Asphondylia undetermined

Dorchin, Netta, Joy, Jeffrey B., Hilke, Lukas K., Wise, Michael J. & Abrahamson, Warren G., 2015, Taxonomy and phylogeny of the Asphondylia species (Diptera: Cecidomyiidae) of North American goldenrods: challenging morphology, complex host associations, and cryptic speciation, Zoological Journal of the Linnean Society 174 (2), pp. 265-304 : 288

OTHER ASPHONDYLIA SPECIES ON GOLDENRODS

Aggregate bud galls that resemble those of A. monacha on S. juncea and S. erecta are known from several other goldenrod species, including S. patula , S. odora , and an undetermined Solidago species from Florida, based on material in the National Museum of Natural History, Washington, D.C. (USNM). Populations that are associated with S. sempervirens in Maine and Massachusetts ( Fig. 5 ), and with S. bicolor in Virginia ( Fig. 6 ), were studied in detail in the present work, and al- though we did not find morphological differences between them and A. monacha , our molecular analysis suggests that they belong to at least two undescribed species. These species are not described here because additional molecular data are needed in order to determine their boundaries and host associations. Their galls are locally common and appear similar in structure to those of A. monacha , although some galls on S. sempervirens develop in lateral rather than apical buds (C. Eiseman, pers. comm.). Galls are composed of numerous individual units, each with a single central chamber surrounded by several short leaves that are aggregated together to form a spherical structure on apical buds. Adult midges emerged from S. sempervirens from mid-August to mid-September, and from S. bicolor from early September to mid-October. Like other Asphondylia galls from goldenrods, these are also commonly attacked by the inquiline Youngomyia podophyllae and by several parasitoid Hymenoptera species. One individual from a rosette gall on S. uliginosa is also included in the sempervirens / bicolor clade, whereas another individual from this host grouped with A. monacha , suggesting that S. uliginosa is used by two different species.

Leaf snap galls were observed once during this study on S. nemoralis , but we were unable to rear adults from them or to characterize them with molecular tools. Similar galls may be found on other Solidago hosts but the identity of the species that induce them requires further study. Similarly, small rosette galls that resemble those of A. rosulata sp. nov. were observed by R.J. Gagné (pers. comm.) on Solidago tortifolia Elliott, 1823 in Maryland in late October, but the identity of the gall inducer is currently unknown.

Asphondylia johnsoni Felt (1908) has been described from an unknown species of Solidago and an unknown gall collected in Lansdowne, PA, USA, and is separated from A. monacha based on differences in adult colour, which is hardly a reliable character. The type we examined and Felt’s more detailed description of the male and pupa do not offer conclusive taxonomic information ( Felt, 1916). Without a known host and gall, it is impossible to determine whether A. johnsoni is a distinct species or to verify its identity through future collections. We therefore assign this species to nomina dubia.

Figures

Figures 1–6. Asphondylia bud galls: 1, 2, Asphondylia monacha spring galls on Solidago altissima sprouts; 3, Asphondylia monacha summer-generation gall on Solidago juncea; 4, Asphondylia monacha summer-generation gall on Solidago erecta; 5, Asphondylia sp. gall on Solidago sempervirens (photo: Charley Eiseman); 6, Asphondylia sp. gall on Solidago bicolor.