Calycomyza menthae Spencer

Calycomyza menthae Spencer

(Fig. 114)

Material examined. MASSACHUSETTS: Hampshire Co., Pelham, 88 Arnold Rd., 30.v.2014, em. 17– 30.vi.2014, C.S. Eiseman, ex Monarda didyma, #CSE1128, CNC384863–384876 (7♂ 7♀); NORTH CAROLINA: Durham Co., Durham, Pelham Rd., 21.v.2016, em. 3.vi.2016, T.S. Feldman, ex Hedeoma hispida, #CSE2539, CNC634978 (1♂); OKLAHOMA: Payne Co., Mehan, 36.014339° N, -96.996744° W, 20.iv.2017, em. 7.v.2017, M.W. Palmer, ex Monarda fistulosa, #CSE3736, CNC939889 (1♂); VERMONT: Chittenden Co., Williston, Mud Pond, 28.viii.2016, em. iv.2017, C.S. Eiseman, ex Lycopus uniflorus, #CSE3566, CNC940122 (1♂).

Tentatively identified material. MASSACHUSETTS: Hampden Co., Westfield, 12.viii.2014, em. 24.viii– 2.ix.2014, C.S. Eiseman, ex Lycopus uniflorus, #CSE1356, CNC384833, CNC384834 (2♀); Middlesex Co., Townsend, 42.68888526, -71.75159779, 19.vii.2017, em. 4.viii.2017, C.S. Eiseman, ex Lycopus uniflorus, #CSE4068, CNC939732 (1♀); OREGON: Lane Co., Blue River, 20.vii.2017, em. 8.viii.2017, M.W. Palmer, ex Prunella vulgaris, #CSE4262, CNC939939 (1♀).

Hosts. Lamiaceae: * Hedeoma hispida Pursh, * Lycopus uniflorus Michx., Mentha arvensis L., Monarda * didyma L., M. fistulosa L. (Spencer 1969). Spencer & Steyskal (1986) recorded the following additional hosts based on leaf mines from California and Florida where adults have not been found: Hyptis mutabilis (A. Rich.) Briq., Monarda punctata L., Monardella odoratissima Benth., and Ocimum L. Spencer (1969) tentatively attributed a leaf mine on Agastache nepetoides (L.) Kuntze to this species. Our female reared from Prunella vulgaris L. is consistent with Calycomyza menthae, as are the leaf mines on this host, but males would be needed to be certain of the identification. This is the first record of any Calycomyza from Prunella. We have found likely mines of C. menthae on Mentha canadensis L. and M. spicata L. in Massachusetts. A leaf mine on Pycnanthemum Michx. photographed in Maryland (Wilson 2013) may also represent C. menthae; this is not a known host for any agromyzid.

Leaf mine. (Fig. 114) Initially a narrow brown line, expanding to a messy, brownish blotch with clean, whitish margins here and there. Feeding lines like those of Nemorimyza posticata were visible in some examples. In the small leaves of Hedeoma, the mine occupies the entire leaf surface.

Puparium. Yellowish-brown to pale reddish-brown; formed outside the mine.

Distribution. USA: *MA, *NC, *OK, *VT; Canada: AB (Sehgal 1971), ON. The records of California and Florida (Spencer & Steyskal 1986) are based only on leaf mines. Our tentatively identified female reared from Prunella was collected in Oregon, and we have seen probable Calycomyza menthae mines on Monarda (including photographs posted to www.BugGuide.net) in CT, IA, MN, MO, and WI.

Comments. The only other Lamiaceae-feeding Calycomyza recorded from North America is C. hyptidis Spencer, which forms a characteristic star-shaped blotch with the frass all deposited in the center. It is not known to occur north of Florida. Although the host and distribution records based on leaf mines noted above may well all represent C. menthae, male specimens are needed to confirm them.