The flat bark beetles (Coleoptera, Silvanidae, Cucujidae, Laemophloeidae) of Atlantic Canada

Eighteen species of flat bark beetles are now known in Atlantic Canada, 10 in New Brunswick, 17 in Nova Scotia, four on Prince Edward Island, six on insular Newfoundland, and one in Labrador. Twenty-three new provincial records are reported and nine species, Uleiota debilis (LeConte), Uleiota dubius (Fabricius), Nausibius clavicornis (Kugelann), Ahasverus advena (Waltl), Cryptolestes pusillus (Schönherr), Cryptolestes turcicus (Grouvelle), Charaphloeus convexulus (LeConte), Charaphloeus species nr. adustus, and Placonotus zimmermanni (LeConte) are newly recorded in the region, one of which C. sp. nr. adustus, is newly recorded in Canada. Eight are cosmopolitan species introduced to the region and North America, nine are native Nearctic species, and one, Pediacus fuscus Erichson, is Holarctic. All the introduced species except for one Silvanus bidentatus (Fabricius), a saproxylic species are found on various stored products, whereas all the native species are saproxylic. Ahasverus longulus (Blatchley) is removed from the species list of New Brunswick and Charaphloeus adustus (LeConte) is removed from the species list of Nova Scotia. One tropical Asian species, Cryptamorpha desjardinsi (Guérin-Méneville), has been intercepted in the region in imported produce, but is not established. A substantial proportion (44%) of the fauna is comprised of introduced species, almost all of which are synanthropic, associated with various dried stored products. Th e island faunas of Prince Edward Island, Cape Breton Island, and insular Newfoundland are diminished in comparison to the mainland fauna, that of Prince Edward Island being exceptionally so in comparison to other saproxylic groups found there. Of the ten native species, four can be categorized as “apparently rare” (i.e., comprising ≤ 0.005% of specimens examined from the region). It is possible that the apparent scarcity of these species is related to the long history of forest management in Atlantic Canada. Further research on saproxylic faunas in the region is urged to help determine the impact that forest practices may have had and to seek measures which might lessen or ameliorate such impacts. RESEARCH ARTICLE Christopher G. Majka / ZooKeys 2: 221-238 (2008) 222


Introduction
Th e fl at bark beetles in the superfamily Cucujoidea include the Silvanidae, Passandridae, Cucujidae, and Laemophloeidae.For many years these taxa were treated as subfamilies of the Cucujidae until they were separated by Crowson (1955).Th ey have in common their strongly dorso-ventrally fl attened form.Species in the Silvaninae, Brontini, and Laemophloeidae that occur in the wild, feed on ascomycete fungi and are found under the bark of various coniferous and deciduous trees.Species in the Telephanini are found on plants, particularly withered pendant leaves, where they probably feed primarily on fungi.Other species in genera such as Cryptolestes, Nausibius, Oryzaephilus, and Ahasverus are pests of stored grains and other dried products.Species in the Cucujidae are subcortical saproxy-MUN Memorial University of Newfoundland collection, St. John's, Newfoundland, Canada (currently on long term loan to the Canadian Forest Service, Edmonton, Alberta) NBM New Brunswick Museum, Saint John, New Brunswick, Canada NSAC Nova Scotia Agricultural College, Bible Hill, Nova Scotia, Canada NSMC Nova Scotia Museum, Halifax, Nova Scotia, Canada NSNR Nova Scotia Department of Natural Resources, Shubenacadie, Nova Scotia, Canada RWC Reginald Webster Collection, Charters Settlement, New Brunswick, Canada UMNB Université de Moncton, Moncton, New Brunswick, Canada Th e taxonomy and nomenclature follow Th omas (2002aTh omas ( , 2002bTh omas ( , 2002cTh omas ( , 2002d)).

Results
Eighteen species of fl at bark beetles are now known to occur in Atlantic Canada; 10 in New Brunswick, 17 in Nova Scotia, four on Prince Edward Island, six on insular Newfoundland, and one in Labrador (Table 1).Th e distribution of all species (native and introduced) found in the wild is shown in Figures 1 and 2. Th ese include eight species in the Silvanidae, two species in the Cucujidae, and eight species in the Laemophloeidae.No species of Passandridae have been found in the region although one, Catogenus rufus (Fabricius), does occur in neighbouring Québec.Twenty-three new provincial records are reported and nine species, Uleiota debilis (LeConte), Uleiota dubius (Fabricius), Nausibius clavicornis (Kugelann), Ahasverus advena (Waltl), Cryptolestes pusillus (Schönherr), Cryptolestes turcicus (Grouvelle), Charaphloeus convexulus (LeConte), Charaphloeus species nr.adustus, and Placonotus zimmermanni (LeConte) are newly recorded in Atlantic Canada, one of which C. sp.nr.adustus, is newly recorded in Canada.Ahasverus longulus (Blatchley) is removed from the species list of New Brunswick and Charaphloeus adustus (LeConte) is removed from the species list of Nova Scotia.One tropical Asian species, Cryptamorpha desjardinsi (Guérin-Méneville), has been intercepted in the region in imported produce, but is not established.Specifi c details follow.Uleiota debilis is newly recorded in Atlantic Canada (Fig. 1).Species of Brontini are found primarily under bark where both adults and larvae probably feed on ascomycete and other fungi (Th omas 1993(Th omas , 2002a)).In Nova Scotia recorded from white ash (Fraxinus americana L., Oleaceae), and honey locust (Gleditsia triacanthos L., Caesalpiniaceae).Uleiota dubius is newly recorded in Atlantic Canada (Fig. 1).Species of Brontini are found primarily under bark where both adults and larvae probably feed on ascomycete and other fungi (Th omas 1993(Th omas , 2002a)).Common under bark of hardwoods (Downie and Arnett 1996).In Nova Scotia recorded from maple (Acer sp., Aceraceae), and apple (Pyrus malus L., Rosaceae).Dendrophagus cygnaei is newly recorded in New Brunswick and Nova Scotia (Fig. 2).It was recorded from Newfoundland by Bousquet (1991).Species of Brontini are found primarily under bark where both adults and larvae probably feed on ascomycete and other fungi (Th omas 1993(Th omas , 2002a)).In Nova Scotia recorded from a wide variety of coniferous and deciduous forests.
In Nova Scotia Cryptamorpha desjardinsi was intercepted in bok choy, probably imported from the United States.Th ere is no evidence that the species is established.Th is species is native to tropical Asia and is now established in Florida and Alabama in the United States (Th omas 1993(Th omas , 2002a)).It is associated with plant molds and is found in sugarcane sheathes, on palmettos, on bananas, pineapples, and similar plants.Adults and larvae feed on sugarcane smut, Ustilago scitaminea Syd.(Th omas 1993).
Nausibius clavicornis is newly recorded in Atlantic Canada.Originally a Neotropical species it is now cosmopolitan.Originally subcorticolous (and also reported from old bees' nests) in the fi eld, it is now a pest of stored products, particularly raw or yellow-crystal sugar.It has also been reported from rice, dried apples, ginger, and cassia (Th omas 1993).Oryzaephilus mercator is newly recorded in Prince Edward Island.It was reported from New Brunswick, Nova Scotia, and insular Newfoundland by Bousquet (1991).Th is cosmopolitan species is one of the most common household pests in Canada.Adults and larvae feed primarily on cereal products, particularly oatmeal, bran, shelled sunfl ower seeds, rolled oats, and brown rice (Bousquet 1990).

Oryzaephilus surinamensis (Linnaeus, 1758)
NEW BRUNSWICK: Saint John Co.: Saint John, 5. IX.1902, IX.190?, W. McIntosh, (2, NBM).NEWFOUNDLAND: Ferryland (Prévost and Bain 2007) Oryzaephilus surinamensis is newly recorded in New Brunswick and Nova Scotia.Th e records from Newfoundland (Prévost and Bain 2007) are from archeological excavations of a latrine from deposits dated from approximately 1620.Th is cosmopolitan species is a serious pest of stored grain found primarily in granaries, grain elevators, and fl our mills.Adults and larvae attack both damaged grain and processed cereals (Bousquet 1990).It is also found on dried fruit, copra, nuts, and carob (Th omas 1993).Unlike O. mercator, it can survive Canadian winter conditions in unheated premises (Bousquet 1990).IX.2000, 9.IX.2000, 10.VIII.2001, 2.VI.2002, 9.VI.2002, 18.VI.2002, 22.IX.2002, coniferous  Th is introduced Palearctic species is newly recorded in Nova Scotia (Fig. 1).Bousquet (1991) reported it from New Brunswick.Species of Silvanus are found under the bark of logs and dead trees where they are at least partly fungivorous (Th omas 1993).In Nova Scotia they have most frequently been found in coniferous forests, under the bark of red spruce (Picea rubens Sarg.) and white pine (Pinus strobus L.) (Pinaceae) and on maple (Acer sp.).Ahasverus advena is newly recorded in Atlantic Canada.Th is is a cosmopolitan species that feeds on surface molds such as Penicillium glaucoma and Aspergillus sp.It has been associated with moldy copra, lima beans, pigeon peas, stored grain, fruit, nuts, corn, dried pears, cereals, on damp fl our, rice, fi gs, and apples, in coff ee beans, moldy grass, on cured ham and stored oats and decaying soybeans (Th omas 1993).

Ahasverus advena
Ahasverus longulus (Blatchley, 1910) No voucher specimens were found in any collection examined and there are no published records of the species from New Brunswick.It was included in Bousquet's (1991) checklist, but it was not recorded from there by Th omas (1993) and M. Th omas (pers.comm.) has no records of the species occurring there.Consequently this species is removed from the faunal list of New Brunswick.
Cucujus c. clavipes is newly recorded in New Brunswick.It was recorded from Nova Scotia and insular Newfoundland by Bousquet (1991) (Fig. 2).Adults and larvae are found under the bark of dead trees.Larvae are apparently predaceous (Th omas 2002c).

Pediacus fuscus Erichson, 1845
Th is Holarctic species was recorded from both New Brunswick and Labrador by Bousquet (1991) (Fig. 2).In the Old World the species is found in Estonia, Finland, Latvia, Sweden, northern Russia, and Siberia (Slipinski 2007).In North America they have been recorded from Alaska, the Northwest Territories and British Columbia east across Canada to Labrador and in the United States from Colorado, Maine, Michigan, New Hampshire, and Wisconsin (Th omas 2004).Species in the genus Pediacus are predominantly found under the bark of dead conifers (Th omas 2004).In Latvia several specimens were collected under the bark of Scotch pine (Pinus sylvestris L., Pinaceae) (Telnov et al. 2007;D. Telnov pers. comm.).Cryptolestes ferrugineus is newly recorded in Nova Scotia and Prince Edward Island.It was reported from Newfoundland by Bousquet (1991).Th is cosmopolitan species is a serious pest of stored grain in Canada where it is found mainly in granaries, grain elevators, and mills (Bousquet 1990).Cryptolestes pusillus is newly recorded in Atlantic Canada.Th is cosmopolitan species is found mainly in grain elevators and fl our mills where it feeds on damaged grain, preferably wheat (Bousquet 1990).Cryptolestes turcicus is newly recorded in Atlantic Canada.Th is cosmopolitan species is found in feed and fl our mills, grain elevators, and warehouses where it feeds on fungi growing on damaged grains (Bousquet 1990).

Laemophloeus biguttatus (Say, 1825)
Laemophloeus biguttatus is widely distributed in New Brunswick, Newfoundland, Nova Scotia, and Prince Edward Island (Bousquet 1991) (Fig. 2).Th ey are found under the bark of trees where they feed on ascomycete fungi such as Hypoxylon prob.atropunctatum (Schweinitz ex Fries) Cooke (Th omas 1993).In Nova Scotia it has been collected in coniferous and mixed forests on both red maple (Acer rubrum L., Aceraceae) and red oak (Quercus rubra L., Fagaceae).Laemophloeus fasciatus is newly recorded in Atlantic Canada (Fig. 1).It is found under bark (Th omas 1993).In Atlantic Canada it has been collected in coniferous and mixed forests and has been found on basswood (Tilia europea L., Tiliaceae).
Charaphloeus convexulus is newly recorded in Atlantic Canada (Fig. 1).Although species was originally reported from Halifax, Nova Scotia by Evans (1899), subsequent authors have overlooked this early record.Found under bark (Th omas 1993).
Placonotus zimmermanni is newly recorded in Atlantic Canada (Fig. 2).Th omas (1993) collected this species under the bark of dead hardwoods, especially oaks (Quercus spp.) on or near ascomycete fungi.In Nova Scotia it was collected on red oak (Quercus rubra).

Discussion
Of the 18 species recorded in the region, eight are adventive cosmopolitan species introduced to the region and North America.Ten are native Nearctic species, and one, Pediacus fuscus, is Holarctic.All the introduced species except for Silvanus bidentatus (a saproxylic species) are found on various stored products, whereas all the native species are saproxylic (Table 1).One tropical Asian species, Cryptamorpha desjardinsi, has been intercepted in imported produce, but is not established here.
Even with the substantial increases in the known fauna of the region (nine new species and 23 new provincial records) it is probable, given the relatively modest collecting eff ort devoted to this group of beetles in Atlantic Canada, that more species remain to be found.Six additional species have been recorded in Québec and two others in Maine (Bousquet 1991;Chandler 2001), all of which could potentially occur in Atlantic Canada.Although Ahasverus longulus has been removed from the New Brunswick faunal list, it has been recorded in Québec and should be looked for in the region.
A substantial proportion of species (44%) are introduced, similar to the 46% of non-native Bostrichiformia (Derodontidae, Dermestidae, Bostrichidae, and Anobiidae) in the Maritime Provinces (New Brunswick, Nova Scotia, and Prince Edward Island) (Majka 2007a).Th is is almost triple the proportion (15.3%) of introduced Coleoptera in the region overall (C.G.Majka, unpublished data).Seven of these eight species are synanthropic, associated with various dried, stored products.America date of detection (1620) of one, Oryzaephilus surinamensis, is from this region, from specimens excavated from a latrine in Newfoundland (Prévost and Bain 2007) (Table 2).Early dates of detection of these introduced species in Atlantic Canada (mean = 1916) are substantially later than in North America as a whole (mean = 1794), probably as a result of a lack of early collecting in this region.In contrast to many adventive terricolous beetles, a large number of which were introduced to North America in association with dry ballast imported to Atlantic Canadian ports (Lindroth 1957) Bousquet (1991), Chandler (2001), Dearborn and Donahue (1993), Downie and Arnett (1996), Sikes (2004), and the present study.the introduced fl at bark beetles are stored product pests introduced to the continent via other mechanisms.One introduced species, Silvanus bidentatus, is corticolous, has successfully colonized native habitats, and is now widely-distributed in North America.
As is typically the case with islands, the species richness of the native faunas of Prince Edward Island, Cape Breton Island, and insular Newfoundland are diminished in comparison with that of the neighbouring mainland (Table 3).Th is may represent an island-associated diminution, a paucity of collecting, an area eff ect, or a combination of these factors.Th e fauna of Cape Breton is 40% that of the combined Atlantic Canadian native fauna, that of insular Newfoundland is 30%, and that of Prince Edward Island is 10%.Majka (2007b) reported comparable numbers for 283 native saproxylic species in 18 families, subfamilies and tribes.Th e overall mean of these numbers on Cape Breton Island was 33% and on insular Newfoundland it was 28%, very similar to the proportions of fl at bark beetles.On Prince Edward Island the overall mean was 30%, substantially greater than the 10% of fl at bark beetles found on PEI.Either the fl at bark beetle fauna of Prince Edward Island is smaller than might otherwise be expected, or else collecting eff ort there has been insuffi cient to fully discern the fauna.
Although Labrador is located on the North American mainland it also has an impoverished fl at bark beetle fauna consisting solely of the Holarctic species, Pediacus fuscus.In part this refl ects the fact that substantial portions of Labrador consist of barrens, bogs, sub-arctic, low arctic, and alpine tundra that lack trees and are unsuitable for bark beetles.Furthermore the boreal forests that are found in Labrador are dominated by conifers such as black spruce (Picea mariana (Mill.)BSP) and balsam fi r (Abies balsamaea (L.) Mill, Pinaceae) with only a modest component of deciduous trees such as trembling aspen (Populus tremuloides Michx., Salicaceae) and white birch (Betula papyrifera Marshall, Betulaceae) (Anonymous 2003).Most fl at bark beetles (with the exception of P. fuscus), however, are associated largely or exclusively on hardwoods.Pediacus fuscus is the only fl at bark beetle found in the Yukon Territory, and only it and Cathartosilvanus imbellis (LeConte) have been recorded in the Northwest Territories -two other northern jurisdictions dominated by boreal coniferous forests.Majka (2007b) drew attention to the substantial number of "apparently rare" native saproxylic species found in Atlantic Canada (defi ned as those comprising ≤ 0.005% of specimens examined from the region).He drew attention to 59 such species from 14 families of beetles that represented 33% of the species in these taxa that fell into the category of "apparently rare."Amongst the fl at bark beetles, four of the 10 native species including Uleiota debilis, Uleiota dubius, Charaphloeus sp.(nr.adustus), and Placonotus zimmermanni all fall into this category, and all are associated with hardwoods.Majka (2007b) suggested that the large number of apparently rare species could be related to the long history of forest management practices.For instance, in Nova Scotia although 78% of the land base is forested, less than 1% of that land is composed of old-growth forests (Loo and Ives 2003).Short-rotation, monoculture plantation, forestry practices that have emphasized coniferous trees for fi bre production have contributed to an impoverishment of forest diversity, particularly that of long-maturing hardwood forests.It is not unreasonable to suppose that such practices have had a corresponding impact on the invertebrate faunas found in the forests of Atlantic Canada.Th e most abundant saproxylic species in the region is the introduced Silvanus bidentatus, which is principally associated with coniferous trees.Alexander (2004) draws attention to beetles in Great Britain that are associated with undisturbed forests.Six of the 180 species of beetles used to calculate the Index of Ecological Continuity (an inverse of disturbance) are fl at bark beetles including Silvanus bidentatus, Silvanus unidentatus (Olivier), Uleiota planata (Linnaeus), Pediacus depressus (Herbst), Pediacus dermestoides (Fabricius), and Notolaemus unifasciatus (Latreille) (representing three of the genera found in Atlantic Canada), an indication that some fl at-bark beetles are very susceptible to disturbance.With respect to European saproxylics, Grove (2002: 14-15) wrote that, "Many saproxylic species now survive ... only as relictual populations, 'hanging on by the tips of their tarsi' ... In the absence of positive management, the ultimate extinction of some such species (truly the 'living dead') is almost inevitable through stochastic events".Further research needs to be done in Atlantic Canada to determine the impact that forest history and current practices may have had on saproxylic species such as fl at bark beetles, and measures which might lessen or ameliorate habitat fragmentation, the disappearance of old-growth forests, and the diminution of coarse woody debris -all parameters of forests signifi cant to this functional group of beetles.
Th e earliest North

Table 1 .
Th e number of county records of Silvanidae, Cucujidae, and Laemophloeidae in Atlantic Canada , most ofNotes: NB, New Brunswick; NS, Nova Scotia; PE, Prince Edward Island; NF, insular Newfoundland; LB, Labrador.Numbers indicate the number of county records.Th ere are 15 counties in New Brunswick, 18 in Nova Scotia, and 3 on Prince Edward Island.County divisions are not employed in the province of Newfoundland and Labrador so numbers from there simply indicate the presence of species.SP, Stored Product species; SX, Saproxylic species; †, adventive Palearctic species; *, Holarctic species; §, adventive Asian species.Regional Distribution: For the purposes of this treatment, northeastern North America is taken to include of the following jurisdictions: CT, Connecticut; LB, Labrador; MA, Massachusetts; ME, Maine; NB, New Brunswick; NF, insular Newfoundland; NH, New Hampshire; NY, New York; ON, Ontario; PE, Prince Edward Island; PM, Saint-Pierre et Miquelon; QC, Québec; RI, Rhode Island; VT, Vermont.Distributional data is compiled from

Table 2 .
Earliest dates of detection of introduced Silvanidae and Laemophloeidae in Atlantic Canada NB, New Brunswick; NS, Nova Scotia; PE, Prince Edward Island, NF, insular Newfoundland; NA, North America.Boldface entries signify the earliest dates for a species in the region.