Asphondylia scopuli Dorchin & Mifsud, 2014

Dorchin, Netta, Mifsud, David & Askew, Richard, 2014, Saltbush-associated Asphondylia species (Diptera: Cecidomyiidae) in the Mediterranean Basin and their chalcidoid parasitoids (Hymenoptera: Chalcidoidea), Zootaxa 3869 (4), pp. 383-396 : 390-391

Asphondylia scopuli Dorchin & Mifsud , n. sp.

Gall and biology. This species induces fleshy, spherical bud galls, 4–5 mm in diameter, in leaf axils of Atriplex lanfrancoi ( Figs. 6–7 ). The galls are green to pinkish and covered by whitish fuzz similar to ungalled plant parts. Each gall contains a single larval chamber, the inside walls of which are lined by white mycelia. The species is apparently univoltine, with adults emerging in May. Larvae are heavily parasitized by numerous species of parasitic Hymenoptera so that repeated collecting over several years has yielded only a handful of adult gall midges. The galls superficially resemble those of A. caudicis Gagné in leaf axils of Atriplex canescens in North America ( Hawkins et al. 1986). It is possible that, like A. caudicis , A. scopuli has more than one generation a year and induces galls in different plant parts in different seasons, but such galls have not yet been found.

Adult: As in A. punica except for the following: third palpal segment 1.26–1.66 times as long as second; first antennal flagellomere 1.19–1.25 times as long as second in male, 1.47–1.52 as long as second in female.

Thorax: Wing length 2.30–2.42 mm in females (n=4), 1.98–2.19 mm in males (n=3).

Female abdomen: Sclerotized part of ovipositor 1.48–1.68 as long as sternite 7 (n=4).

Larva: unknown.

Pupa ( Figs. 17–18 ): 2.81–3.46 mm long (n = 4).

Material examined. Holotype: ♂, Malta, Migra Ferħa , 5–25.v.2012, D. Mifsud, deposited in TAUI . Paratypes: 4♀, 2♂, 5 exuviae (2 on microscope slide, 3 glued to cardboard), same data as holotype (2♀ NMNH, others TAUI) ; 1 pupa (coated, on SEM stub), same data as holotype, in private collection of DM .

Distribution. Endemic to Malta.

Etymology. The specific epithet is Latin for ‘of the cliff’, with reference to the unique habitat (seaside cliffs) of the host plant, an endemic to the Maltese Islands.

Notes. Asphondylia scopuli is smaller than A. punica but we could not find any substantial morphological differences between adults and pupae of the two species, except for those outlined above. Nevertheless, the galls induced by these species are markedly different, as are their host plants; Atriplex halimus is a widespread desert and salt-marsh shrub with C 4 photosynthesis, whereas Atriplex lanfrancoi is endemic to seaside cliffs in the Maltese islands, and represents an ancient clade within Atriplex of species with C 3 photosynthesis ( Kadereit et al. 2010). It is noteworthy that A. halimus is common in the Maltese islands but no galls were observed on it, including in localities where A. lanfrancoi galls were found (DM, personal observation). Our data leave us in no doubt that A. scopuli and A. punica are distinct species.

Figures

FIGURES 5–7. 5. The habitat of Atriplex lanfrancoi—an endemic plant of sheer seaside cliffs in the Maltese islands. 6. Fleshy bud galls of Asphondylia scopuli on Atriplex lanfrancoi. 7. Asphondylia scopuli gall on Atriplex lanfrancoi with pupal exuviae stuck in the gall.

FIGURES 13–18. 13. Asphondylia punica, male terminalia, dorsal. 14. Asphondylia punica, male terminalia, ventral. 15. Asphondylia punica, larval spatula and associated papillae. 16. Asphondylia punica, exuviae, head. 17. Asphondylia scopuli, pupal head, frontal. 18. Asphondylia scopuli, pupal head, lateral. Scale bars = 0.1 mm, except Figs. 17–18 = 200µm.