Baldratia salicorniae Kieffer, 1897

Dorchin, Netta & Freidberg, Amnon, 2008, The Chenopodiaceae-feeding gall midges (Diptera: Cecidomyiidae) of the Na’aman salt marsh, Israel, Zootaxa 1937, pp. 1-22 : 4-8

Baldratia salicorniae Kieffer, 1897

Baldratia salicorniae Kieffer, 1897: 7

Baldratia hyalina Kieffer 1912: 74 – junior synonym, Möhn 1969.

Lectotype of Baldratia salicorniae designated here – Ψ, Italy (unspecified locality and date), ex. Salicornia fruticosa stem gall. The lectotype is designated from one of the surviving syntypes of this species deposited in the National Museum of Natural History, Smithsonian Institution, Washington DC, USA (USNM) and has been labeled accordingly. The lectotype designation is done in order to clarify the application of the name B. salicorniae Kieffer and the concept of the genus Baldratia Kieffer as a whole, since B. slaicorniae is the type species. Other type material of B. salicorniae is considered lost together with the great majority of types described by Kieffer. Efforts that have been made to locate these types are described in Gagné (1994). The syntypes were sent to Kieffer from Italy by Prof. Baldrati, who found the galls and reared the gall midges. Kieffer subsequently gave some of the specimens (permanently mounted on microscopic slides) to E.P. Felt; hence they survived the fate of most of his collection. The following description ensures recognition of the designated specimen, and characters differentiating the species from other congeners are detailed below under the remarks section.

Adult. – Head ( Fig. 11 ): Eye facets circular, less ordered and farther apart on vertex than laterally, gap between eyes on vertex 0–2 times as wide as facet. Mouthparts: Palpus 1-segmented, 1.5–2.0 times as long as wide, rounded or tapered, with several long setae. Antenna ( Figs. 11–12 ): similar in both sexes; scape wide conical to pyriform, pedicel globular, flagellomeres 9–11 barrel-shaped, about 1.3 times as long as wide, each with two whorls of connected circumfila and two whorls of setae; setae in proximal whorl thin and straight or evenly curved, setae in distal whorl thicker, strongly curved, originating from much larger sockets, often arranged in a group rather than a row. Adjacent flagellomeres sometimes partially fused. Two apical flagellomeres in male and 2–3 in female almost always fused. Number of flagellomeres may differ between antennae in same individual.

Thorax: Wing: length 1.2–1.9 mm in females (n=18), 1.4–1.8 mm in males (n=13); very light brown shade, covered by dark microtrichia, denser along veins M and Cu. C, Sc and R5 brownish, with dark scales and hairs. R5 joins C at wing mid length, M present as fold, Cu unforked, posterior wing margin with long fine hairs up to meeting point of Cu with C. Legs: densely covered by dark scales and hairs. Tarsal claws ( Fig. 13 ) toothed, thick, evenly curved; teeth thin and strongly curved near base, empodia much shorter than claw.

Female abdomen ( Fig. 14 ): Most of abdomen covered by white scales. Scale pattern on dorsum comprising three black spots on white background on anterior part of each tergite; medial spot triangular, smaller than two lateral semi-spherical spots. Tergites 1–7 rectangular, with 1–2 posterior rows of setae and 1 trichoid sensillum at mid-anterior part; tergite 8 much narrower than preceding tergites, often only sclerotized posteriorly, without posterior row of setae, with anterior trichoid sensilla. Sternites 2–7 rectangular, sometimes less sclerotized in mid part, with 1–3 posterior rows of strong setae and several strong setae anteriorly; sternite 8 undifferentiated from surrounding membrane. Area anterior and posterior to lateral group of setae on segment 8 with longitudinal wrinkles and grooves. Ovipositor ( Fig. 15 ): Lateral group of setae large, comprising more than 100 curved, hyaline setae, surrounded by minute smaller and denser hyaline setae. Segment 9 anteriorly with dorsal and ventral sclerites. Sclerotized rods widen posterad. Posteroventral part ventral to cercus with several long, strong setae. Lateral plate sheathing entire base of cercus, with short, thick dorsal spur, bearing 17–24 straight, split setae. Aculeus slightly curved posteroventrally, bearing 11–16 thin, hooked setae that are strongly curved at mid length. Apical lamella ovoid, as long as aculeus, evenly setose.

Male abdomen: Scale pattern as in female. Tergites 1–7 rectangular, entire, with single posterior row of setae and a trichoid sensilla on mid anterior part. Tergite 8 much narrower than preceding tergites, sclerotized only in mid part, without posterior row of setae, with anterior trichoid sensilla. Sternites 2–8 rectangular, sternite 8 smaller than 7, all with 2–3 posterior rows of setae; number of posterior setae larger on posterior than on anterior sternites. Terminalia ( Fig. 16 ): Gonocoxite wide, massive, ventrally and laterally with scattered long setae; mediobasal lobe relatively small, evenly setulose. Gonostylus ( Figs. 17–18 ) narrowed considerably toward apex, dorsally setulose near base, ridged elsewhere, with many long setae; verntrally ridged with fewer setae; tooth blunt. Fused cerci considerably wider than hypoproct, widely separated, evenly setulose with several strong setae. Hypoproct entire, rounded, narrowed posteriorly. Paramere wide triangular, evenly setose, apically with one seta on small protruding lobe. Aedeagus longer than paramere, narrowed toward apex, rounded at tip.

Larva (third instar) ( Figs. 6 , 19–20 ) – Elongate and slender, body tapered posteriorly, orange; length: 2.7– 3.5 mm (n=6). Integument covered by tiny spicules. Posterolateral apodemes 1.5 times as long as head capsule ( Fig. 20 ). Spatula ( Figs. 20, 21 ) with long shaft, widened distally, with three strongly sclerotized teeth; middle tooth slightly to significantly smaller than lateral teeth (varies among individuals, Fig. 21 ). On each side of spatula asetose sternal papilla, two tiny, asetose inner lateral papillae and one larger asetose outer lateral papilla; inner pleural papilla asetose, outer pleural papillae with long setae. Terminal papillae four, all asetose.

Pupa ( Figs. 22–24 ) – Dark orange; length: 3.5 mm (n=2). Antennal horns prominent, facial horn small, pointed. Prothoracic spiracle tapered distally, four times as long as wide at base. Cephalic seta short and fine. Frons with two setose frontal papillae and two asetose lateral papillae on each side. Abdominal segments covered by spicules. Anal segment divided into two tapered lobes.

Material examined – 2 Ψ, 2 ɗ, 1 pupa, Italy, unspecified locality and date, collected by Baldrati from Salicornia fruticosa stem galls; All other material from Israel, Akko , N. Dorchin, reared from Sarcocornia perennis stem galls, unless otherwise noted. 10.II.1995, 1 Ψ, 1 ɗ, 2 pupal exuviae, 3 larvae; 3.III.1995, 1 Ψ; 7.IV.1995, 1 Ψ, 3 ɗ; 20.VII.1996, 5 Ψ, 4 ɗ; Atlit, 21.X.1996, 4 Ψ, 6 ɗ; 26.VII.1997, 2 Ψ, 2 ɗ, 3 larvae; 1,28.Vlll.1998, 5 ɗ; 20.VII.2002, N. Dorchin and A. Dorchin, 4 Ψ, 1 ɗ; N. Dorchin and A. Freidberg, 12.VIII.2002, 2 Ψ, 3 ɗ; A. Freidberg, 7.IX.2002, 2 Ψ, 3 ɗ.

Distribution. – circum-Mediterranean and Eritrea.

Etymology: The species was named after the host genus, Salicornia , from which it was originally described.

Biology. – The species develops in stem galls on Sarcocornia perennis ( Figs. 5–6 ). Each gall occupies a single stem joint. The joint is fleshy, inflated, at least partially red, and in most cases can easily be distinguished from non-infested joints. First and second instar larvae were sometimes found in the same joint before chambers start forming in the gall. Third instar larvae were found in distinct chambers in the stem, usually one larva per gall. Galls containing larvae and pupae were rather abundant throughout the year, and adults emerged from March to September. From October to March, galls contained first instar larvae. These observations indicate that the species has several overlapping generations a year.

Remarks. – Baldratia salicorniae is the type species of the genus Baldratia , which was originally described by Kieffer (1897) from Salicornia fruticosa . This host plant belongs to a complex of closely related, taxonomically controversial salt-marsh species with jointed nodes and scaly leaves, and is now considered to be in the genus Sarcocornia (Boulus 1999) . Houard (1922) included drawings of the galls with records from Libya, Tunisia, and Eritrea. Similar galls recorded on the related host Arthrocnemum glaucum ( Houard 1908) possibly also belong to B. salicorniae . In the present study we reared the gall midges from Sarcocornia perennis . Although this is not the original host from which the species was described, the following circumstances and evidence support our conclusion that the species we reared is indeed Baldratia salicorniae . Given the subtle morphological differences among the host plants, their similar habitat and distribution, and the similar descriptions of the galls from all hosts, it is possible that the original host was misidentified and/or that B. salicorniae is found on all of these plant species. This assumption is further supported by data given in Möhn’s (1969) revision of the genus Baldratia , in which the list of host plants for B. salicorniae includes Halocnemum strobilaceum and several Salicornia and Arthrocnemum species, including Sarcocornia perennis ( Arthrocnemum perenne of Möhn, 1969), and in which the Israeli town of Haifa (20 km south of Akko ) is mentioned among the localities where galls had been found. Furthermore, the original description of B. salicorniae , and in particular the consequent, much more detailed redescription in Kieffer (1912, as B. hyalina ), match the species we reared, including the conspicuous bilobed last segment of the pupal abdomen depicted in Kieffer (1912).

Möhn (1969) placed B. salicorniae in the salicorniae subgroup together with B. suaedae Möhn , B. aelleni Möhn , B. przewalskii Marikovskij , B. kozlovi Marikovskij and B. haloxyli Möhn , all of which possess a threetoothed spatula. In a subsequent study of adults, Fedotova (1991) also placed this species in the salicorniae subgroup, but assigned to it only one more species, B. suaedifolia Fedotova (and later ( Fedotova 1992) also B. balchanensis Fedotova ), based on characters of the ovipositor. Species in this subgroup share lateral plates that embrace the entire base of the cercus, are covered by split spines, and bear a thick, dorsal spur, which is longer and thinner in B. suaedifolia and B. balchanensis than in B. salicorniae . The cercus in these species is situated at an obtuse angle relative to the ovipositor “trunk” (segment 9 of the abdomen), allegedly distinguishing them from members of the climacopterifolia subgroup of Fedotova (e.g., B. araliensis Fedotova , B. climacopterifolia Fedotova , B. halimocnemiis Fedotova , B. jaxartica Fedotova , B. nitrariacarpa Fedotova ). In the latter group, the cercus forms a right angle to the trunk and the lateral plates are not as developed.

The presumed closest relatives of Baldratia salicorniae develop in different host plants and host organs and are known so far only from Eastern Europe and central Asia; B. suaedifolia develops in leaves of the annual Suaeda acuminata in Kazakhstan ( Fedotova 1991) without causing external deformation, and B. balchanensis induces leaf swellings in Salsola aucheri in Turkmenia ( Fedotova 1992). In Israel, the only other Baldratia species known to share the above-mentioned morphological attributes with B. salicorniae develops in barely conspicuous galls in leaves of the salt-marsh annual Suaeda aegyptiaca and is yet to be described (N. Dorchin, unpubl.).

Figures

FIGURES 11 – 18. Baldratia salicorniae. 11. Head. 12. Female apical flagellomeres. 13. Acropod. 14. Female abdomen, lateral. 15. Ovipositor. Not all setae on aculeus shown 16. Male terminalia, dorsal. Setae on parameres are shown as would be seen if the cerci were removed 17. Gonostylus, ventral. 18. Gonostylus dorsal. Scale bars = 0.1 mm (scale bar for Fig. 13 = 0.05 mm).

FIGURES 5 – 10. Galls and infestation. 5. Baldratia salicorniae gall (arrow) in stem of Sarcocornia perennis. 6. A section through B. salicorniae gall, showing a larva. 7. Careopalpis akko gall (arrow) in leaf of Suaeda splendens. 8. Houardiella gracilis exuviae in dried stem joint of Arthrocnemum macrostachyum. 9 – 10. Stefaniella brevipalpis stem and leaf galls on Atriplex portulacoides.

FIGURES 19 – 24. Baldratia salicorniae. 19. Larva, ventral habitus. 20. Larva head and spatula with associated papillae. 21. Spatulae showing variable proportions of teeth. 22. Pupa, ventral. 23. Pupa, lateral. 24. Pupa head, lateral. Scale bars = 0.1 mm.