Liriomyza ivorcutleri Eiseman & Lonsdale 2018, spec. nov.

Liriomyza ivorcutleri spec. nov.

(Figs. 31–32, 143, 293–298)

Holotype. IOWA: Howard Co., Hayden Prairie State Preserve, 15.vii.2015, em. 1.viii.2015, C.S. Eiseman, ex Silphium perfoliatum, #CSE1915, CNC654358 (1♂).

Etymology. This species is named for Ivor Cutler (1923–2006), Scottish recording artist, whose several entomologically themed compositions include one that begins, “I am a yellow fly.”

Host. Asteraceae: Silphium perfoliatum L.

Leaf mine. (Fig. 143) Whitish to greenish, soon turning brown; upper surface; entirely linear; frass mostly in strips along the sides.

Puparium. (Fig. 31) Yellow; formed outside the mine.

Distribution. USA: IA.

Adult description. Wing length 1.7mm (♂). Female unknown. Length of ultimate section of vein CuA1 divided by penultimate section: approximately 2.1 (wing curled). Eye height divided by gena height: approximately 4.2. First flagellomere small, rounded. Arista pubescent and relatively short and gracile with base thicker, approximately three times length of first flagellomere. Notum pruinose.

Chaetotaxy: Two ors, one ori. Ocellar and postvertical setae subequal to ors. Four dorsocentral setae, strongly decreasing in length anteriorly. Acrostichal setulae in two rows; few scattered intra-alar setulae around suture.

Coloration: (Fig. 32) Setae dark brown. Base color of body paler yellow than most congeners, being especially pale on antenna, pleuron and femora. Head yellow with ocellar tubercle brown, clypeus brownish anteromedially, and back of head dark brown with margins around ventral half yellow. Scutal spot dark brown with gray/bluish pruinosity; postpronotum and lateral margin of scutum with complete yellow stripe, excluding spot on postpronotum; posterior margin of scutum with complete yellow stripe that has one pair of narrow yellow emarginations anterior to posterior intra-alar, and with broad, shallow triangular emargination between dorsocentral rows that slightly exceed level of first dorsocentral. Scutellum with lateral dark brown spot. Mediotergite dark brown, anatergite brown with posterodorsal region yellowish, katatergite yellow with posteroventral corner brown. Pleuron mostly yellow with very small, faded brown anteroventral spot on anepisternum, anepimeron with small brown anterior stripe, meron brown ventrally, katepisternum with large brown ventral spot not reaching level of seta. Wing veins yellow. Calypter margin and hairs grayish. Haltere yellow. Legs yellow with base of coxae narrowly brown, and mid and hind tibia with slight brownish tint that is paler on mid leg. Tergites 1 and 6 with one pair of small, faint spots; tergites 2–5 with one pair of brown spots that are wider than long; epandrium dark brown.

Genitalia: (Figs. 293–298) Epandrium produced as triangular point ventrally with apical spine. Surstylus narrow apically, with one spine. Phallophorus small, narrowed ventrally. Basiphallus a Y-shaped dorsal plate with one pair of arms distolaterally; articulating with phallophorus via L-shaped basal extension. Hypophallus small and rod-like with apical hairs. Paraphallus narrow, band-like and strongly curved, forming inverted “U”. Distal section of ejaculatory duct swollen and pigmented. Mesophallus nearly twice as long as wide, with flared ventral suture continuing along surface of distiphallus; fused to distiphallus. Distiphallus with round cup-shaped base as long as mesophallus that is angled and open dorsally, out of which emerges one pair of wide membranous, fringed tubules that are more than twice length of distiphallus; ventrobasal surface of tubule shielded by small rounded plate. Ejaculatory apodeme dark and well-developed; sperm pump ventrally sclerotized with one pair of dark lateral bars at margins; base of duct sclerotized.

Comments. This species is similar in genitalic morphology to two California species— Liriomyza flavicola Spencer and L. nebulosa Lonsdale—neither of which has been reared. The former is similarly pale, but it sometimes has two ori, the paraphalli are absent and the tubules of the distiphallus are curved dorsally. The latter is much darker, has three ori, and the phallus is much longer. Using the Liriomyza key in Lonsdale (2011), the new species will key to L. bella Spencer, which has entirely yellow legs excluding the apical tarsomeres, and a very long, bifid distiphallus.

We have found similar leaf mines on Silphium perfoliatum, as well as on S. integrifolium Michx., S. laciniatum L., and S. terebinthinaceum Jacq., in Missouri, Ohio, Oklahoma, and Wisconsin. No agromyzid has previously been reported from Silphium, apart from our new record of Calycomyza platyptera (which forms blotch mines rather than linear) cited above.