Collections of Epiblema rudei Powell, 1975, (Tortricidae) in Utah

Abstract

In 2011 and 2013, MM collected several unknown moths during routine trapping for pest Tortricidae in a tree-fruit orchard in Utah, USA, near Utah Lake (Table 1, Fig. 1). The moths were collected in orange large plastic delta traps using Grapholita molesta pheromone lures (Pherocon OFM L2 12-week, Trécé, Adair, OK). In 2013, several of the specimens were sent to the Washington State Department of Agriculture, Olympia WA, for identification. They resembled Epiblema desertana (Zeller, 1875) and E. rudei Powell, 1975 based on wing patterns (Fig. 2), although neither species is recorded from Utah. Both species feed upon and form simple galls on the stems of Asteraceae, with E. desertana recorded from Euthamia graminifolia (L.) Salisb. in the eastern United States and Canada (Miller 1976) and E. rudei from Gutierrezia californica (DC.) Torr. & A. Gray in California (Powell 1975). Euthamia graminifolia and G. californica do not appear to be recorded from Utah, although E. occidentalis Nutt. is widespread there (Intermountain Regional Herbarium Network 2020) and G. sarothrae (Pursh) Britton & Rusby is a common and prominent shrub in the state (Welsh 1983, GBIF.org 2019). Moths were trapped again in spring 2014, and again in spring 2016 (Table 1). In October 2015, CL collected voluminous amounts of G. sarothrae from five locations in Utah (Fig. 1) and placed them in secure rearing chambers stored in a non-temperature-controlled workshop in Olympia, WA. Chambers were monitored several times per week between early April and early June, but no moths emerged. In late June we prepared to dispose of the dry and brittle plant material and discovered that eight moths had emerged from two of the collections, sometime between the second and fourth week in June, 2016 (Table 1). Based on comparison with genitalia (Fig. 3) figured in Powell (1975) and the abundance of a congeneric host plant in the collection area, we identified the moths as E. rudei. We also generated COI "barcode" sequences for four specimens (631-698 base pairs per sequence) and compared them with data in the BOLD systems and the NCBI databases (NCBI 1998, Ratnasingham and Hebert 2013). The identification engine on BOLD returned a 97.1–97.6 % similarity score with a single privately held specimen of E. rudei, with the next most similar sequences a series of E. desertana (~96% similarity). These scores are not supportive of a species match generally speaking (Hebert et al. 2003), although there was only a single specimen of E. rudei in the BOLD database and none in the NCBI database. Nonetheless, morphological and ecological data support the diagnosis of E. rudei.