Moths of the Malheur National Wildlife Refuge
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MOTHS OF CONBOY LAKE NATIONAL WILDLIFE REFUGE: Results from 15 sites sampled July 7-9, 2018 November 2018 Dana Ross (Corvallis, Oregon) [email protected] The findings and conclusions in this report are those of the author and do not necessarily represent the views of the U.S. Fish and Wildlife Service. 1 SUMMARY Nocturnal moths were sampled from Conboy Lake National Wildlife Refuge in Klickitat County, Washington on the nights of July 8-10, 2018 as part of an ongoing moth inventory. Blacklight traps were deployed for a single night at 15 sites representative of plant communities throughout the refuge and captured a total of 1,226 individual macro-moths representing 132 moth species and an additional 23 species of micro-moths. Of those, 63 species were recorded on the refuge for the first time and 35 species represented just the first (11), second (9) or third (15) known Klickitat County occurrences. A grand total of 308 species of nocturnal moths have now been documented at Conboy Lake NWR. The April, early May, June and September time periods have yet to be sampled and will continue to add many more species to the refuge total. 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 biodiversity 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 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 moth 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 moth voucher specimens is necessary as part of any meaningful 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 precise understanding of each species range, distribution, flight period and relative abundance. Moths are a particularly species-rich insect group that remains largely unknown for most important wildlife areas, including our national wildlife refuges. Prior to this visit, Conboy Lake NWR had been sampled over three separate time periods: August 28-30, 2014, July 26-28, 2016 and May 20-21, 2017. The early July sampling reported here makes a unique contribution during a peak period of high moth diversity. 2 METHODS A total of 15 sites were sampled using blackight traps to capture nocturnal moths by targeting a variety of plant communities and habitat types across a broad portion of the refuge. Sample sites were representative of quaking aspen, ponderosa pine, mixed conifer, Oregon white oak, bitterbrush and wet and dry prairie habitats. (Figure 1, Tables 1-2, Photos 1-4). Sites were selected based on a Conboy Lake NWR habitat map and the author’s knowledge of the area. The loss of two previous sites (Sites #1 & #17) that contained bitterbrush – an important moth hostplant - required that a new site (#19) be chosen to document moths associated with that plant species. Similarly, the functional loss of an emergent marsh site (#7) required the establishment of Site #18. 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 fall down through a funnel and into a collection bucket charged with a fumigant (“No Pest Strip”) which quickly dispatched them. The sample period was chosen to coincide with the new moon portion of the lunar cycle, a time when interference from ambient moon light is minimal and the use of light traps is most effective. 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 secondary in importance to moon phase. Samples from traps were collected early the following morning, placed in plastic baggies and labeled with location and date using a permanent marker. Samples were then transferred to a freezer until all refuge sampling was finished for the given sample period. After transfer to the lab in Corvallis, samples were placed again in a freezer until they could be processed. Processing entailed thawing moths on a large white sheet of paper and sorting/counting all macro-moths to species. Some of the more recognizable micro-moth species were also retained. Identifications of most moths were determined immediately. 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 PNW Moths (pnwmoths.biol.wwu.edu) and Moth Photographers Group (mothphotographersgroup.msstate.edu). The most difficult identifications required assistance from other moth experts such as Dr. Paul Hammond of Philomath, Oregon. 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 select specimens were kept for a Conboy Lake NWR headquarters display collection. 3 Figure 1. Map of Conboy Lake NWR moth trap locations sampled in 2018. 4 Table 1. GIS Attributes 1 – 2018 moth sample sites. Site # Trap Code Habitat Type Date Sampled 2 Upland Meadow 1 Upland Meadow 7/8/2018 3 Aspen 1 Aspen 7/8/2018 4 Oak 1 Oregon White Oak 7/8/2018 5 Mixed Conifer 1 Mixed Conifer 7/8/2018 6 Wet Meadow 1 Wet Meadow 7/9/2018 8 Upland Wet Meadow Mix 1 Upland & Wet Meadow 7/9/2018 9 Upland Meadow 2 Upland Meadow 7/10/2018 10 Aspen 2 Aspen 7/9/2018 11 Mixed Aspen-Conifer 1 Mixed Aspen-Conifer 7/9/2018 13 Mixed Conifer 2 Mixed Conifer 7/10/2018 14 Ponderosa 2 Ponderosa 7/10/2018 15 Oak 2 Oregon White Oak 7/8/2018 16 Conifer 3 Mixed Conifer 7/9/2018 18 Emergent Marsh 2 Emergent Marsh/Wet Meadow 7/10/2018 19 Bitterbrush-Shrub Mix 1 Bitterbrush-Upland Shrub Mix 7/10/2018 Table 2. GIS Attributes 2 – 2018 moth sample sites. GPS Coordinates (10T) Site # Easting Northing Elevation (feet) 2 625446 5088181 1840 3 625825 5087223 1895 4 628080 5087541 1875 5 629917 5088673 1940 6 629629 5093316 1820 8 631566 5092658 1825 9 632517 5091345 1825 10 632322 5091134 1835 11 631954 5091968 1825 13 635001 5093756 1900 14 633773 5091012 1960 15 631860 5090258 1880 16 628165 5091449 1850 18 629989 5093419 1820 19 628483 5091487 1835 5 Photo 1. Blacklight trap in aspen understory habitat (Site #3). 6 Photo 2. Blacklight trap in wet meadow habitat (Site #6). 7 Photo 3. Blacklight trap in conifer understory habitat (Site 16). 8 Photo 4 (and Cover Photo). Blacklight trap in emergent marsh/wet meadow habitat (Site 19). 9 RESULTS & DISCUSSION A total of 1,226 individual macro-moths representing 132 species were sampled from 15 refuge moth sites combined during the July 8-10, 2018 sample period (Table 4). Additionally, 23 micro-moth species (families Crambidae, Geometridae and Pyralidae) were also noted, although some have not been identified beyond the family level and none were formally counted (simply marked as “present” within a given sample). As a result, this study added 63 new taxa to the refuge moth checklist and added 35 Klickitat County macro-moth species distribution records for the first (11), second (9) or third (15) time. Trap samples ranged in size from 5 to 190 individual macro-moths and included from 3 to 54 species (Table 3). The greatest numbers of individual moths and moth species were sampled from Site 4/Oak 1 (190 individuals; 54 species) and Site 15/Oak 2 (180 individuals; 49 species). The fewest were sampled from Site 18/Emergent Marsh 2 (5 individuals; 3 species) and Site 9/Upland Meadow (11 individuals; 5 species). The most abundant moths sampled were the erebid Hemeroplanis historialis (75 individuals across 9 sites) and the two geometrids Hesperumia latipennis (69 individuals across 8 sites) and Sericosema juturnaria (54 individuals across 8 sites). A total of 42 moth species (32%) were represented by just one individual for all samples combined. Two new trap sites were added. Site 18/Emergent Marsh 2 was the only site sampled of that plant community type and was the one location where the extremely rare noctuid moth Hypocoena inquinita was recorded. Its documentation at Conboy Lake NWR is just the second record for the state of Washington. Site 19/Bitterbrush-Shrub Mix 1 replaced Site 17/Ponderosa 3 post-burn, which had replaced Site 1/Ponderosa 1 post-burn, the latter two sites having been chosen for their bitterbrush component. The Site 19 sample uniquely included the crambid micro-moth Pyrausta subsequalis, a new species for the refuge.