Liriomyza taraxaci Hering

Eiseman, Charles S., Lonsdale, Owen, Linden, John Van Der, Feldman, Tracy S. & Palmer, Michael W., 2021, Thirteen new species of Agromyzidae (Diptera) from the United States, with new host and distribution records for 32 additional species, Zootaxa 4931 (1), pp. 1-68 : 31

publication ID	https://doi.org/ 10.11646/zootaxa.4931.1.1
publication LSID	lsid:zoobank.org:pub:88CF2B0D-E02B-46E1-9F52-1B95F717FC8F
DOI	https://doi.org/10.5281/zenodo.4678645
persistent identifier	https://treatment.plazi.org/id/0395A00B-703C-EB52-2A99-FE9761706017
treatment provided by	Plazi
scientific name	Liriomyza taraxaci Hering
status

Treatment

Liriomyza taraxaci Hering View in CoL

( Fig. 79 View FIGURES 73–86 )

Material examined. VERMONT: Washington Co., Montpelier, North Branch River Park (44.283214, -72.571026), 21.vii.2018, em. 9.viii.2018, C.S. Eiseman & J.A. Blyth, ex Taraxacum officinale , # CSE4914 , GoogleMaps CNC1643637 View Materials (1♀) ; ONTARIO: Renfrew Co ., Pembroke, Pansy Patch Park , 45.821464, -77.112117, 7.vii.2018, em. 20.vii.2018, C.S. Eiseman & J.A. Blyth, ex Taraxacum officinale , # CSE4811 , GoogleMaps CNC1643630 View Materials GoogleMaps (1♁).

Tentatively identified material. NORTH CAROLINA: Scotland Co., Laurinburg, St. Andrews University , 10.iv.2017, em. 6.v.2018, T . S. Feldman, ex Krigia virginica , # CSE4499 , CNC1144028 View Materials (1♀) .

Photographed mines. MARYLAND: Baltimore City Co., Herring Run Watershed, 19.vi.2017, T. Wilson, Taraxacum ? officinale, BG 1228804; MINNESOTA: Fillmore Co., Rushford, Magelssen Bluff Park, 24.vi.2019, C.S. Eiseman, Lactuca canadensis [vacated mines]; NORTH CAROLINA: Wake Co., Lake Crabtree County Park, 9.v.2019, T.S. Feldman, Krigia dandelion [vacated mines], BG 1660443.

Hosts. Asteraceae : [ Cichorium intybus L., Krigia dandelion Nutt., K. * virginica (L.) Willd.], Lactuca biennis (Moench) Fernald , L. canadensis L. , L. sativa L., [ L. serriola L.], Taraxacum officinale F.H.Wigg. (Eiseman & Lonsdale 2019) .

Leaf mine. ( Fig. 79 View FIGURES 73–86 ) The mines on Krigia are linear throughout, necessarily contorted in the small leaves, with frass in grains, irregular particles, and short strips along the sides. Mines of L. taraxaci s.l. on Lactuca and Taraxacum rapidly widen to form blotches , and larvae are frequently gregarious on Lactuca ( Eiseman & Lonsdale 2018, 2019).

Puparium. Yellow to yellow-orange; formed outside the mine.

Phenology and voltinism. The tentatively identified female was collected as a larva in early April and the adult emerged the following spring. Otherwise, adults we have reared of Liriomyza taraxaci s.l. have emerged 11–25 days after the larval collection dates, indicating the species is at least bivoltine. These have included larvae collected in North Carolina on 28 April and 10 June, and in Massachusetts on 6 July, 12 July, and 21 August ( Eiseman & Lonsdale 2018, 2019). In Alberta, a larva collected in August apparently emerged as an adult the following spring, unless the error in the reported emergence date was in the month rather than the year (collected 18.viii.1974, emerged 5.v.1974, according to Lonsdale (2017a)).

Distribution. USA: AK, IL, MA, [MD, MN], NC, NY, *VT, WA, [WI]; Canada: AB, BC, MB, NB, ON, QC, SK, YT; Europe (Eiseman & Lonsdale 2019).

Comments. The only previous record of an agromyzid from Krigia is that of Ophiomyia beckeri (Hendel) , also in North Carolina (Eiseman et al. 2019). The year-long diapause observed in this rearing of Liriomyza cf. taraxaci from Krigia is highly unusual for Liriomyza in our experience. Due to this, along with the entirely linear leaf mines, the rearing of males to confirm the identity of the Krigia feeders is desirable.

The Taraxacum officinale -reared specimens in collections CSE4811 and CSE4914 reveal previously unappreciated variation in Liriomyza taraxaci , as both have a very narrow yellow line along the posterior margin of the scutum. This character will key it to L. cracentis in Lonsdale (2017a), but they differ in that the posterior yellow margin is much narrower (almost indistinguishable) and doesn’t narrowly extend anteriorly at two points to touch the bases of the posterior pair of dorsocentrals. Furthermore, the bases of the femora are brown dorsally and the fore femur has brownish streaking, as seen in L. taraxaci . We have stated that L. taraxaci is a relatively variable species, so this additional small variation is not entirely surprising if it is conspecific. Material discussed in Lonsdale (2017a) was re-examined, and this line is present in some specimens collected in Ottawa.