Aciurina luminaria

[Aciurina luminaria galls] can be distinguished from [galls of] 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 ... 

Gall relatively large at maturity (7.24 mm mean latitudinal diameter), has a mostly rounded oblong to tapered teardrop shape and is covered uniformly in dense off-white cottony tomentum ... 

Biology. Aciurina luminaria is univoltine and has a life cycle and phenology similar to A. bigeloviae and A. trixa (Baine et al. 2023a; 2023b). Eggs are laid singly into the leaf bud of a distal plant stem. The gall forms at the oviposition site and the developing larva feeds on the tissue surrounding the central chamber of the gall. By fall, the gall reaches full size, and the larva reaches its final instar and chews to the outer layer of the gall to create a circular trap door. The larva ceases feeding and overwinters inside the gall, then pupates in the spring. Adults eclose in summer and push their way through the door to emerge from the gall and find a mate. The period of emergence from galls reared by these authors is May 29th – June 28th. The latest date of emergence in examined material from Utah is July 18th (gall collected 3 July 1966). 

Associated arthropods ... We also observed and reared a small number of Rhopalomyia (Diptera: Cecidomyiidae) hypergalls on the surface of galls collected in northwestern New Mexico. The hypergall system has been previously documented on both A. bigeloviae (Baine et al. 2023b) and A. trixa (Russo 2021), but whether the midge species is the same is unknown. 

Host plant. The known host plant is strictly Ericameria nauseosa subsp. ammophila L.C. Anderson, which was described from the San Luis Valley in Colorado (Anderson 2006). This plant is restricted to sandsheet and sand dune habitat and is known from southern Colorado (Anderson 2006) and here we add to its range northern New Mexico ... [T]he host plants of gall observations in Arizona are unidentified. 

Geographical range. Beyond the localities of the examined material above, we have confirmed the presence of this species in some locations reported by Dodson and George (1986): Great Sand Dunes National Monument, CO, and near the cities Grants and Gallup, NM. We are aware of a specimen collected from Kanab, UT (A. Norrbom, pers. comm. Aug 2024). We are also able to definitively identify from photos the distinctive tomentum and shape of this gall on iNaturalist. Thus, the following localities are added to our own observations to the range of A. luminaria from public user observations: Petrified Forest National Park, AZ (obs. no. 2848593 & 112933554); Porcupine Spring, AZ (170773584); Brown’s Canyon, CO (151317053); Nageezi, NM (141568708); Aztec, NM (151553769); White Sands National Park, NM (199614395); and Kodachrome Basin State Park, UT (57095918).

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 ... after the host leaves have dropped, so they are also associated with ... wintertime in the Southwest. The tradition of luminarias is common and adored in New Mexico, the type locality of this species.

Discovery of a new gall-inducing species, Aciurina luminaria (Insecta, Diptera, Tephritidae) via multi-trait integrative taxonomy