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| Aciurina luminaria Baine, in Baine, White, Martinson et Martinson, 2024. |
Abstract
Integrative taxonomic practices that combine multiple lines of evidence for species delimitation greatly improve our understanding of intra- and inter-species variation and biodiversity. However, extended phenotypes remain underutilized despite their potential as a species-specific set of extracorporeal morphological and life history traits. Primarily relying on variations in wing patterns has caused taxonomic confusion in the genus Aciurina, which are gall-inducing flies on Asteraceae plants in western North America. However, species display distinct gall morphologies that can be crucial for species identification. Here we investigate a unique gall morphotype in New Mexico and Colorado that was previously described as a variant of that induced by Aciurina bigeloviae (Cockerell, 1890). Our analysis has discovered several consistent features that distinguish it from galls of A. bigeloviae. A comprehensive description of Aciurina luminaria Baine, sp. nov. and its gall is provided through integrative taxonomic study of gall morphology, host plant ecology, wing morphometrics, and reduced-representation genome sequencing.
Key words: Bigeloviae, candle, ddRAD, Ericameria, flame, marshmallow, nauseosa, rabbitbrush, tephritid, trixa, wing
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| Aciurina luminaria sp. nov. A holotype lateral habitus B allotype lateral habitus. Difference in eye color is a result of the age of mounted specimen C holotype dorsal habitus D allotype dorsal habitus E holotype head, anterior F holotype abdomen, dorsal G–H variation in dorsal abdomen color G mostly orange morph H dark morph. |
Aciurina luminaria Baine, sp. nov.
The Candle Flame Gall Tephritid
Diagnosis: This wing pattern of the adult A. luminaria can be distinguished most easily from both A. bigeloviae and A. trixa by the elongate hyaline spot in cell br, consistent dark brown region surrounding crossvein r-m, and lack of dark stripe in anal cell; it further from A. bigeloviae by lack of dark stripe in the postero-distal region of cell m and lack of medial dark stripe in cell cua1 (frequently present in A. trixa also). It differs from the similar-looking A. maculata (Cole, 1919) and A. lutea (Coquillett, 1899) by the hyaline cell bc and hyaline basal region of cell br. The extent of bright orange on the abdomen of many A. luminaria specimens also distinguishes it from A. maculata which has a more red abdomen, and from A. bigeloviae and A. trixa which frequently have a dark orange, brown, or black abdomen. Genitalia structures are highly similar to that of A. bigeloviae, except perhaps for the rounded tips of the prensisetae which differ from illustrations in Steyskal (1984). However, Steyskal describes A. bigeloviae (at the time synonymized with A. trixa and A. semilucida) as being highly variable in male terminalia characters, so this may or may not be reliably diagnostic. The gall can be distinguished from A. bigeloviae and A. maculata by the pointed, teardrop shape, and from all remaining galls in the genus by the thick layer of dense tomentum covering the surface (Fig. 2).
Etymology: The species epithet is a noun derived from the Spanish word for “light” which is specifically used in the southwest United States for small decorative lanterns traditionally displayed during the winter leading up to Christmas. We chose this epithet because the shape of this species’ gall is similar to that of a small flame on a candle, like those inside luminarias. Furthermore, this species’ galls are easiest to find when they are mature, and after the host leaves have dropped, so they are also associated with display in wintertime in the Southwest. The tradition of luminarias is common and adored in New Mexico, the type locality of this species. We elected to use the more widespread term luminaria over northern New Mexico regionally specific “farolito” because the species’ range extends into other regions in the West.
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| Galls of Aciurina luminaria and A. bigeloviae A immature A. luminaria galls B internal view of immature A. luminaria gall with early instar larva burrowing into the stem while gall develops C mature A. luminaria galls D internal view of mature A. luminaria gall with full-sized larval chamber E mature A. bigeloviae galls F internal view of A. bigeloviae gall with a mature larva in the larval chamber. Side by side comparison of A. bigeloviae (left) and A. luminaria (right) tomentum texture and uniformity G external view H internal view. |
Quinlyn Baine, Branden White, Vincent G. Martinson and Ellen O. Martinson. 2024. Discovery of A New Gall-inducing Species, Aciurina luminaria (Insecta, Diptera, Tephritidae) via multi-trait integrative taxonomy. ZooKeys. 1214: 217-236. DOI: doi.org/10.3897/zookeys.1214.130171
