Calycomyza avira Eiseman & Lonsdale 2018, spec. nov.

Calycomyza avira spec. nov.

(Figs. 13, 15, 103, 262–267)

Holotype. CONNECTICUT: Redding, 31.v.1930, A.L. Melander (1♂, USNM).

Paratypes. CONNECTICUT: Redding, 1.vi.1929, A.L. Melander (1♂, USNM); MASSACHUSETTS: Berkshire Co., Sheffield, 9.vii.2014, em. by 28.vii.2014, C.S. Eiseman, ex Bidens frondosa, #CSE1225, CNC384838 (1♂); NEW YORK: Letchworth State Park, 13.vi.1963, pond margin, W.W. Wirth (1♂, CNC); NORTH CAROLINA: Durham Co., Durham, Grandale Drive, 14.vii.2017, em. 1–3.viii.2017, T.S. Feldman, ex Bidens, #CSE4047, CNC939843, CNC939844 (1♂ 1♀, CNC); WEST VIRGINIA: White Sulfur Springs, 16.vi.1970, G. Steyskal (1♂, USNM).

Additional material examined. MASSACHUSETTS: Plymouth Co., West Bridgewater, 41.995693, -71.055131, 15.viii.2013, em. by 5.v.2014, C.S. Eiseman, ex Bidens frondosa, #CSE1101, CNC384790 (1♀).

Etymology. The specific name compounds the Greek for ʺwithout” (a-) and the Latin for ʺwoman” (vira),

referring to the fact that females confidently attributed to this species could not be found for years following up to immediately before the publication of this paper.

Host. Asteraceae: Bidens frondosa L.

Leaf mine. (Fig. 103) A whitish, upper surface blotch with frass in scattered grains and small lumps. A short initial linear portion was evident in one of the North Carolina examples.

Puparium. (Fig. 15) Reddish-brown; formed outside the mine.

Distribution. USA: CT, MA, NC, NY, WV.

Adult description. Wing length 2.1–2.5mm (♂), 2.6mm (♀). Length of ultimate section of vein CuA1 divided by penultimate section: 2.1–2.3. Eye height divided by gena height: 4.5–5.3. First flagellomere rounded. Arista pubescent. Notum subshining.

Chaetotaxy: Two ori, two ors. Postocellar and ocellar setae well-developed. Three dorsocentral setae, third thin, less than half length of second dorsocentral. Six rows of acrostichal setulae. Two posteromedial setae on mid tibia.

Coloration: (Fig. 13) Setae dark brown. Head yellow with back of head, clypeus, palpus, ocellar tubercle and antenna dark brown; frons brownish in posterolateral corner, with faint stripe to base of posterior ors along frontoorbital plate that is slightly darker in tentatively associated female. Thorax dark brown with postpronotum (excluding dark anteromedial spot confluent with margin), notopleuron (excluding dark elongate sublateral spot) and small anterolateral spot behind suture yellow; posterodorsal corner of anepisternum yellow along suture. Calypter margin yellow and hairs brown. Haltere white. Legs and abdomen dark brown with fore knee yellow.

Genitalia: (Figs. 262–267) External components of Calycomyza type. Basiphallus composed of one pair of lateral sclerotized bars on distal half. Paraphallus absent. Hypophallus short and entirely membranous. Mesophallus short, slightly longer than wide, round and slightly compressed dorsoventrally; minute, dark medial sclerite present between mesophallus and distiphallus. Distiphallus short with tubules fused and folded, lateral margins sclerotized at stem-like base, short medial bowl with inner face heavily spinulose. CT males with bowl of distiphallus narrower and inner processes separate and not as strongly haired.

Comments. The genitalia of Calycomyza avira are most similar to those of C. verbenae (Hering), which is highly similar externally, and C. flavinotum, which is much larger and has one pair of large yellow posterolateral spots on the scutum. There are numerous other medium-sized species with dark calypter hairs and reduced pigment on the fronto-orbital plate not exceeding the level of the hind fronto-orbital. These occur primarily in the western United States, although C. eupatoriphaga spec. nov. extends into the northeast, and C. ambrosiae (Frick) extends into Tennessee and Florida to the south.

Since characters of the male genitalia are needed to adequately differentiate Calycomyza avira and C. verbenae, females have not been confidently attributed to either of these species in the present study unless collected alongside males. The single female listed above is also only tentatively allied to the new species since it was also reared from Massachusetts Bidens frondosa. As a result, Nearctic females examined from the USNM that could potentially belong to either one of these two species have been labeled as “ C. verbenae or related”. These include those specimens identified as C. verbenae by Frick (1956) from Maryland, Georgia, Mississippi and Florida. Exemplar males of the remaining C. verbenae identified by Frick have been dissected and confirmed except for the following: some New Mexico records represent C. enceliae Spencer; the Missouri and Texas males represent C. barbarensis; some Arizona, Illinois and Indiana records represent C. artemesiae marcida Spencer. Frick’s material from New York and Pennsylvania cannot be located, although these could be the Verbena -reared specimens in the USNM that do not have associated locality data.