Liriomyza merga, Lonsdale, 2011

Lonsdale, Owen, 2011, The Liriomyza (Agromyzidae: Schizophora: Diptera) of California 2850, Zootaxa 2850 (1), pp. 1-123 : 68-70

Liriomyza merga spec. nov.

Figs 144–147

Wing length 1.8–1.9mm (♂), 2.3–2.5mm (♀). Length of ultimate section of vein CuA 1 divided by penultimate section: 2.3–3.0. Eye height divided by gena height: 2.1–3.4. Scutum lightly dusted with pruinosity. Parafacial, orbital plate and thin cheek pronounced.

Chaetotaxy: Two ori (anterior ori sometimes reduced on one side), one or two ors. Acrostichal setulae in up to four rows, often three or two.

Colouration: Calypter margin and hairs yellow to white. Head light yellow with first flagellomere lemon yellow, clypeus yellow to brown, back of head and ocellar tubercle brown and posterolateral corner of frons with pale spot lateral to outer vertical bristle. Scutum with complete yellow lateral stripe; katatergite brown ventrally; anatergite brown, darker below scutellum and dorsum yellow lateral to scutellum. Anatergite with small oblique stripe in anteroventral corner; anepimeron with mottling and posterior margin brown; meron brown with dorsal margin yellow; ventral ¾ of katepisternum (not including base of bristle) and spot behind bristle brown. Legs yellow with base of coxae brown (widest on hind coxa), base of femora narrowly brown (widest on hind femur and sometimes vestigial on fore femur), hind femur with streaking along scraper, fore tibia sometimes brownish, mid tibia brownish (sometimes paler at base and apex), hind tibia dark brown medially, and tarsi brownish, becoming paler to base. Abdomen brown with posterior margin of tergites narrowly yellow and lateral margin broadly yellow.

Genitalia: Figs 144–147 . Surstylus narrowed apically and with one subapical spine. Swollen distal section of duct relatively short with base bulbous. Paraphallus rod-shaped, fused to basiphallus on right side. Hypophallus with base ill-defined and apex with long hairs. Mesophallus narrowed apically, approximately as long as high and partially fused to distiphallus. Distiphallus bifid with base darker and more stout, and with long, clear apical tubules with basolateral striations wrapping around tubule; base of distiphallus surrounded by internally spinulose collar. Ejaculatory apodeme with pileus ejaculatorius truncated and dark at ends; stem well-developed and blade broad, sometimes semicircular and with distal margin dark medially.

Variation: Male from Glenn Co. with wing length of 1.6mm, eye height divided by gena height 1.8, acrostichal setulae almost entirely absent, pleuron more extensively pigmented and distiphallus approximately ¾ as long.

Etymology. The specific epithet is Latin for “two pronged pitchfork”, referring to the shape of the phallus.

Host. Unknown; adult collected on Veratrum californicum (Melanthiaceae) .

Range. USA. California [Glenn, Mariposa, Placer], Montana, Utah, Washington.

Type material. Holotype, USA. Washington: Mt. Rainier, Paradise Park , viii.1917, A.L. Melander (1♂, USNM) ; Paratypes, USA. California: Glenn Co., Black Butte , 6500-7400’, 16.vi.1972, Veratrum californicum foliage, S.L. Szerlip (1♂, EMEC) , Mariposa Co., Yosemite Park, Glac [ier] P[oin]t R [oa]d, A.L. Melander, 6.vii.1947 (1♀, UCR) , 1.vii.1947 (1♀, CSCA) , Placer Co., E end Bear Val. , 1.vi.1964, P.H. Arnaud Jr. (1♂, CASC) , Montana: Glacier Park, Grinnell Lake , 24.vii.1935, A.L. Melander (1♀, CSCA) , Avalanche Lake , 14.vii.1935 (1♂ 1♀, USNM) , A.L. Melander (1♀, USNM) , Utah: L. Cottonwood Canyon , 8000’, 23.vi.1940, A.L. Melander (3♀, USNM, 2♀, CASC) , Washington: Mt. Rainier, Paradise Park , viii.1917, A.L. Melander (1♂ 1♀, USNM) .

Comments. Liriomyza merga is a relatively large, pale species with a greyish scutum, almost no pigment on the frons, sometimes only a single ori, and a large, bifid phallus with a basal collar, one pair of ventrobasal plates and laterobasal striations. A number of taxa have a similar phallus and can be confused for this species, including L. cunicularia , L. bella , L. parabella , L. tubula , L. elevata Spencer and L. splendens Spencer. Liriomyza bella and the new species L. parabella are most easily diagnosed because the scutum is yellow with dark stripes, L. cunicularia has a much larger and more robust phallus; all three of these species also lack a basal collar on the distiphallus. Liriomyza tubula always has two rows of acrostichal setulae, the outer vertical bristle touches the lateral brown spot, the first flagellomere is subquadrate with the dorsal margin partially brown, the parafacial/orbital plate is most pronounced anterodorsally, the face is sometimes brownish medially, the pleuron and femora are darker and the calypter margin is grey. Liriomyza elevata (Colorado) differs in having the first flagellomere orange to brown, the thorax and legs are much darker, the paraphallus is well developed, the basiphallus is flared laterally towards the apex and the distiphallus tubules are strongly bent dorsally at the midpoint. Liriomyza splendens (New York) also has an entirely pale calypter, but there are three ori, the outer vertical bristle is surrounded by brown, the femora are entirely light yellow, the ejaculatory apodeme is larger and darker, and the distiphallus is smoother with a basal collar.

Figures

FIGURES 144–151. Figs 144–147: Liriomyza merga spec. nov., male holotype genitalia; 144: external components, ventral; 145: phallus, ventral; 146: phallus, left lateral; 147: ejaculatory apodeme. Figs 148–151: L. cunicularia spec. nov., male genitalia; 148: external components, ventral; 149: phallus, ventral; 150: phallus, left lateral; 151: ejaculatory apodeme.