﻿New records of Nitidulidae (Nitidulidae, Coleoptera) species in Canada, Ontario, and Manitoba

﻿Abstract Nitidulidae trapping performed from 2018 to 2021 to characterize flight behaviors of potential vectors of the oak wilt pathogen yielded three new species records for Canada, six new species records for Ontario, and three new species records for Manitoba. The new records for Canada include Carpophilus (Ecnomorphus) corticinus reported from Ontario, C. (Myothorax) nepos reported from Ontario and Manitoba, and Glischrochilus (Librodor) obtusus reported from Ontario. In addition, the following species are first recorded in Ontario: Carpophilus (Ecnomorphus) antiquus, C. (Megacarpolus) sayi, Stelidotacoenosa; and also in Manitoba: Carpophilus (Megacarpolus) lugubris and Cychramusadustus. Collection data is provided for the two provinces and national records.


Introduction
The family Nitidulidae occurs globally with at least 4,500 species, of which, 173 species are found in North America (Habeck 2002;Marske and Ivie 2003). Also known as sap beetles or picnic beetles, Nitidulidae feed on flowers, fruits, fungi, stored products, decaying and fermenting plant tissues, carrion, and other insects. Feeding on fermenting sugars of fruits and vegetation is most common. Feeding by the beetles introduces fungi and bacteria to damaged plant tissues, resulting in further decay and fermentation. This appetite attracts the beetles of several Nitidulidae genera to the fruit-like smell of fungal mats produced by the oak wilt pathogen, Bretziella fagacearum (T.W. Bretz) J Hunt, which is an invasive species of fungus affecting oak trees (Quercus spp.) (Downie and Arnett 1996). Nitidulids become contaminated with fungal spores when they visit oak wilt mats. New infections occur when contaminated beetles leave the oak wilt mats and fly to fresh wounds on healthy oak trees, spreading the disease across the landscape (Jagemann et al. 2018). Identifying beetle species associated with movement of the fungus is important for establishing management criteria.
Oak wilt has been killing oak trees in the United States for more than half a century, spreading to 24 states and residing within 1 km of Canada on Belle Island, Michigan (Juzwik et al. 2008;USDA-FS 2019). Oak trees are susceptible to this fungus with some species dying within weeks of the initial infection. Oak wilt can infect neighboring trees through root-to-root contact (Bruhn et al. 1991), however transmission by nitidulids is considered more concerning because of the potential for transmission over greater distances and the formation of many new infection epicenters (DiGirolomo et al. 2020).
Overland spread of oak wilt by nitidulid beetles can be reduced by avoiding oak wounding when nitidulids are most active. A multi-year study of Nitidulidae beetle flight behavior was carried out at 21 localities in the following three Canadian provinces, Manitoba, Ontario, and New Brunswick. The study also aimed to describe the diversity of nitidulids that could be involved in oak wilt transmission. Beetles were collected using flight interruption traps. In total, there were 49 nitidulid species collected across the three provinces with three new records in Manitoba, six new records in Ontario, and three new records for Canada from Ontario and Manitoba. No new records are reported for New Brunswick.

Materials and methods
Traps were deployed at 14 localities in Ontario, four in Manitoba, and three in New Brunswick (Fig. 1). Flight intercept traps were installed in Manitoba in or near Winnipeg. These four localities are in the Interlake Plain and Lake Manitoba ecoregions (Smith et al. 1998). Both ecoregions experience short, warm summers and long, cold winters with slightly warmer temperatures in the Lake Manitoba Ecoregion. Deciduous and coniferous forest remain but large areas have been cleared for agriculture. Localities included an airport and three provincial parks. Bur oak (Quercus macrocarpa Michx.) is the only oak species that occurs in these ecoregions (Farrar 1995).
All New Brunswick localities were in the Grand Lake Lowlands ( Fig. 1; Province of New Brunswick 2007). This ecoregion has a longer growing season and warmer summer temperatures than the rest of the province due the presence of the Grand Lake. The area is dominated by coniferous and mixed forests, but deciduous forests do occur. Trees are present in 70% of the ecoregion. Northern red oak (Quercus rubra L.) and bur oak are found in New Brunswick (Farrar 1995).
Ontario localities were in three ecoregions classified as 5E, 6E and 7E (Fig. 1). Six localities were in Ecoregion 5E, the Georgina Bay Ecoregion (Crins et. al 2009). Localities were mixed hardwood forests, a residential property with oak trees, and a forest edge next to a field. The climate of 5E is cool-temperate and humid. The area is dominated by mixed, deciduous, and coniferous forests typical of the Great lakes-St Lawrence Forest region. Predominant tree species are red pine (Pinus resinosa Sol. Ex Aiton), eastern white pine (Pinus strobus L.), eastern hemlock (Tsuga canadensis (L.) Carrière), yellow birch (Betulae alleghansiensis Britt.), maple (Acer spp.) and oak (northern red oak, bur oak). To the south is the Lake Simcoe-Rideau Ecoregion (i.e., Ecoregion 6E) which extends from the eastern shore of Lake Huron to the Ottawa River (Crins et al. 2009). Study localities within Ecoregion 6E included a mixed hardwood forest, a park containing hardwoods, and an oak plantation. The climate is mild and moist. More than half of the ecoregion has been converted to agriculture fields. The remaining treed areas are deciduous, coniferous, and mixed forests characteristic of the Great Lakes-St Lawrence Forest region. Oak species that may be found in Ecoregion 6E include northern red oak, bur oak, black oak (Quercus velutina Lam.), white oak (Q. alba L.), swamp white oak (Q. bicolor Willd.), and chinquapin oak (Q. muelhlenbergii Engelm.) (Farrar 1995).
Ecoregion 7E, the Lake Erie-Lake Ontario Ecoregion, is the most southerly area of Ontario (Crins et al. 2009). It incorporates shorelines from lakes Huron, Erie, and Ontario. The entire Carolinian forest region, dominated by beech, maple, black walnut, hickory, and oak forests, occurs here. This area is considered unique to Canada because it is the northern edge of the deciduous forest in North America, which does not occur elsewhere in Canada. The area experiences cool winters and long, hot, humid summers. Nearly 80% of the area has been converted to agriculture fields. Deciduous forests cover approximately 10% of the ecoregion. In addition to the oak species found in Ecoregion 6E, 7E may contain northern pin (Quercus ellipsoidalis E.J. Hill), Shumard (Q. shumardii Buckl.), dwarf Chinquapin (Q. prinoides Willd.) and swamp pin oak (Q. palustris Muenchh.) (Farrar 1995). Ecoregion 7E is warmer than 6E and 5E and has a longer average growing season. The three ecoregions share a similar range in precipitation. Study localities were a mixed hardwood forest and two plantations in urban areas.
Flying beetles were collected using four types of traps; wind-oriented funnel traps, 12-unit Lindgren funnel traps, 12-unit modified Lindgren funnel traps, and 5-unit Synergy multitraps (Synergy Semiochemical Corp. Delta, BC). Wind-oriented funnel traps are also referred to as PVC pipe traps and wind-oriented pipe traps (Dowd et al. 1992;DiGirolomo et al. 2020). Three traps were placed at least 10 m apart at 16 localities in Ontario and Manitoba. Traps were hung from poles approximately 1.0-1.5 m in height from the ground and placed within 10 m of a red oak (Quercus rubra) or a bur oak (Q. macrocarpa). Wind-oriented traps were solely used at 14 localities and 12-unit Lindgren traps used at two localities. At four localities near Sault Ste Marie, Ontario and Fredericton, New Brunswick, five of each, wind-oriented funnel, Synergy multitrap, Lindgren funnel, and modified Lindgren funnel, were placed 20 m apart in hardwood stands containing Quercus species. At one additional site in New Brunswick, the same design was used except no Synergy multitraps were deployed. These traps were also hung from poles, at the same height from the ground.
The wind-oriented funnel traps (Dowd et al. 1992) included a collection chamber with insecticidal strips (19.2% Diclovos, "Ortho Home Defence Max No-Pest Insecticide Strip") and a lure chamber containing fermenting flour dough plus commercial lure for Carpophilus (Megacarpolus) sayi Parsons, 1943 andColopterus truncatus (Randall, 1938) beetles (Great Lakes IPM, Vestaburg MI) (Jagemann et al. 2018). The yeast dough was replaced every week, the pheromone lures every four weeks, and the insecticidal strips each month. Lindgren-funnel traps (Lindgren 1983), modified Lindgren traps (Miller et al. 2013), and Synergy multitraps were set up and maintained with the same lures and schedule as the wind-oriented funnel traps. Lures and baits were hung inside the top funnel for modified traps and outside for non-modified traps (Miller et al. 2013). The funnel cups were filled with a saltwater solution with several drops of dish detergent and replaced after every collection (Webster et al. 2012). Collections were made weekly from March to October. Samples were stored at -20 °C until they could be sorted and identified.
Specimens were initially sorted and identified by technicians (Sylvia Greifenhagen, Ontario Forest Research Institute (OFRI) and DD, Invasive Species Centre) and lead research scientist (SR, OFRI), later identifications were confirmed by Cucujoidea specialist (Gareth Powell, Florida State Collection of Arthropods). All specimens are deposited at OFRI in Sault Ste Marie, Ontario, except for New Brunswick collections which are held at the Atlantic Forestry Centre collection in Fredericton, NB. The generic attribution of the Carpophilus species was used after the papers by Kirejtshuk (2008Kirejtshuk ( , 2018. Information on the number of specimens recorded and collections where specimens were deposited is included in parentheses () after each record.
All species are listed with their current known distribution in Canada (Bousquet et al. 2013;Webster et al. 2016Webster et al. , 2022, using abbreviations from the province/territory. New records for Ontario, Manitoba are indicated in bold. The following abbreviations are used in the text and
Distribution in Canada. ON (new Canadian record).

Carpophilus (Megacarpolus) lugubris Murray, 1864
Notes. This species is recorded for much of central and western Canada from British Columbia to Saskatchewan and Ontario (Bousquet et al. 2013). Here, we report Carpophilus (Megacarpolus) lugubris for the first time in Manitoba from three localities in 2019, 2020, and 2021. This species being found in Manitoba was not unexpected since it is present in the bordering provinces of Saskatchewan and Ontario. Downie and Arnett (1996) (Bousquet et al. 2013).
New records.

Stelidota coenosa Erichson, 1843
Notes. This is the first record of Stelidota coenosa for Ontario. It was collected at one locality in the province in 2021. The species was first reported from boletus mushrooms in a Pinus banksiana forest in Northumberland Co., New Brunswick by Webster et al. (2016). It has also been recorded from several states along the eastern United States from New York to Florida (Parsons 1943). Stelidota coenosa was collected as far west as Wisconsin, south to Arizona and can be found in subtropical and tropical areas of Central and South America (Galford et al. 1991

Discussion
In 2013, Bousquet et al. (2013) reported 99 species of Nitidulidae from Canada. This included 45 species from Manitoba and 63 from Ontario. In addition, three Palaearctic species were recently recorded in Canada, the first one from New Brunswick (Webster et al. 2016), the second one from Prince Edward Island (Webster et al. 2022), and the third one from Ontario . Brunke et al. (2019) suggested that the total number of Nitidulidae species in Canada is even higher. They used an analysis of BOLD barcode index numbers to estimate that as many as 12 Nitidulidae species from Canada have not been described or reported.  (Kirejtshuk 2008;Kirejtshuk and Mantič 2015) or consideration of this group as a separate family (Cline et al. 2014;Smith 2022).
The new records fill gaps in our knowledge of these species' distributions. Of the new species found in Ontario, Carpophilus (Megacarpolus) sayi was the most frequently reported species with records at 13 of 14 survey localities. Carpophilus (Myothorax) nepos also appears widespread, being reported at numerous localities throughout southern Ontario (i.e., ecoregions 6 and 7) and in Manitoba.
Four new records occurred only in southern Ontario (i.e., ecoregions 6E, 7E), indicating that more surveys in this region could increase our knowledge of Nitidulidae diversity in Canada. One reason may be that part of this region contains the northernmost extent of the deciduous forest type, sometimes called the Carolinian Forest Region or the Deciduous Forest Region (Crins et al. 2009). The diversity of flora and fauna is greater here than in other parts of Canada. This region is warmer and has a longer growing season than the rest of Ontario because of its proximity to three large lakes and its southern position (Crins et al. 2009). In addition, further surveying in Manitoba is needed to clarify if Carpophilus (Megacarpolus) lugubris, C. (Myothorax) nepos, and Cychramus adustus occur outside the greater Winnipeg area. No new records were made for New Brunswick, suggesting that recent efforts to more fully describe the beetle diversity of this province have been reasonably complete (Majka et al. 2008;Webster et al. 2016).
The new species recorded in this study have been collected from fungi or sap flows and some are known to transmit fungal spores and fragments of mycelia (Price 2003). New detections of mycetophagous beetles in Canada are important, further elucidating how fungi and fungal diseases are spread across Canada's treed landscapes. Especially species of Carpophilus, Glischrochilus, Cychramus, Stelidota, and others that have been found at oak wilt mats or other fungal structures (Price 2003).