Agromyza arundinariae, Eiseman & Lonsdale & Feldman, 2019

Eiseman, Charles S., Lonsdale, Owen & Feldman, Tracy S., 2019, Nine new species of Agromyzidae from North Carolina, USA, with new host and distribution records for additional species, Zootaxa 4571 (3), pp. 301-333 : 303-304

Agromyza arundinariae spec. nov.

( Figs. 1–2 , 26–27 , 50–56 )

Holotype. NORTH CAROLINA: Moore Co., Aberdeen, Aberdeen Lake Park , 2.vi.2017, T.S. Feldman, ex Arundinaria tecta , em. 24.vi.2017, # CSE3852 , CNC939834 (1♂).

Tentatively identified material. NORTH CAROLINA: Scotland Co. , Laurinburg, St. Andrews University, 23.vi.2015, em. 7.vii.2015, T.S. Feldman, ex Arundinaria tecta , # CSE2005 , CNC564621 , CNC564622 (1♀ (unemerged, macerated and stored in glycerin) 1 puparium) .

Etymology. The specific epithet is derived from the host genus name, Arundinaria Michx.

Host. Poaceae : Arundinaria tecta (Walter) Muhl.

Leaf mine. ( Figs. 26–27 ) The greenish mine begins with a cluster of oviposition punctures in the distal half of the leaf, within a few mm of the margin. Two or more larvae feed together, forming a gradually widening mine that initially proceeds distally, then reverses direction and may reach the base of the leaf. The frass is mostly liquidy and indistinct, with a few scattered, discrete, blackish grains.

Puparium. ( Fig. 2 ) Dark reddish-brown; formed outside the mine.

Distribution. USA: NC.

Adult description. Wing length 2.6mm (♂). Female only tentatively associated due to similarity of leaf mine; unemerged and in poor condition, but visible features do not disagree with those of the male. Costa extending to M 1. Length of ultimate section of vein M 4 divided by penultimate section: 0.6. Eye height divided by gena height: 10.7. First flagellomere rounded, distal margin with slightly longer hairs that include a small, round whitish medial tuft (visible anteriorly). Ocellar triangle restricted to tubercle. Thorax with light pruinosity.

Chaetotaxy: Two ors, two ori, decreasing in length anteriorly. Few minute setulae on anteromedial margin of frons. Postvertical seta approximately as long as posterior ori; ocellar seta shorter, nearly as long as anterior ori. Four dorsocentrals, with only posterior two setae well-developed; anterior two setae thin and positioned close to second postsuturally; second seta almost as long as first seta, third approximately? length of second seta, fourth almost setula-like. Acrostichal seta strong, as long as second dorsocentral. Ten rows of acrostichal setulae. Mid tibia with two strong posteromedial setae.

Coloration: ( Fig. 1 ) Setae black. Body dark brown; wing veins yellowish, especially to base; halter white.

Genitalia: ( Figs. 50–56 ) Epandrium broadly rounded, shallow, fused to surstylus. Surstylus darkly pigmented, small, slightly lobate anterodistally; distal margin setose, and with irregular basal to medial cluster of small, rounded tubercle-like setae. Cercus long, finger-like. Hypandrium stout, inner-margin weakly sclerotized, basal lobe relatively broad, long, and with two minute setae near straight inner margin; apex pointed, with narrowing apodeme as long as inner lobe. Postgonite lobate with cluster of nine minute inner-medial setulae; with long, curved band-like process basally that meets phallapodeme; basal process densely and minutely spinulose on basal half. Phallophorus with short basal wall, and long dorsal wall that fuses to right sclerite of basiphallus. Distal third of basiphallus very dark with subtriangular apical section strongly incurved; bases nearly meeting dorsally past phallophorus; left sclerite with ventrally curving process at base. Hypophallus small, weakly sclerotized. Distal section of phallus typical of most grass-feeding Agromyza , with mesophallus and distiphallus fused into long, capsule-like structure with base sinuate (seen laterally) and ejaculatory duct inserted into wide ventrobasal fissure; apex weakly and minutely tuberculate, slightly expanded when viewed laterally; distal section relatively long, making composite structure as long as basiphallus, with ventral suture bordering long, narrow tear-drop shaped plate; seen ventrally, distal section past basiphallus with narrow parallel-sided base before swollen, rounded apex; distal margin produced backwards as short, weak dorsal plate. Ejaculatory apodeme with wide asymmetrical base, short stem that grades onto well-developed and apically clear blade; stem and blade with offset medial “rib”; sperm pump large, clear.

Comments. This new species differs from most Agromyza in being entirely dark, including the marginal hairs on the calypter, but excluding the margin of the calypter itself and the halter. There is also a small, round apical tuft of hairs of the first flagellomere and there are two strong posteromedial setae on the mid tibia. Externally, it is not readily differentiated from many other similar eastern grass-feeders, especially A. parilis Spencer (see Spencer & Steyskal (1986: Figs. 426, 427)), requiring male dissection. The distiphallus is distinct when viewed ventrally in that it has a narrow parallel-sided section before a swollen, rounded apex, and the incurved apices of the basiphallus are especially dark.

This is the first record of an agromyzid from the bamboo genus Arundinaria s.s., along with two additional new species we describe later in this paper, Cerodontha (Poemyza) arundinariella and C. (P.) saintandrewsensis . The Palearctic species C. (P.) bisetiorbita (Sasakawa) has been recorded from Arundinaria pygmaea var. glabra (Makino) Ohwi ( Sasakawa 1955, 1961), a synonym of Pleioblastus fortunei (Van Houtte) Nakai.

Figures

FIGURES 1–6. FIGURES 1–2. Agromyza arundinariae spec. nov.; 1: male; 2: puparia. FIGURES 3–4: Agromyza indistincta spec. nov.; 3: female; 4: empty puparia. FIGURE 5: Ophiomyia beckeri (Hendel), male. FIGURE 6: Ophiomyia sp. 2, empty puparium in leaf midrib.

FIGURES 26–32. leaf mines; 26: Agromyza arundinariae spec. nov. on Arundinaria tecta; 27: same; 28: A. indistincta spec. nov. on Dichanthelium; 29: Ophiomyia beckeri (Hendel) on Sonchus; 30: Ophiomyia sp. 1 on Hypochaeris chillensis, lower leaf surface; 31: same, upper leaf surface; 32: Ophiomyia sp. 2 on Pyrrhopappus carolinianus.

FIGURES 50–56. Agromyza arundinariae spec. nov., male genitalia; 50: external genitalia, ventral; 51: external genitalia, posterior; 52: postgonite; 53: hypandrium; 54: ejaculatory apodeme; 55: phallus, ventral; 56: phallus, left lateral.