Liriomyza septentrionalis Sehgal

Lonsdale, Owen, 2011, The Liriomyza (Agromyzidae: Schizophora: Diptera) of California 2850, Zootaxa 2850 (1), pp. 1-123 : 95-98

Liriomyza septentrionalis Sehgal

Figs 2 , 214–217

Liriomyza septentrionalis Sehgal 1968: 70 . Spencer 1969: 184, 1981: 271; Spencer & Steyskal 1986: 122.

Fig. 2 . Wing length mm 1.5–2.7(♂), 2.3–3.5mm (♀). Length of ultimate section of vein CuA 1 divided by penultimate section: 1.7–1.9. Eye height divided by gena height: 4.2. Scutum shining.

Chaetotaxy: Two ori (sometimes one on one side), two ors. Acrostichal setulae in four rows.

Colouration: Calypter margin and hairs brown. First flagellomere usually entirely yellow, but sometimes lightly infuscated to slightly darker on anterior margin; posterolateral corner of frons variably dark, with dark region reaching nearly to base of outer vertical bristle or to base of inner vertical (if surrounded by brown, vertical bristles always with narrow yellow spot surrounding base); clypeus, ocellar triangle and back of head dark brown; ventral margin of gena with pale brownish band. Scutum with complete lateral yellow stripe; laterotergites light brown, becoming darker below scutellum. Pleuron dark brown with dorsal 1/5–1/4 of anepisternum and often katepisternum yellow. Legs dark brown with apex of femora and base of tibiae (narrowly) yellow. Abdomen dark with lateral margin of tergites yellow, with yellow margin broad and easily viewed dorsally on tergites 1–3.

Genitalia: Figs 214–217 . Epandrium without spine. Surstylus small and subtriangular with one long, thin, curved apical bristle. Basiphallus with dark bar on left ventroapical surface; base of distiphallus flanked by dark, scaled membrane that is often broken off or missing on one or both sides. Swollen apical section of duct short and with strong ventral curve. Hypophallus long-haired and fused to base of distiphallus. Mesophallus not distinct. Distiphallus very large and directed dorsally, with stout, curved basal section and large cup-like apical section; distal cup enclosing inner spines and one pair of thin, flat, dark medial process. Ejaculatory apodeme with pileus ejaculatorius dark and strongly produced laterally as domes with ends strongly produced; venter of bulb and broad base of stem well-sclerotized, blending into dark, thin duct; blade broad, becoming paler and annulated with minute striations apically.

Variation: Females with wing length of 4.1mm with higher colour contrast and distoventral surface of fore femur yellow. A minority of material slightly to significantly paler than above description, usually with distoventral surface of fore, and sometimes mid and hind femora yellowish to yellow. Some material from San Mateo, Monterey and Sagehen Counties differ as follows: only posterodorsal corner of anepisternum yellow; dorsal 1/3 of katepisternum and meron yellow; katatergite yellow; only base of fore coxa brown; tip of mid coxa yellow; fore femur only brown dorsobasally; apices of mid and hind femora more broadly yellow. Some material from Berkeley differ as follows: dorsal 1/3 of katepisternum yellow; anepisternum with broad yellow posterodorsal and smaller anteroventral spots; only base of fore and hind coxae brown; fore femur brown basally and dorsally mottled on basal 2/3; mid femur more widely yellow apically. Specimen from Sugarloaf Mountain differs as follows: anterior margin of first flagellomere dark yellow; ventral margin of gena yellow; pleuron yellow with ventral 2/3 of katepisternum and meron brown, anterior margin of anepimeron brown and anteroventral corner of anepisternum with oblique stripe; femora yellow with base narrowly brown; tibiae and tarsi light brown; abdomen more widely yellow.

Hosts. Poaceae — Bromus , Hordeum , Lolium .

Range. USA. California [widespread], Colorado. Canada. Alberta, British Columbia .

Type material. Holotype, CANADA. Alberta: Banff , 28.vi.1966, V. K. Sehgal (1♂, CNC).

Additional material examined. USA. California: 663♂ 947♀ 6? [ CASC, CSCA, EMEC, SBMN, UCD, UCR, USNM] .

Comments. Among the Californian fauna, the characteristic colour of the abdomen and the legs are very useful for separating this species from the remainder of the agromyzid fauna. Specimens with paler femora can be confused for Liriomyza langei , but the abdomen of that species is entirely dark and the first flagellomere is almost always darker apically. Outside of agricultural crops where pests such as L. sativae and L. langei can be abundant, L. septentrionalis is by far the commonly encountered species of Liriomyza in California. Californian adults have been collected “on week-old human feces”, the flowers of Daucus carota (Umbelliferae) , Lolium and the foliage of Pinus radiata .

Liriomyza septentrionalis is almost entirely indistinguishable from the Albertan species L. cordillerana Sehgal externally, with the latter only confidently diagnosed internally by a longer distiphallus with a broader, shallower, darker apical “cup” that reveals the dark medial processes, no lateral “scales” on the distiphallus, more extensive distal processes on the basiphallus and a bare surstylus.

Figures

FIGURES 1–3. 1: Liriomyza sativae Blanchard, female. Fig. 2: L. septentrionalis Sehgal, male. Fig. 3: L. nebulosa spec. nov, male holotype. Fig. 4: L. langei Frick, male.

FIGURES 214–217. Liriomyza septentrionalis Sehgal, male genitalia; 214: external components, ventral; 215: ejaculatory apodeme; 216: phallus, left lateral; 217: phallus, ventral.