Agromyza princei 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
Agromyza
Agromyza princei

description: Agromyza princei spec. nov.
(Figs. 1, 2, 34, 64–70)
Holotype. CONNECTICUT: Hartford Co., Windsor, Mt. St. Benedict Cemetery, 3.vi.2016, em. 16.iv.2017, C. S. Eiseman, ex Rubus occidentalis, #CSE3496, CNC939942 (³).
Etymology. This species is named for Prince (born Prince Rogers Nelson; 1958–2016), composer and performer of the song “Raspberry Beret,” who died shortly before the larva was discovered mining a leaf of black raspberry.
Host. Rosaceae: Rubus occidentalis L.
Leaf mine. (Fig. 34) Initially linear, gradually widening to an irregular blotch. Frass is initially deposited in two rows of discrete but closely spaced grains; later it is scattered more irregularly, with some larger particles toward the end.
Puparium. (Fig. 2) Reddish-brown; formed outside the mine.
Distribution. USA: CT.
Adult description. Wing length 2.1 mm (³). Female unknown. Length of ultimate section of vein CuA 1 divided by penultimate section: 0.8. Eye height divided by gena height: 6.7. First flagellomere small, rounded; anterodorsal margin with ovate tuft of hairs about half height of segment. Face with shallow carina. Thorax subshining.
Chaetotaxy: Two ors, one ori, subequal in length. Postvertical and ocellar setae subequal to fronto-orbitals. One row of orbital setulae. Frons with a few relatively long anteromedial setulae adjoining lunule that are approximately 1/3 length of ori. Four dorsocentral setae, slightly decreasing in length anteriorly. Acrostichal seta strong, subequal to fourth dorsocentral. Acrostichal setulae in four irregular rows. Mid tibia without posteromedial setae.
Coloration: (Fig. 1) Setae dark brown with brown shine. Body mostly dark brown with halter white; antenna paler brown; thorax with faint grayish pruinosity that is densest on notum where it has faint bluish and coppery reflections; legs paler than thorax, apices of femora with light yellow spot that is largest on fore leg, being almost as long as wide; tibiae paler than femora with fore tibia almost yellowish; tarsi paler than tibiae, palest on fore legs. Calypter margin white, hairs light brown.
Genitalia: (Figs. 64–70) Epandrium broad, shallow; inner-distal margin fused to small, rounded surstylus, which has two tubercle-like setae. Cercus large. Hypandrium well-developed, subtriangular with short pointed apical apodeme; inner lobe large, inner margin relatively straight, distal margin weaker, emarginated and with two or three minute setae; arms basal to inner lobe reduced. Pregonite with ventral rounded lobe with small setae on inner surface; base produced as long curved arm that fuses to phallapodeme. Phallophorus strongly atrophied on right side, reduced to basal ring; produced on left side with distal surface minutely haired. Basiphallus divided between two sclerites fused to left distal margin of phallophorus; left sclerite weak, becoming weaker, more irregularly sclerotized and outwardly produced apically, base indistinguishable from phallophorus; right sclerite broad and irregular at base, wrapping around right surface of shaft apically. Hypophallus shallow, membranous; very small sclerotized point below distiphallus perhaps originating from this structure. Ejaculatory duct with elongate, strongly swollen / spindle-shaped section that narrows before mesophallus. Mesophallus dark, narrow, ventral to duct, U-shaped with base extending ventromedially towards basiphallus as weak, irregularly sclerotized stripe; short membranous space separating mesophallus and distiphallus. Paraphallus absent. Distiphallus dark, almost ring-shaped with venter incomplete and posterolateral margin recessed; approximately as long as mesophallus. Ejaculatory apodeme with stem short and stout, blade short, broad and rounded with clear margin, and base strongly atrophied; sperm pump small, clear.
Comments. Agromyza princei is well-supported as sister to A. masculina Sehgal—keying to that species in Spencer & Steyskal (1986) —reared from Rosa in New York (Scheffer & Lonsdale 2018) and also known from Alberta and Utah. The two are externally quite similar, with perceived differences minor and possibly only due to differing states of preservation or sampling bias: wing length 2.1 mm in A. princei and 2.6–2.7 mm in A. masculina (larger than the 2.5 mm stated in the original description of this species, based on examination of the types); thorax of A. masculina with pruinosity slightly sparser and browner. The genitalia are especially similar in the structure of the epandrium and phallus, but the following differences in A. masculina (Spencer & Steyskal 1986: Figs. 449–451) allow for confident differentiation: phallophorus narrower; left arm of basiphallus narrower with fewer irregular fragmented patches along margin; floating sclerotized point below base of distiphallus absent; mesophallus narrower and with a thicker, darker, more sinuous basal stripe; distiphallus longer and narrower.
Our other collections of agromyzid larvae on Rubus have only yielded adults of Agromyza vockerothi Spencer (Eiseman & Lonsdale 2018). The mine of that species does not widen to a blotch, and the frass does not form two distinct rows. Also, whereas the larva of A. princei pupated by 6 June and did not emerge as an adult until the following spring, larvae of A. vockerothi collected from late May (North Carolina) to late June (Massachusetts) had a pupal period ranging from three weeks to nearly three months, with only the pupa of a larva collected in October overwintering before adult emergence.
Frick (1959) reported Agromyza idaeiana Hardy (as A. spiraeae Kaltenbach) from Rubus spp. including R. occidentalis in the USA. That species does form linear-blotch mines, but in the mines on Geum and Potentilla from which we have reared it, the frass again does not form two distinct rows. Ellis (2018) reports the frass in two rows, but in the illustrated examples, the particles are not closely spaced throughout the linear portion as they are in the single known mine of A. princei.
One other Rosaceae feeder that occurs in North America, Agromyza sulfuriceps Strobl, is recorded from Rubus spp. in Europe; it likewise forms a linear-blotch, but the transition to a blotch is abrupt rather than gradual, and the linear portion “contains much, amorphous frass that sometimes seems to fill the entire corridor”; “[i]n the blotch the frass is in black strings and coarse lumps” (Ellis 2018). Both A. idaeiana and A. sulfuriceps are bivoltine (Eiseman & Lonsdale 2018; Ellis 2018).
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 2-3, DOI: 10.11646/zootaxa.4661.1.1, http://zenodo.org/record/3378418