MOTHS OF UMATILLA NATIONAL WILDLIFE REFUGE: Results from 10 sites Sampled May 22-23, 2017 Dana Ross 1005 NW 30th Street Corvallis, OR 97330 (541) 758-3006 [email protected] SUMMARY Macro-moths were sampled from the Umatilla National Wildlife Refuge for a third time 22-23 May, 2017 as part of an ongoing pollinator inventory. Blacklight traps were deployed for a single night at ten sites representative of major plant communities in the McCormack and Paterson Units. A grand total of 331 specimens and 36 moth species were sampled. Of those, 17 species (47%) were documented from the refuge for the first time. In a somewhat larger geographical context, 21 species were recorded for the first (8), second (7) or third (6) time from Morrow County, Oregon while 4 species were documented for the first (1) or second (3) time from Benton County, Washington. INTRODUCTION National Wildlife Refuges protect important habitats for many plant and animal species. Refuge inventories have frequently included plants, birds and mammals, but insects - arguably the most abundant and species-rich group in any terrestrial habitat - have largely been ignored. Small size, high species richness and a lack of identification resources have all likely contributed to their being overlooked. Certain groups such as moths, however, can be easily and inexpensively sampled using light traps and can be identified by regional moth taxonomists. Once identified, many moth species can be tied to known larval hostplant species at a given site, placing both insect and plant within a larger ecological context. Moths along with butterflies belong to the insect Order Lepidoptera. The larvae (caterpillars) are consumers of enormous quantities of plant biomass and help to recycle plant nutrients back into the soil. Most adult moths feed on nocturnally available flower nectar and in doing so pollinate many flowering plant species. As egg, larva, pupa or adult, moths are an abundant and essential food resource for myriad species of birds (especially nestlings), bats, rodents, reptiles, amphibians and other insects. Moths are, therefore, an essential component of a healthy and productive ecosystem. Sampling that includes the physical collection of voucher specimens is a necessary as part of any meaningful insect inventory. Vouchers added to regional collections serve as indisputable evidence of a study’s findings and contribute to a greater knowledge about wing pattern and general morphological variability. When moth information (species, date, location, etc.) is data- based and combined with existing data sets it can lead to a more resolute understanding of each species range, distribution, flight period and relative abundance. These surveys add to a Umatilla NWR moth inventory initiated in July, 2015. Each refuge has a unique assemblage of insects where each species serves one or more specific ecological roles. Moths are a particularly species-rich group of insects yet remain largely unknown for most important wildlife areas including our national wildlife refuges. 1 METHODS A total of ten sample sites (Figures 1 & 2, Tables 1 & 2) were selected to capture macro-moth diversity across a variety of major habitat types within the combined McCormack (Morrow County, Oregon) and Paterson (Benton County, Washington) units of the Umatilla NWR. Sites included a variety of riparian forest, wetland and steppe communities over a seven mile distance. For consistency, most sites sampled where those that had been used previously with final trap locations determined on-site once each area was observed first-hand. When possible, traps were placed in locations not visible to the public from primary access roads. The sample period was chosen to coincide with the new moon, a time when interference from ambient moon light is minimal and the attractiveness of light traps is, therefore, optimal. While warm, calm nights with cloud cover are preferable to cold, rainy or windy nights, most moth species are capable of flying during adverse conditions, thus weather was considered somewhat secondary in importance to moon phase. For each site sampled, a 12 volt battery-powered light trap unit was run continuously over one full night (from dusk until dawn) with a 22 watt circular UV-blacklight bulb as a visual attractant. Moths hitting clear acrylic vanes mounted above the trap wouldthen fall down through a funnel and into a collection bucket charged with a fumigant (“No Pest Strip”) which quickly killed them. Light traps and associated batteries were retrieved early each following morning. Moth samples were placed in plastic baggies and labeled with location and date using a permanent marker pen. Samples were transferred to a refuge freezer until all refuge sampling was complete, then transported via ice chest to the lab in Corvallis and again frozen until they were processed. Processing entailed thawing moths on a large white sheet of paper and sorting/counting all macro-moths and some recognizable micro-moths to species. Identifications of most moths were straightforward and could be accomplished at that time. Less familiar moths were identified using the Oregon State Arthropod Collection (OSAC, Dept. of Zoology, Oregon State University, Corvallis) and web-based resources such as the PNW Moths (pnwmoths.biol.wwu.edu) and Moth Photographers Group (mothphotographersgroup.msstate.edu). The most difficult identifications required assistance from other moth experts. One or more voucher specimens for each moth species sampled were retained, mounted and labeled. Each first voucher specimen was deposited in the OSAC collection. Additional specimens were made available for refuge collections or displays. 2 Figure 1. Map of Umatilla NWR (Paterson Unit) moth trap 2017 1-5 locations. 3 Figure 2. Map of Umatilla NWR (McCormack Unit) moth trap 2017 6-10 locations. 4 Table 1. Umatilla NWR 2017 moth site GIS attributes I. Trap Code Habitat Date Sampled 2017-1 steppe 5/22/2017 2017-2 steppe with bitterbrush 5/22/2017 2017-3 sagebrush with lush forbs 5/22/2017 2017-4 seasonal wetland (willow) 5/22/2017 2017-5 riparian forest (cottonwood) 5/22/2017 2017-6 steppe & riparian forest edge 5/23/2017 2017-7 steppe/forest/corn circle 5/23/2017 2017-8 riparian forest (cottonwood/willow) 5/23/2017 2017-9 steppe, near river shoreline 5/23/2017 2017-10 steppe with bitterbrush 5/23/2017 Table 2. Umatilla NWR 2017 moth site GIS attributes II. Trap Code Refuge Unit UTM 11T (Easting / Northing) Elevation 2017-1 Paterson 306887 / 5087431 282 feet 2017-2 Paterson 305693 / 5088131 293 feet 2017-3 Paterson 305433 / 5088647 277 feet 2017-4 Paterson 304395 / 5087646 270 feet 2017-5 Paterson 304222 / 5087693 270 feet 2017-6 McCormack 299554 / 5088152 275 feet 2017-7 McCormack 299786 / 5086194 274 feet 2017-8 McCormack 297043 / 5084167 271 feet 2017-9 McCormack 296463 / 5083629 284 feet 2017-10 McCormack 295300 / 5083057 280 feet 5 Photo 1. Moth trap in steppe-bitterbrush habitat (Site 2017-2, Paterson Unit). 6 Photo 2. Blacklight trap in riparian forest (cottonwood) habitat (Site 2017-5, Paterson Unit). 7 Photo 3. Lush steppe habitat near riparian forest (near Site 2017-6, McCormack Unit). 8 Photo 4. Blacklight trap in steppe habitat near Columbia River (Site 2017-9, McCormack Unit). 9 RESULTS & DISCUSSION A total of 331 individual moths representing 36 species (Table 4) were sampled by all 10 moth traps combined. Of those, 47% (17 species) were sampled from the refuge for the first time. The average sample had 33 moths and 9 species. Individual samples ranged in size from 4 to 119 moths and included from 3 to 20 species (Table 3). The greatest moth abundance and number of species came from Site 2017-8 in the McCormack Unit within the understory of a willow-cottonwood riparian forest. Of the 20 species sampled, 3 species accounted for 71 of the 119 specimens. Site 2017-7 was located at the confluence of steppe, forest and cornfield habitats in the McCormack Unit and produced 49 individuals and 14 species. The smallest samples came from two sites dominated by bitterbrush and abundant cheat grass (Bromus tectorum). In the Paterson Unit, Site 2017-2 produced just 4 individuals and 3 moth species. Similarly, Site 2017-10 in the McCormack Unit trapped only 9 individuals representing 6 species. Significant distributional records (1st, 2nd or 3rd county records) were captured for moth species on 25 occasions and are noted in Table 4. Of those, 21 came from the McCormack Unit (Morrow County, Oregon) and 4 came from the Paterson Unit (Benton County, Washington). These can be placed in a larger Pacific Northwest context by viewing species distribution maps at the Pacific Northwest Moths website (http://pnwmoths.biol.wwu.edu/) and the Moth Photographers Group website (http://mothphotographersgroup.msstate.edu/) . Regionally uncommon to rare moths documented included Prorasea simalis (family Crambidae) and the noctuid moths Anarta fulgora and Schinia meadi. Table 3. Macro-moth abundance and species totals by trap. Trap Code (Refuge Unit) # of Moths # of Species 2017-1 (Paterson) 19 11 2017-2 (Paterson) 4 3 2017-3 (Paterson) 17 6 2017-4 (Paterson) 21 8 2017-5 (Paterson) 43 7 2017-6 (McCormack) 36 10 2017-7 (McCormack) 49 14 2017-8 (McCormack) 119 20 2017-9 (McCormack) 14 6 2017-10 (McCormack) 9 6 10 Table 4. Moth abundance by trap site (*Micro-moths. County Records: 1= 1st, 2= 2nd, 3= 3rd with Benton County, WA records in bold, and after those for Morrow Co., OR when 2 records exist). Moth Trap 2017-# Family Taxon 1 2 3 4 5 6 7 8 9 10 Total Prorasea