Phytomyza cf. aesculi Eiseman & Lonsdale

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 : 32-33

Phytomyza cf. aesculi Eiseman & Lonsdale

( Fig. 81 )

Material examined. VIRGINIA: Radford, Wildwood Park , 3.v.2017, em. 8–11.iv.2018, N. V . Kent, ex Aesculus flava , # CSE4400 , CNC1135662–1135664 (3♀) .

Hosts. The type series of Phytomyza aesculi was reared from Sapindaceae : Aesculus glabra Willd. ( Eiseman & Lonsdale 2018) . The Virginia specimens were reared from A. flava Sol. , and mines have also been found on A. pavia L. and A. sylvatica W.Bartram.

Leaf mine. ( Fig. 81 ) Upper-surface; mines associated with the type series were described as “linear, gradually widening from 0.3 mm to 2–3 mm; whitish, with liquidy frass forming a broad, green central band, and with black- ish particles scattered within this.” The mines on Aesculus flava are initially narrowly linear with frass in closely spaced grains along the sides, but then rather quickly widen to an elongate blotch ~ 4.5 mm wide, in which the frass is scattered at random. The completed mine is thus shorter and more compact than the mines on A. glabra . On both hosts, there are often multiple mines per leaflet.

Puparium. Yellowish-brown to reddish-brown; on A. flava , frequently formed in the exit slit at the end of the mine, or adhering to the upper leaf surface nearby.

Phenology and voltinism. Phytomyza aesculi is univoltine, with larvae feeding in spring and adults emerging the following spring. The type series was collected as larvae in central Ohio between 6 and 11 May. A photo on iNaturalist shows larvae in St. Louis , Missouri on 24 April; photos on BugGuide. net show puparia in Radford , Virginia as early as 1 May, and we have found mines as early as 26 March in North Carolina .

Distribution. USA: OH; see Comments.

Comments. Confirmed specimens of Phytomyza aesculi are only known from USA: OH; leaf mines on Aesculus glabra and undetermined Aesculus spp. matching those of the type series have been found in IA, KS, MN, MO, and Canada: ON. Some mines on A. pavia and A. sylvatica from AL, AR, GA, NC, and SC are long and narrow like those from OH, while others become blotchy like those from which the VA specimens were reared, as do those found on A. glabra in PA. It is possible that there is a single Phytomyza species on Aesculus with somewhat variable leaf mine morphology, but the VA females differ from the type series of P. aesculi in having the face darker, the venter of the lunule and the region around the antennal bases blackish, and the apices of the mid and hind femora are dark. More reared males will be needed to clarify the situation.

Figures

FIGURES 73–86. Mines of Phytomyzinae on host plants: 73: Liriomyza blechi Spencer on Ruellia carolinensis; 74: Liriomyza cf. cracentis Lonsdale on Ageratina altissima; 75: L. euphorbivora Eiseman & Lonsdale, spec. nov. on Euphorbia marginata; 76: L. hypopolymnia Eiseman & Lonsdale, spec. nov. on Polymnia canadensis, upper surface; 77: same, lower surface; 78: L. orilliensis on Nabalus sp.; 79: L. cf. taraxaci Hering on Krigia virginica; 80: L. trifolii (Burgess) on Mecardonia acuminata; 81: Phytomyza cf. aesculi Eiseman & Lonsdale on Aesculus flava; 82: P. flavilonicera Eiseman & Lonsdale, spec. nov. on Lonicera sempervirens; 83: same; 84: P. notopleuralis Spencer on Cornus sericea; 85: P. thermarum (Griffiths) on Erigeron pulchellus; 86: P. triostevena Eiseman & Lonsdale, spec. nov. on Triosteum sp.