Melanagromyza vanderlindeni Eiseman & Lonsdale 2019, spec. nov.
Creators: name: Eiseman, Charles S.
name: Lonsdale, Owen
Publisher: name: Zenodo
Year: 2019
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Agromyzidae
Melanagromyza
Melanagromyza vanderlindeni

description: Melanagromyza vanderlindeni spec. nov.
(Figs. 71–76)
Holotype. IOWA: Winneshiek Co., 27.ii.2017, em. 7–11.vi.2017, J. van der Linden, ex Eutrochium, #CSE3883, CNC940119 (1³).
Paratypes. Same data as holotype, CNC940116–940118 (3♀).
Etymology. This species is named in honor of John van der Linden, Iowa naturalist, who reared the type series and has made numerous other discoveries involving stem-feeding insects, a few of which are reported in this paper.
Host. Asteraceae: Eutrochium Raf.
Larval biology. Presumably an internal stem borer; adults emerged from dead stems collected in winter. J. van der Linden (in litt.) recalls finding externally visible mines on some of the stems, but these were likely made by Ophiomyia larvae.
Puparium. Formed within the stem.
Distribution. USA: IA.
Adult description. Wing length 2.7 mm (³), 2.3–2.7mm (♀). Length of ultimate section of vein CuA 1 divided by penultimate section: 0.7–0.8. Eye height divided by gena height: 3.7–5.6. Seen in profile, head and eye narrowing ventrally and bulging dorsally; orbital plate slightly prominent medially and anteriorly. First flagellomere small, rounded, hairs slightly longer on anterior margin. Frons slightly expanded at middle, making orbital plate sinuous; orbital plate approximately 1/5 width of frons. Ocellar triangle not well-defined anteriorly but appearing to almost attain anterior margin of frons. Lunule wider than high, with ventromedial groove. Face slightly curved anteriorly at venter, with slight medial carina. Clypeus U-shaped. Thorax with light pruinosity.
Chaetotaxy: Minimum of two ors and two ori (small female), with space between ori only slightly more than that between other setae; one female with two ors and three ori; male and one female with smaller medial ori on one side and male with three ors and three ori on other side. Orbital setulae erect to reclinate, in two to three scattered rows, outer row slightly exclinate. Eye densely setulose dorsomedially in male and small female, sparsely setulose dorsomedially in other females. Postvertical and ocellar setae thin, length subequal to ors. Two strong dorsocentral setae, anterior seta slightly shorter. Acrostichal seta absent. Acrostichal setulae in approximately 10 scattered rows. Mid tibia with two posteromedial setae.
Coloration: Setae black. Body dark brown; abdomen faintly blue metallic, sometimes with light green shine anteriorly; notum very weakly metallic, color barely visible except in bright light, varying from purple (small female) to blue; body paler brown along inner orbital plate, lunule, parafacial, center of face and gena, slightly paler medially on notopleuron, and sometimes paler on frontal vitta (excluding tubercle) and legs; outer orbital plate and ocellar triangle darker. Calypter margin and hairs yellow.
Genitalia: (Figs. 71–76) Epandrium with minute posteroventral spine on inner surface that is atrophied on one side; fully fused to surstylus. Surstylus very short, broad, anteriorly angled and distal margin nearly straight; inner surface with four rows of tubercle-like setae that narrow to two rows posteriorly. Cercus well-developed, inner ventrodistal setae thicker. Hypandrium subtriangular with apex produced as narrow apodeme and base very broadly rounded. Pregonite irregular and band-like with minutely setulose patch weakly attached to inner dorsally directed half. Phallophorus with base strongly constricted with venter weakly sclerotized; distal section ventrally swollen. Basiphallus short, V-shaped, weakly produced dorsomedially; narrowly separated from phallophorus, separated from mesophallus by slightly greater distance. Mesophallus pale, cylindrical, inserted ventromedially into distiphallus; base barely exceeding that of distiphallus. Rounded basal section of distiphallus broad, extending over mesophallus and with bilobed basal surface; one pair of short, narrow ventrolateral tubules on distiphallus flanking mesophallus; dorsal chamber of distiphallus slightly swollen subapically and constricted apically, enclosing thick, transverse, dorsal spinulose patch distal to high carina; distal section past mesophallus narrowing apically, with thick ventromedial plate that is widest medially, and with dorsomedial tubule that is relatively wide at apex and bulging dorsally at base. Stem of ejaculatory apodeme with long dark rib continuing onto pale, narrow blade; stem with long process to one side; base narrow, wider towards duct; sperm pump with dark transverse sclerotized ventral band with medial process extending to base of apodeme.
Comments. Using the key in Spencer & Steyskal (1986), this new species can be identified as Melanagromyza vernoniae Steyskal (Spencer & Steyskal 1986: Figs. 47, 48), with which it does indeed share a strong similarity, including a medially widened frons that slightly projects anteriorly, a dorsomedially setulose male frons, a pale calypter, two strong dorsocentrals and bluish metallic reflection (sometimes greenish in M. vernoniae). Externally, however, the new species differs as follows: all fronto-orbitals are evenly spaced (anterior ori not displaced anteriorly); the wing is slightly shorter (2.8–3.5 mm in M. vernoniae); the abdomen is faintly bluish (not green). The genitalia of the new species differ as follows: the surstylus is narrower and shorter with a shorter marginal cluster of tubercle-like setae; the apodeme of the hypandrium is much shorter (nearly as long as remainder of sclerite in M. vernoniae); the phallophorus is swollen ventrally (not cylindrical); the base of the mesophallus somewhat exceeds that of the distiphallus; the distiphallus is wider medially, higher dorsally with a slight swelling above the inner spinulose patch, the spinulose patch is thicker and resting on a high inner carina, the ventromedial plate of the distiphallus is longer, thicker and wider, and the dorsomedial tubule of the distiphallus is apically narrower and with a thick basal bulge.
description: Published as part of Eiseman, Charles S. & Lonsdale, Owen, 2019, New State and Host Records for Agromyzidae (Diptera) in the United States, with the Description of Ten New Species, pp. 1-39 in Zootaxa 4661 (1) on pages 4-5, DOI: 10.11646/zootaxa.4661.1.1, http://zenodo.org/record/3378418