Liriomyza zinniae Spencer

(Figs 23, 24, 53, 54)

Material examined. ARIZONA: Maricopa Co., Tonto National Forest, east of Tortilla Flat, 6.iii.2017, em. 18– 22.iii.2017, C.S. Eiseman, ex Bahiopsis parishii, #CSE3235, CNC940430, CNC940431 (1³ 1♀); same collec- tion data, em. 19.iii.2017, #CSE3251, CNC940429 (1♀); CALIFORNIA: Imperial Co., Ocotillo, Shell Canyon, 7.iii.2017, em. 17–18.iii.2017, C.S. Eiseman, ex Encelia farinosa, #CSE3217, CNC940100, CNC940101 (2³); Palo Verde, Milpitas Wash Rd. (33.39528, -114.91337), 6.iii.2017, em. 18.iii.2017, C.S. Eiseman, ex Encelia farinosa, #CSE3234, CNC940075 (1³) ; TEXAS: Edwards Co., 1.3 mi NW of Camp Wood, 16.iii.2017, em. 9.iv.2017, C.S. Eiseman, ex Viguiera dentata, #CSE3429, CNC941273 (1³).

Tentatively identified material. CALIFORNIA: San Diego Co., Hawk Canyon, 11.iii.2017, em. 21.iii.2017, C.S. Eiseman, ex Geraea canescens, #CSE3256, CNC940066 (1♀) ; TEXAS: Edwards Co., 1.3 mi NW of Camp Wood, 16.iii.2017, em. 23.iii.2017, C.S. Eiseman, ex Verbesina virginica, #CSE3284, CNC941274 (1♀) .

Hosts. Asteraceae: Ambrosia psilostachya DC., * Bahiopsis parishii (Greene) E.E. Schill. & Panero, Calendula L., Encelia californica Nutt., E. * farinosa A. Gray ex Torr., Heterotheca grandiflora Nutt., * Viguiera dentata (Cav.) Spreng., Zinnia elegans Jacq. (Spencer 1981; Lonsdale 2011). Our tentatively identified females were reared from Geraea canescens Torr. & A. Gray and Verbesina virginica L.

Leaf mine. (Figs. 53, 54) Upper surface; greenish to whitish; entirely linear, with black frass in alternating strips (sometimes beaded or separated into closely spaced grains).

Puparium. (Fig. 24) Brown (yellow in one instance); formed within the leaf, in a roughly circular blister on the lower surface.

Distribution. USA: AZ, CA, * TX.

Comments. The pupation mode of this species has not been reported previously. Although the habit of forming an upper surface mine and then pupating just beneath the lower epidermis is common in Ophiomyia and Phytomyza, it is highly unusual in Liriomyza . It is also often, though not universally, exhibited by L. trifoliearum Spencer (Eiseman & Lonsdale 2018) and L. trixivora (this paper). We found all three species in a harsh desert environment where pupating in this way would seem to be a useful adaptation; a larva dropping to the ground may have difficulty locating a pupation site where it will be safe from heat and desiccation.

Although males are needed for identification of this species, we list the specimens from Geraea and Verbesina here because they were reared from brown puparia in blisters on the lower leaf surface like those formed by L. zinniae . Both host plants are in the tribe Heliantheae, which includes all of L. zinniae ’s known hosts except for Calendula (Calenduleae) and Heterotheca (Astereae) . The Verbesina specimen was also collected within 100m or so of the Viguiera dentata mines from which a male was reared.