Phytomyza thalictrivora Spencer

(Fig. 210)

Material examined. MASSACHUSETTS: Berkshire Co., Savoy, 1.vi.2013, em. 11.iii.2014, C.S. Eiseman, ex Thalictrum pubescens, #CSE1000, CNC384793 (1♀) .

Hosts. Ranunculaceae: Thalictrum * pubescens Pursh, T. venulosum Trel.

Leaf mine. (Fig. 210) Upper surface, greenish-white; probably entirely linear, but contorted to form an irregular secondary blotch. Frass is in scattered grains and irregular particles. The larva exits through a slit in the lower epidermis.

Puparium. Oval, orange-brown; at the time of collection it was attached to the underside of a leaflet adjacent to the mined one.

Distribution. USA: FL?, *MA; Canada: AB.

Comments. While known here from a single female, a number of characters allow for it to be identified as Phytomyza thalictrivora, including a relatively large first flagellomere, a broad, subshining orbital plate, characteristically gracile fronto-orbitals and only two rows of acrostichal setulae. This species was only previously known from the Albertan holotype [deposited in CNC and examined here] and a single tentatively identified female from northern Florida (Spencer & Stegmaier 1973). The type was collected from leaf mines on June 10, and the two adults (both males) emerged 15 days later (Spencer 1969). Our specimen was collected as a puparium on June 1 and the adult did not emerge until the following year. Occasional females exhibiting a long pupal diapause have also been observed in Aulagromyza orbitalis (Melander) (Spencer 1969) and (perhaps) Agromyza idaeiana Hardy (this paper; see Agromyza sp. 6).