Monoxia undefined-3

Monoxia sp. 3 (Figs. 116–117, 170) Collected specimen. CALIFORNIA: San Diego Co., Wind Canyon, 11.iii.2017, C.S. Eiseman, on Isocoma acradenia, # CSE3274 (1 adult, MLBM). Host. Asteraceae: Isocoma acradenia (Greene) Greene. Biology. A single adult was found on an Isocoma acradenia plant with empty leaf mines that were generally consistent with Monoxia mines we have found on other hosts (Figs. 116–117). Most were confined to the upper leaf surface, although one in a small, narrow leaf was full-depth. Each mine had an entry hole in the upper epidermis at its basal end, and a few round to elongate fecal pellets were scattered either within the mine or on the leaf surface outside this hole. Notes. S.M. Clark (in litt.) suggested that this beetle might be Monoxia beebei Blake, a species with which he is not familiar; the specimen matches many (but not all) of the published characters. Monoxia beebei was described from Santa Inez Island (Baja California), where the vegetation was dominated by Amaranthus watsonii Standl. and Atriplex barclayana (Benth.) D.Dietr. (Amaranthaceae), and it was presumed that one or both of these was the host plant (Blake 1937). This is the first report of Isocoma as an apparent larval host of a Monoxia species, but three species have been caught as adults on Isocoma: M. apicalis Blake on I. menziesii (Hook. & Arn.) G.L. Nesom; M. schizonycha Blake on I. menziesii var. vernonioides (Nutt.) G.L. Nesom; and M. sordida on I. veneta (Kunth) Greene (Clark et al. 2004).