Quedius molochinoides, Smetana, 1965

Hansen, Aslak Kappel, Brunke, Adam, Simonsen, Thomas & Solodovnikov, Alexey, 2022, Revision of Quedius sensu stricto (Coleoptera: Staphylinidae), Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 62 (1), pp. 225-299 : 271

Quedius molochinoides -group

Diagnosis. Species of medium to large size with two interocular punctures between anterior frontal punctures ( Fig. 6G ). Body dark, elytra and appendages variable in coloration, from completely dark to reddish-brown or light brown. Eyes medium sized, temples relatively large, with temporal puncture separated from posterior margin of eye by distance equivalent to diameter of this puncture. Scutellum punctate and pubescent. Restricted to the Nearctic Region.

Comments. The Nearctic Q. molochinoides -group currently includes five species of which four ( Q. molochinoides , Q. horni and Q. lanei , now also Q. altanai ) are impossible to separate morphologically from each other without dissection of male genitalia. Only the northern Q. labradorensis can be confidently delimited within the group based on its larger size and pale basal three antennomeres. Our thorough examination of the entire group showed that Q. horni is most easily recognized based on the aedeagus. This species is now known from the Pacific Northwest, from Oregon to southern Alaska, including Vancouver Island and Haida Gwaii (most of ecoregion 7.1). Most specimens of this species were taken on coastal sites or inland near rivers and creeks to mid elevaton in the Cascades and Mount Olympia, suggesting its close association with wet habitats. Presumably this species is somewhat halotolerant. When specimens of what was known as Q. lanei , were closely examined morphologically, we found two distinct morphotypes distinguished by differences in male genitalia. Species from the eastern foothills of the Cascades, the Sierra Nevada and the Blue Mountains (ecoregions 6.2.8, 6.2.9, 6.2.12) represent a morphotype with a broader paramere and median lobe, the latter being acuminate near apex ( Figs 16D , 17 ). This includes specimens from the Sierra Nevada (Nevada and California), which were earlier assigned to Q. molochinoides (e.g., Sආൾඍൺඇൺ 1971a). Specimens from the central and southern Rockies as well as western Sierra Madre (ecoregions 6.2.10, 6.2.13, 6.2.14, 6.2.15, 13.1.1) represent a different morphotype with a more slender paramere and median lobe, the latter being non-acuminate ( Figs 16C , 17 ). COI sequences of both morphotypes showed that four specimens corresponding to the first morphotype from Lake Tahoe in Nevada, Lassen National Forest in California, Gearhart Mountains in Oregon, and Strawberry Range in Oregon, formed a group, separate from the fifth specimen corresponding to the second morphotype ( Fig. 4 ). The central-southern Rockies morphotype was only represented by a single incomplete sequence (407 bp) from Red Mountain Pass in Colorado. This sequence was over 6% divergent from all Q. lanei sequences, but only 1.2% from Q. molochinoides -group 3 (see below), from which it is morphologically distinct ( Table 2 ). Based on the discovered congruence between the morphological and molecular groups, as well their obvious allopatry ( Fig. 21 ), we suggest that Q. lanei is a species restricted to the eastern foothills of the Cascades, Sierra Nevada and Blue Mountains, whereas a new species, Q. altanai sp. nov., is described for specimens from the central and southern Rockies, as well as western Sierra Madre (teal in Fig. 21 ). Quedius molochinoides showed genetic subclustering of COI barcodes into three distinct BINs ( Table 2 ). One BIN ( Q. molochionide s-group 1) was restricted to the Canadian national parks of Banff and Waterton (ecoregion 6.2.4), an area delimited by the Rocky Mountains Trench to the West, where it is replaced by another BIN ( Q. molochinoides -group 2), and the Canadian Plains to the east, which lack Q. molochinoides . In the north, this group is replaced by Q. molochinoides -group 3 from Jasper National Park, indicating a divide between groups 1 and 3 around Snow Dome peak and the Arctic Divide. One potential split is the Athabasca River Valley, that may have acted as a post-glacial distribution barrier combined with latitudinal climatic gradients. The extent of the distribution of group 1 southwards is still unknown, but it may very well extend into northern-central Montana and Idaho ( Figs 4 , 22 ). The Q. molochionides -group 2 is confined to the Canadian Rockies west of the Rocky Mountains Trench (ecoregion 6.2.3) and towards the North continuing to the Pacific Coast in Alaska, to the Kenai Peninsula northwards (ecoregion 6.1 and northern part of 7.1). The Q. molochinoides -group 3 is present from Becharof Peninsula in the west across the North American Taiga to glacial refugia of New England, Quebec and Newfoundland in the East (ecoregions 4, 5, and partly 6.1 and 7.1). Our results show that apparently these three molecular BINs within Q. molochinoides have distinctly allopatric distributions and thus potentially have limited gene flow among each other. However, since we have been unable to find morphological characters clearly separating them, for now we refrain from describing them as species. If future work shows that these are in fact distinct, then they may be described as separate species. Our results add further information to the complex diversification patters found in the Canadian Rocky Mountains as illuminated through a series of studies on the Spruce Budworm complex ( Lepidoptera : Tortricidae : Choristoneura ) (Lඎආඅൾඒ & SඉൾඋඅංඇG 2010, 2011; Bඋඎඇൾඍ et al. 2017, Dඎඉඎංඌ et al. 2017). Similar to these studies, genome-wide sequencing may be needed to confidently resolve the population/species boundaries and distribution patterns in the Q. molochinoides group.

Figures

Fig.6. Head and pronotal chaetotaxy of Quedius s. str.A – general scheme; B – Q. curtipennis Bernhauer, 1908, C – Q. fuliginosus (Gravenhorst, 1802); D – Q. levicollis Brullé, 1832; E – Q. afrofuliginosus Gusarov, 1991; F – Q. molochinus- and Q. laticollis-groups; G – Q. molochinoides-group. Abbreviations as follows: anterior frontal puncture (AFP); basal punctures (BP); interocular punctures (IOP); lateral puncture (LP); lateral row (LR); posterior frontal puncture (PFP); parocular punctures (POP); sublateral row (SLR).

Fig. 16. Aedeagus of Quedius s. str. A – Q. labradorensis Smetana, 1965; B – Q. horni Hatch, 1957; C – Q. altanai Hansen & Brunke, sp. nov.; D – Q. lanei Hatch, 1957; E – Q. molochinoides Smetana, 1965. I – parameral view of whole aedeagus, II – apices of paramere in antiparameral view with peg setae, III – lateral view of whole aedeagus, IV – apices of median lobe at an angle between parameral and lateral view.

Fig. 17. Variation in genitalic morphology of species from Quedius molochinoides-group.From left to right for each specimen, first paramere then median lobe (parameral view) and lastly median lobe (lateral view) are given. For each specimen locality is noted underneath.

Fig. 4. Phylogeny of Quedius s. str. species based on Bayesian Inference (BI) and Maximum Likelihood (ML) COI barcodes (part 2). BI posterior probabilities (PP), ML ultrafast bootstrap support (UFB) and ML SH-aLRT test are shown. Nodes coloured as: green, PP ≥ 0.90, and either UFB ≥ 95 or SH-aLRT ≥ 80; yellow, one of PP ≥ 0.90, UFB ≥ 95 or SH-aLRT ≥ 80; red, PP <0.90, UFB <95 and SH-aLRT <80.

Fig. 21. Distribution of Quedius unicolor Kiesenwetter, 1847 (top),.Q. labradorensis Smetana, 1965 (middle), Quedius molochinoides-group (bottom). Barcoded specimens are denoted with +.

Fig. 22. Distribution of Quedius molochinoides Smetana, 1965 (top), and Q. laticollis (Gravenhorst, 1802) and Q. strenuus Casey, 1915 (bottom).