Stem of halter light orange, without scales; knob covered by black and white scales. Legs: Tarsal claws ( Fig. 18) moderately and evenly arched, with small tooth, slightly to strongly curved close to base; empodia clearly shorter than bend in claw; pulvilli distinct, about 0.3 as long as claw.

Female abdomen ( Fig. 17): Tergites 1–7 with anterior pair of trichoid setae, 1–2 posterior rows of strong setae, and evenly distributed scales; tergite 8 shorter than 7, extending farther ventrally, with anterior pair of trichoid sensilla and few small setae, without posterior row of strong setae. Sternites 2–7 without anterior trichoid setae, with posterior row of setae, several setae at proximal half, and evenly distributed scales; sternite 8 undifferentiated from surrounding membrane. Ovipositor ( Fig. 19): segment 8 with large lateral group of hyaline, curved setae on prominent sockets; segment 9 with pigmented patches basally, pigmented rod-like sclerite along segment, and several long and strong setae apicoventrally. Cercal segment in obtuse position relative to segment 9, strongly sclerotized lateral plate sheathing almost entire base of apical lamella, with thick, basal spine extending to half-length of aculeus, and about 20 straight, paired setae laterally; aculeus thick, evenly curved ventrally, with two rows of 5–6 strongly hooked setae on distal half. Apical lamella ovoid, setose and setulose.

Male abdomen: Tergites 1–8 as in female. Sternites 2–7 as in female, except setation stronger on posterior sternites. Sternite 8 smaller but more setose than preceding. Terminalia ( Fig. 20): Gonocoxite elongate, cylindrical, about same width throughout length, with numerous strong setae laterally; mediobasal lobe without typical bulge dorsally, ventral part elongate, narrows posteriorly, sheathing aedeagus almost to apex, longitudinally divided by deep grooves into two lobes on each side, densely setose. Gonostylus strongly arched, widest at mid-length, narrowed abruptly from mid-length toward apex, with wide apical tooth, numerous setae more closely situated at base of tooth, setulose along distal half dorsally and ventrally, striate elsewhere. Aedeagus only slightly longer than mediobasal lobes, rounded apically. Hypoproct entire, narrow, rounded apically, setose and setulose. Cerci separated by rounded notch on distal third, rounded apically, setose and setulose.

Larva (third instar) ( Figs 21). Light to bright orange. Elongate. Integument completely covered by tapered verrucae. Antennae about 3 times as long as wide. Posterolateral apodemes about as long as head capsule. Spatula ( Fig. 22) prominent, tridentate, long shafted, shaft very wide immediately posterior to teeth, mid tooth distinctly shorter than lateral teeth. On each side of spatula 1 asetose sternal papilla, 3 asetose lateral papillae, 2 of which on separate elevated bumps, the third without such bump, and 1 asetose ventral papilla. Pleural and dorsal papillae with long setae. Terminal abdominal segment ( Fig. 23) with 2 papillae bearing long setae on each side.

Pupa ( Figs 44, 45). Light to dark orange. Antennal bases forming wide, tapered horns, pointed ventrally. Vertex with short cephalic seta on prominent bulge. Prothoracic spiracle tapered, narrowed abruptly at distal third, where trachea opens. Face with prominent, straight anterior horn and shorter, slightly curved and wide-based posterior horn; without apparent facial papillae.Abdominal segments entirely covered by tiny, tapered spicules.

Holotype: ♀, Israel: Lido junction, 1 km S, Rt. 90 [31°46'12.8"N 35°29'56.0"E], 7.ii.1996, N. Dorchin, reared from leaf of Suaeda aegyptiaca . On permanent microscope slide in Euparal (SMNHTAU).

Paratypes: Israel: From Suaeda aegyptiaca : 1♀, same data as holotype ; 1♀ 5♂, Lido junction, 1 km S, Rt. 90, 19.ii.1996, N. Dorchin ; 10♀ 10♂, 9 larvae (on 2 microscope slides), 28 pupal exuviae (on 5 microscope slides), Enot Qane, 1.vi.2014, A. Freidberg.

From Suaeda asphaltica : 7♀ 2♂, Mizpe Yeriho , 1 km E, Rt 1, sea level, 13.ii.2013, G. Danon ; 10♀ 6♂, Mizpe Yeriho , 1 km E, Rt 1, sea level, 7.iv.2013, G. Danon (1♀ 1♂, USNM, 1♀ ZFMK, others SMNHTAU) ; 2♀ 6♂, Mizpe Yeriho , 1 km E, Rt 1, sea level, 16.ii.2014, G. Danon ; 3♀ 1♂, Nabi Musa , 7.iv.2013, G. Danon ; 1♂, 1 exuviae, Mizpe Yeriho , 1 km E, Rt 1, sea level, 1.ii.2017, N. Keidar; 2 exuviae (on same microscope slide), Mizpe Yeriho, 1 km E, Rt. 1, sea level, 14.ii.2017, N. Bonda; 2 exuviae (on same microscope slide) , 1♀ 1♂, Nabi Musa , 14.ii.2017, N. Keidar .

Other material examined: Israel: 1♀ 1♂, Mizpe Yeriho, 1 km E, Rt 1, sea level, 13.ii.2013, G. Danon, ex Suaeda asphaltica .

Distribution: Currently known only from the northern Dead Sea area (on S. aegyptiaca ) and the Judean Desert (on S. asphaltica ) in Israel. Probably also occurs in Jordan on the same host plants.

Remarks: This species belongs to a morphologically uniform group within Baldratia , in which the female ovipositor has a strong spike at the base of the cercal segment in addition to the aculeus and paired spines on the lateral plate. It differs from other members of this group in Israel ( B. salicorniae Kieffer and B. suaedae Möhn ) by pupal and larval characters. The pupa of A. arida has anterior and posterior facial horns and no facial papillae, whereas in B. salicorniae it does not have a posterior facial horn but bears facial papillae, and in B. suaedae the pupa has a minute posterior facial horn and clearly setose facial papillae, and its adults are much smaller than those of B. arida and B. salicorniae . The arrangement of lateral papillae in the larva is similar in B. arida and B. salicorniae but differs between them and S. suaedae . Other species from Suaeda in this region include Baldratia occulta Dorchin from S. monoica in Israel (Dorchin 2001) and Baldratia karamae Elsayed from S. acuminata in Egypt ( Elsayed et al. 2015). Baldratia occulta differs from B. arida in that its pupa does not have a posterior facial horn and the female ovipositor lacks an additional spine at the base of the aculeus. Baldratia karamae is much smaller than B. arida based on its published description, and is found almost throughout the year ( Elsayed et al. 2015), whereas B. arida was reared only in spring. Molecular data (Dorchin & Dor, unpubl.) confirm that B. arida is distinct from B. suaedae , B. occulta and B. salicorniae . The remaining Baldratia species currently known from Suaeda are B. aelleni Möhn from Suaeda microphylla in Iran, known only from larvae ( Möhn 1969), and B. suaedifolia Fedotova and B. terteriani Mamaev & Mirumian from Central Asia.