Phyllonorycter holodisci (Braun, 1939)

(Figs. 35–37)

Lithocolletis holodisci Braun 1939: 282 . Phyllonorycter holodisci (Braun) — Davis 1983: 10.

Leaf mine. An upper-surface blotch, becoming wrinkled when mature (Figs. 35–36). This species has been occasionally observed to form lower-surface mines in California.

Host. Rosaceae: Holodiscus discolor (Pursh) Maxim.

Distribution. Canada: BC; USA: CA, ID, OR, WA.

Review. The type specimen (Fig. 37) was reared from an upper-surface mine on Holodiscus discolor collected in California (Del Norte Co.) on 23 August 1936. Braun (1939) also collected mines in Washington (Clallam Co.) and Oregon (Lane Co.) but found them to be heavily parasitized and reared no further specimens. De Benedictis et al. (1990) collected mines in California (San Mateo Co.) in April and July but failed to rear adults. They implied that this species forms lower-surface mines, as was later stated by Gates et al. (2002). A collection of preserved leaf mines from California provided by D.L. Wagner consists primarily of upper-surface mines, but it does indeed include a few underside tentiform mines like those of other Phyllonorycter species (e.g., from Russell Tree Farm, Contra Costa Co., 6 July 1981). D.L. Wagner (pers. comm.) has reared adults from both mine types and believes they are conspecific. Mines found in Idaho (Kootenai Co., 27 September 2012, photographed by CSE; Figs. 35–36), Washington (Whatcom Co., 28 July 2016; Palmer 2016), and British Columbia (Vancouver Island, 10 August 2019; Mews 2019) were all on the upper leaf surface as described by Braun.