Research Article |
Corresponding author: Wayne Knee ( whknee@gmail.com ) Academic editor: Farid Faraji
© 2017 Wayne Knee.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Knee W (2017) New Macrocheles species (Acari, Mesostigmata, Macrochelidae) associated with burying beetles (Silphidae, Nicrophorus) in North America. ZooKeys 721: 1-32. https://doi.org/10.3897/zookeys.721.21747
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Burying beetles (Silphidae, Nicrophorus) are hosts to a broad diversity of mites (Acari), including several species of Macrocheles Latreille, 1829 (Mesostigmata, Macrochelidae). The macrochelid fauna associated with silphids primarily in North America was surveyed; in total, 1659 macrochelids representing seven species were collected from 112 Nicrophorus beetles representing nine host species. Three new species of Macrocheles were discovered during the survey and described as Macrocheles willowae sp. n., M. pratum sp. n., and M. kaiju sp. n. The barcode region of cytochrome oxidase subunit I (COI) was amplified from the three new described species, as well as M. nataliae and M. praedafimetorum, and analysed in a small phylogeny.
Acari , carrion-feeding, COI, ecology, mite, phoresy
Carrion-feeding beetles (Silphidae) are associated with a diverse assemblage of mites, nematodes, and fungi. Nicrophorus (Silphidae) species are large-bodied beetles, that breed and feed on decaying organic matter, most often vertebrate carcasses (
The Macrochelidae (Mesostigmata) are a cosmopolitan family of predaceous mites with at least 480 described species from 20 genera, occurring in a wide variety of organic substrates where they feed on nematodes and other microinvertebrates (
Silphids were collected by various researchers across eight countries and 21 provinces or states (see acknowledgments). In Canada, most silphids were collected as bycatch from xylophagous beetle trapping by W.K. Specimens from other countries were collected primarily in pitfall traps, and others were hand-collected. Beetle specimens preserved in ethanol were shipped to Carleton University, and upon receipt specimens were placed in 95% ethanol and stored at -20°C. Using a dissecting microscope, silphids were identified to species using keys from
Genomic DNA was extracted from whole specimens for 24 hours using a DNeasy Tissue kit (Qiagen, Inc., Santa Clara, California, USA). Following extraction, mites were removed from the extraction buffer, vouchers were-slide mounted, and genomic DNA was purified following the DNeasy Tissue kit protocol. PCR amplifications were performed in a total volume of 25 µl, with 14.7 µl ddH2O, 2.5 µl 10× ExTaq buffer, 0.65 µl 25 mM MgCl2, 1.0 µl of each 10 µM primer, 2.0 µl 10 mM dNTPs, 0.15 µl ExTaq DNA polymerase, and 3 µl genomic DNA template. Primer pairs LCO1490 + HCO2198 (
Sequence chromatograms were edited and contiguous sequences were assembled using Sequencher v5.3 (Gene Codes Corp., Ann Arbor, Michigan, USA). COI sequences were aligned manually in Mesquite v3.10 (Maddison and Maddison, 2016) according to the translated amino acid sequence. COI sequences from Macrocheles subbadius (MBIOE1677-13, MBIOE1699-13) generated by the Barcode of Life Data Systems (BOLD) were included in the phylogeny. COI sequences on GenBank from two Macronyssidae (Mesostigmata) species, Ornithonyssus bacoti and O. sylviarum (FM179677, KR103486), were used as outgroup sequences. Sequences generated during this study have been submitted to GenBank (Table
Collection information, host species records and mite abundance of Macrocheles (Macro.) mites collected from Nicrophorus (Nicro.) beetles, with GenBank accession numbers for COI.
Beetle number | Beetle species | Collection location | Coordinates | Collection date | Macrocheles species | Mite abundance | GenBank number |
---|---|---|---|---|---|---|---|
N002 | Nicro. defodiens | CAN, ON, Algonquin P.P. 2 | 45.895, -78.071 | 16.vi.08 | Macro. willowae sp. n. | 1 | – |
N003 | Nicro. defodiens | CAN, ON, Algonquin P.P. 2 | 45.895, -78.071 | 16.vi.08 | Macro. willowae sp. n. | 1 | – |
N005 | Nicro. orbicollis | CAN, ON, Frontenac | 44.447, -76.577 | 17.vi.08 | Macro. willowae sp. n. | 4 | – |
N006 | Nicro. orbicollis | CAN, ON, Charleston Lake | 44.500, -76.072 | 17.vi.08 | Macro. willowae sp. n. | 4 | – |
N007 | Nicro. orbicollis | CAN, ON, Charleston Lake | 44.500, -76.072 | 17.vi.08 | Macro. willowae sp. n. | 1 | – |
N008 | Nicro. orbicollis | CAN, ON, Charleston Lake | 44.500, -76.072 | 17.vi.08 | Macro. willowae sp. n. | 1 | – |
N011 | Nicro. defodiens | CAN, ON, Algonquin P.P. 1 | 45.902, -77.605 | 16.vi.08 | Macro. willowae sp. n. | 2 | – |
N012 | Nicro. defodiens | CAN, ON, Algonquin P.P. 1 | 45.902, -77.605 | 16.vi.08 | Macro. willowae sp. n. | 2 | – |
N013 | Nicro. defodiens | CAN, ON, Algonquin P.P. 1 | 45.902, -77.605 | 16.vi.08 | Macro. willowae sp. n. | 5 | – |
N014 | Nicro. defodiens | CAN, ON, Algonquin P.P. 1 | 45.902, -77.605 | 16.vi.08 | Macro. willowae sp. n. | 7 | – |
N015 | Nicro. defodiens | CAN, ON, Algonquin P.P. 1 | 45.902, -77.605 | 16.vi.08 | Macro. willowae sp. n. | 5 | – |
N017 | Nicro. defodiens | CAN, ON, Algonquin P.P. 1 | 45.902, -77.605 | 16.vi.08 | Macro. willowae sp. n. | 1 | – |
N018 | Nicro. defodiens | CAN, ON, Algonquin P.P. 1 | 45.902, -77.605 | 16.vi.08 | Macro. willowae sp. n. | 2 | – |
N019 | Nicro. defodiens | CAN, ON, Algonquin P.P. 1 | 45.902, -77.605 | 16.vi.08 | Macro. willowae sp. n. | 2 | – |
N020 | Nicro. orbicollis | CAN, ON, Algonquin P.P. 1 | 45.902, -77.605 | 16.vi.08 | Macro. willowae sp. n. | 4 | – |
N021 | Nicro. defodiens | CAN, ON, Algonquin P.P. 1 | 45.902, -77.605 | 16.vi.08 | Macro. willowae sp. n. | 1 | – |
N022 | Nicro. defodiens | CAN, ON, Algonquin P.P. 1 | 45.902, -77.605 | 16.vi.08 | Macro. willowae sp. n. | 3 | – |
N023 | Nicro. defodiens | CAN, ON, Algonquin P.P. 1 | 45.902, -77.605 | 16.vi.08 | Macro. willowae sp. n. | 2 | – |
N024 | Nicro. defodiens | CAN, ON, Algonquin P.P. 1 | 45.902, -77.605 | 16.vi.08 | Macro. willowae sp. n. | 3 | – |
N026 | Nicro. orbicollis | CAN, ON, Charleston Lake | 44.500, -76.072 | 01.vii.08 | Macro. willowae sp. n. | 5 | – |
N028 | Nicro. defodiens | CAN, ON, Algonquin P.P. 1 | 45.902, -77.605 | 30.vi.08 | Macro. willowae sp. n. | 3 | – |
N029 | Nicro. defodiens | CAN, ON, Algonquin P.P. 1 | 45.902, -77.605 | 30.vi.08 | Macro. willowae sp. n. | 4 | – |
N031 | Nicro. defodiens | CAN, ON, Algonquin P.P. 1 | 45.902, -77.605 | 30.vi.08 | Macro. willowae sp. n. | 2 | – |
N036 | Nicro. defodiens | CAN, ON, Algonquin P.P. 1 | 45.902, -77.605 | 30.vi.08 | Macro. willowae sp. n. | 1 | – |
N037 | Nicro. defodiens | CAN, ON, Algonquin P.P. 1 | 45.902, -77.605 | 30.vi.08 | Macro. willowae sp. n. | 3 | – |
N039 | Nicro. defodiens | CAN, ON, Algonquin P.P. 1 | 45.902, -77.605 | 30.vi.08 | Macro. willowae sp. n. | 1 | – |
N040 | Nicro. defodiens | CAN, ON, Algonquin P.P. 1 | 45.902, -77.605 | 30.vi.08 | Macro. willowae sp. n. | 8 | – |
N042 | Nicro. defodiens | CAN, ON, Algonquin P.P. 1 | 45.902, -77.605 | 30.vi.08 | Macro. willowae sp. n. | 3 | – |
N043 | Nicro. defodiens | CAN, ON, Algonquin P.P. 1 | 45.902, -77.605 | 30.vi.08 | Macro. willowae sp. n. | 3 | – |
N044 | Nicro. defodiens | CAN, ON, Algonquin P.P. 1 | 45.902, -77.605 | 30.vi.08 | Macro. willowae sp. n. | 3 | – |
N046 | Nicro. defodiens | CAN, ON, Algonquin P.P. 1 | 45.902, -77.605 | 30.vi.08 | Macro. willowae sp. n. | 1 | – |
N047 | Nicro. defodiens | CAN, ON, Algonquin P.P. 1 | 45.902, -77.605 | 30.vi.08 | Macro. willowae sp. n. | 17 | – |
N048 | Nicro. orbicollis | CAN, ON, Algonquin P.P. 1 | 45.902, -77.605 | 30.vi.08 | Macro. willowae sp. n. | 5 | – |
N051 | Nicro. orbicollis | CAN, ON, Charleston Lake | 44.500, -76.072 | 15.vii.08 | Macro. willowae sp. n. | 2 | – |
N052 | Nicro. orbicollis | CAN, ON, Frontenac | 44.447, -76.577 | 30.vii.08 | Macro. willowae sp. n. | 1 | – |
N055 | Nicro. orbicollis | CAN, ON, Charleston Lake | 44.500, -76.072 | 30.vii.08 | Macro. willowae sp. n. | 3 | – |
N057 | Nicro. defodiens | CAN, ON, Algonquin P.P. 1 | 45.902, -77.605 | 29.vii.08 | Macro. willowae sp. n. | 1 | – |
N058 | Nicro. defodiens | CAN, ON, Algonquin P.P. 1 | 45.902, -77.605 | 29.vii.08 | Macro. willowae sp. n. | 2 | – |
N060 | Nicro. defodiens | CAN, ON, Algonquin P.P. 1 | 45.902, -77.605 | 29.vii.08 | Macro. willowae sp. n. | 2 | – |
N061 | Nicro. defodiens | CAN, ON, Algonquin P.P. 1 | 45.902, -77.605 | 29.vii.08 | Macro. willowae sp. n. | 5 | – |
N062 | Nicro. defodiens | CAN, ON, Algonquin P.P. 1 | 45.902, -77.605 | 29.vii.08 | Macro. willowae sp. n. | 3 | – |
N068 | Nicro. defodiens | CAN, ON, Algonquin P.P. 1 | 45.902, -77.605 | 29.vii.08 | Macro. willowae sp. n. | 9 | – |
N069 | Nicro. orbicollis | CAN, ON, Charleston Lake | 44.500, -76.072 | 12.viii.08 | Macro. willowae sp. n. | 1 | – |
N075 | Nicro. orbicollis | CAN, ON, Frontenac | 44.447, -76.577 | 26.viii.08 | Macro. willowae sp. n. | 1 | – |
N081 | Nicro. carolinus | USA, FL, Highlands Co, Lake Placid | 27.181, -81.352 | 10.iii.2009 | Macro. kaiju sp. n. | 4 | MF192750 |
N081 | Nicro. carolinus | USA, FL, Highlands Co, Lake Placid | 27.181, -81.352 | 10.iii.2009 | Macro. willowae sp. n. | 9 | MF192743 |
N086 | Nicro. orbicollis | CAN, ON, Windsor, Elgin St. | 42.261, -83.057 | 18.vi.2009 | Macro. willowae sp. n. | 1 | – |
N088 | Nicro. orbicollis | CAN, ON, Hwy 132, Dacre | 45.369, -76.988 | 25.vi.2009 | Macro. willowae sp. n. | 10 | – |
N089 | Nicro. orbicollis | CAN, ON, Carbine Rd. | 45.33, -76.371 | 25.vi.2009 | Macro. willowae sp. n. | 9 | – |
N104 | Nicro. defodiens | CAN, BC, Prince George, nr. UNBC | 53.904, -122.783 | 12.vi.2009 | Macro. willowae sp. n. | 1 | – |
N110 | Nicro. defodiens | CAN, BC, Prince George, nr. UNBC | 53.904, -122.783 | 12.vi.2009 | Macro. willowae sp. n. | 1 | – |
N113 | Nicro. defodiens | CAN, BC, Prince George, nr. UNBC | 53.904, -122.783 | 12.vi.2009 | Macro. willowae sp. n. | 4 | MF192748 |
N114 | Nicro. orbicollis | CAN, PEI, Wellington, Route 2 | 46.452, -63.949 | 06.vii.2009 | Macro. willowae sp. n. | 8 | – |
N115 | Nicro. orbicollis | CAN, PEI, Wellington, Route 2 | 46.452, -63.949 | 06.vii.2009 | Macro. willowae sp. n. | 7 | – |
N116 | Nicro. orbicollis | CAN, PEI, Wellington, Route 2 | 46.452, -63.949 | 06.vii.2009 | Macro. praedafimetorum | 1 | MF192754 |
N116 | Nicro. orbicollis | CAN, PEI, Wellington, Route 2 | 46.452, -63.949 | 06.vii.2009 | Macro. willowae sp. n. | 9 | MF192747 |
N136 | Nicro. defodiens | CAN, BC, Prince George, nr. UNBC | 53.904, -122.783 | 12.vi.2009 | Macro. willowae sp. n. | 1 | MF192749 |
N139 | Nicro. orbicollis | CAN, ON, Carbine Rd. | 45.33, -76.371 | 10.vii.2009 | Macro. willowae sp. n. | 12 | – |
N143 | Nicro. orbicollis | CAN, ON, Hamilton, Site 4-7 | 07.vii.2009 | Macro. willowae sp. n. | 100 | MF192744 | |
N145 | Nicro. orbicollis | CAN, ON, Hamilton, Site 4-7 | 07.vii.2009 | Macro. willowae sp. n. | 8 | – | |
N147 | Nicro. orbicollis | CAN, ON, Hamilton, Site 4-7 | 07.vii.2009 | Macro. willowae sp. n. | 10 | – | |
N153 | Nicro. orbicollis | CAN, NS, Dartmouth, Wright’s Cove Rd. | 44.694, -63.611 | 09.vii.2009 | Macro. willowae sp. n. | 4 | – |
N160 | Nicro. orbicollis | CAN, ON, Waterloo | 43.54, -80.211 | 07.vii.2009 | Macro. willowae sp. n. | 2 | – |
N161 | Nicro. orbicollis | CAN, ON, Waterloo | 43.54, -80.211 | 07.vii.2009 | Macro. willowae sp. n. | 8 | – |
N165 | Nicro. orbicollis | CAN, ON, Carbine Rd. | 45.33, -76.371 | 23.vii.2009 | Macro. willowae sp. n. | 17 | – |
N166 | Nicro. orbicollis | CAN, ON, Carbine Rd. | 45.33, -76.371 | 23.vii.2009 | Macro. willowae sp. n. | 8 | – |
N167 | Nicro. orbicollis | CAN, NS, Glenmont, Black Hole Rd. | 45.111, -64.296 | 17.vii.2009 | Macro. willowae sp. n. | 9 | – |
N168 | Nicro. orbicollis | CAN, NS, Cold Brook, Hwy 101 | 45.079, -64.592 | 13.vii.2009 | Macro. willowae sp. n. | 10 | MF192745 |
N169 | Nicro. orbicollis | CAN, NS, Chipman | 46.174, -65.899 | 08.vii.2009 | Macro. willowae sp. n. | 7 | – |
N174 | Nicro. orbicollis | CAN, NS, Hantsport | 45.099, -64.184 | 21.vii.2009 | Macro. willowae sp. n. | 6 | – |
N178 | Nicro. orbicollis | CAN, NS, East River off Hwy 329 | 44.583, -64.164 | 10.viii.2009 | Macro. willowae sp. n. | 4 | – |
N180 | Nicro. defodiens | CAN, NS, Debert, Industrial Park | 45.428, -63.429 | 05.viii.2009 | Macro. willowae sp. n. | 3 | – |
N181 | Nicro. orbicollis | CAN, ON, Carbine Rd. | 45.33, -76.371 | 06.viii.2009 | Macro. willowae sp. n. | 8 | MF192746 |
N185 | Nicro. vespillo | GER, Mooswald Forest, nr. Freiburg | 48.0, 7.85 | vi.2009 | Macro. nataliae | 4 | – |
N186 | Nicro. vespillo | GER, Mooswald Forest, nr. Freiburg | 48.0, 7.85 | vi.2009 | Macro. nataliae | 7 | MF192752 |
N187 | Nicro. vespillo | GER, Mooswald Forest, nr. Freiburg | 48.0, 7.85 | vi.2009 | Macro. nataliae | 1 | – |
N188 | Nicro. vespillo | GER, Mooswald Forest, nr. Freiburg | 48.0, 7.85 | vi.2009 | Macro. nataliae | 5 | MF192753 |
N191 | Nicro. orbicollis | USA, CT, Bethany | 41.462, -72.961 | 16.vii.2009 | Macro. willowae sp. n. | 1 | – |
N192 | Nicro. orbicollis | USA, CT, Bethany | 41.462, -72.961 | 14.viii.2009 | Macro. willowae sp. n. | 5 | – |
N216 | Nicro. orbicollis | USA, NH, Durham | 43.134, -70.926 | 07.vi.2009 | Macro. willowae sp. n. | 215 | – |
N218 | Nicro. orbicollis | USA, NH, Durham | 43.134, -70.926 | 07.vi.2009 | Macro. willowae sp. n. | 135 | – |
N222 | Nicro. defodiens | USA, NH, Durham | 43.134, -70.926 | 07.vi.2009 | Macro. willowae sp. n. | 30 | – |
N226 | Nicro. orbicollis | USA, NH, Durham | 43.134, -70.926 | 07.vi.2009 | Macro. willowae sp. n. | 30 | – |
N228 | Nicro. orbicollis | USA, NH, Durham | 43.134, -70.926 | 07.vi.2009 | Macro. willowae sp. n. | 97 | – |
N234 | Nicro. marginatus | CAN, AB, Onefour | 49.121, -110.47 | 17.vi.2003 | Macro. pratum sp. n. | 10 | – |
N235 | Nicro. guttula | CAN, AB, Onefour | 49.121, -110.47 | 17.vi.2003 | Macro. pratum sp. n. | 7 | – |
N235x | Nicro. marginatus | CAN, AB, Onefour | 49.121, -110.47 | 04.vii.2002 | Macro. pratum sp. n. | 3 | – |
N236 | Nicro. obscurus | CAN, AB, Onefour | 49.121, -110.47 | 04.vii.2002 | Macro. pratum sp. n. | 5 | – |
N237 | Nicro. marginatus | CAN, AB, Onefour | 49.121, -110.47 | 17.vi.2003 | Macro. pratum sp. n. | 13 | – |
N238 | Nicro. obscurus | CAN, AB, Onefour | 49.121, -110.47 | 17.vi.2003 | Macro. pratum sp. n. | 5 | – |
N239 | Nicro. obscurus | CAN, AB, Onefour | 49.121, -110.47 | 17.vi.2003 | Macro. pratum sp. n. | 11 | – |
N240 | Nicro. marginatus | CAN, AB, Onefour | 49.121, -110.47 | 17.vi.2003 | Macro. pratum sp. n. | 13 | – |
N242 | Nicro. hybridus | CAN, AB, Onefour | 49.121, -110.47 | 18.vii.2002 | Macro. pratum sp. n. | 7 | MF192751 |
N243 | Nicro. guttula | CAN, AB, Onefour | 49.121, -110.47 | 17.vi.2003 | Macro. pratum sp. n. | 7 | – |
N244 | Nicro. guttula | CAN, AB, Onefour | 49.121, -110.47 | 17.vi.2003 | Macro. pratum sp. n. | 7 | – |
N246 | Nicro. hybridus | CAN, AB, Onefour | 49.121, -110.47 | 18.vii.2002 | Macro. pratum sp. n. | 10 | – |
N274 | Nicro. marginatus | CAN, AB, Onefour | 49.121, -110.47 | 17.vi.2003 | Macro. glaber | 8 | – |
N275 | Nicro. obscurus | CAN, AB, Onefour | 49.121, -110.47 | 17.vi.2003 | Macro. glaber | 1 | – |
N295 | Nicro. carolinus | USA, NE, Kearney Co. | 05.vi.2009 | Macro. kaiju sp. n. | 1 | – | |
N295 | Nicro. carolinus | USA, NE, Kearney Co. | 05.vi.2009 | Macro. sp. | 4 | – | |
N298 | Nicro. carolinus | USA, NE, Kearney Co. | 05.vi.2009 | Macro. kaiju sp. n. | 2 | – | |
N298 | Nicro. carolinus | USA, NE, Kearney Co. | 05.vi.2009 | Macro. sp. | 3 | – | |
N303 | Nicro. pustulatus | USA, NE, Kearney Co. | 13.vii.2009 | Macro. pratum sp. n. | 3 | – | |
N308 | Nicro. marginatus | CAN, AB, Onefour | 49.121, -110.47 | 17.vi.2003 | Macro. pratum sp. n. | 86 | – |
N329 | Nicro. orbicollis | USA, NH | 2009 | Macro. willowae sp. n. | 41 | – | |
N330 | Nicro. orbicollis | USA, NH | 2009 | Macro. willowae sp. n. | 91 | – | |
N331 | Nicro. orbicollis | USA, CT, Bethany | 41.462, -72.961 | 2009 | Macro. willowae sp. n. | 13 | – |
N332 | Nicro. carolinus | USA, FL, Highlands Co, Lake Placid | 27.181, -81.352 | 10.iii.2009 | Macro. kaiju sp. n. | 11 | – |
N333 | Nicro. carolinus | USA, FL, Highlands Co, Lake Placid | 27.181, -81.352 | 10.iii.2009 | Macro. kaiju sp. n. | 74 | – |
N334 | Nicro. carolinus | USA, FL, Highlands Co, Lake Placid | 27.181, -81.352 | 10.iii.2009 | Macro. willowae sp. n. | 1 | – |
N334 | Nicro. carolinus | USA, FL, Highlands Co, Lake Placid | 27.181, -81.352 | 10.iii.2009 | Macro. kaiju sp. n. | 26 | – |
N334 | Nicro. carolinus | USA, FL, Highlands Co, Lake Placid | 27.181, -81.352 | 10.iii.2009 | Macro. sp. | 1 | – |
N335 | Nicro. carolinus | USA, FL, Highlands Co, Lake Placid | 27.181, -81.352 | 10.iii.2009 | Macro. kaiju sp. n. | 45 | – |
N336 | Nicro. marginatus | USA, NE, Kearney Co. | vi.2009 | Macro. pratum sp. n. | 9 | – | |
N338 | Nicro. defodiens | USA, NH, Durham | 43.134, -70.926 | 07.vi.2009 | Macro. willowae sp. n. | 8 | – |
N339 | Nicro. defodiens | USA, NH, Durham | 43.134, -70.926 | 07.vi.2009 | Macro. willowae sp. n. | 163 | – |
N346 | Nicro. orbicollis | CAN, ON, Hwy 132, Dacre | 45.369, -76.988 | 06.viii.2009 | Macro. willowae sp. n. | 6 | – |
N347 | Nicro. orbicollis | CAN, ON, Carbine Rd. | 45.33, -76.371 | 06.viii.2009 | Macro. willowae sp. n. | 16 | – |
Pairwise distances were calculated using neighbour-joining (NJ) analyses with the Kimura-2-parameter (K2P) model in PAUP* v4.0b10 (
MrModeltest v2.3 (
Acarus marginatus Hermann, 1804 (= Acarus muscae domesticae Scopoli, 1772), by original designation.
Type material. Holotype: female (CNC829414) on Nicrophorus orbicollis (N088, female) collected near Dacre, Ontario, Canada (45.369, -76.988), 25.vi.2009, coll: W. Knee.
Paratypes (26): Nine females (CNC829415–829423) with the same collection information as the holotype; 15 females (CNC829424–829438) on N. defodiens (N222, female), Durham, New Hampshire, USA (43.134, -70.926), 07.vi.2009, coll: W. Knee & M. Scott; female (CNC829439) on N. defodiens (N136, female), Prince George, near University of Northern British Columbia campus, British Columbia, Canada (53.904, -122.783), 12.vi.2009, coll: W. Knee & R. Dawson; female (CNC829440) on N. orbicollis (N143, male), Hamilton, Ontario, Canada, 7.vii.2009, coll: W. Knee.
Other material. 1241 mites examined from British Columbia, Nova Scotia, Ontario, Prince Edward Island, Connecticut, Florida, and New Hampshire on N. carolinus, N. defodiens, and N. orbicollis (Table
As for Macrocheles (see
Dorsal idiosoma (Fig.
Ventral idiosoma (Figs
Gnathosoma (Fig.
Legs (Fig.
Unknown.
This species is named after my daughter Willow Knee. May it inspire her to notice the little creatures as well as the big.
Macrocheles willowae sp. n. is most similar to M. merdarius (Berlese), M. nemerdarius Krantz and Whitaker, and M. pratum sp. n. Macrocheles merdarius is frequently found in litter, manure and compost worldwide, feeding on nematodes and eggs of insects (
Macrocheles nemerdarius was described from the nest of a mouse, Peromyscus in Maryland and the nest of the eastern woodrat Neotoma floridana in Florida, USA, and this species is also phoretic on coprophilous beetles (
Female M. willowae sp. n. differs from that of M. pratum sp. n. in having marginal and submarginal setae slightly longer than dorsal hexagonal setae. Genu and tibia IV with slight ridge on anterolateral and posterolateral surfaces in M. willowae sp. n., while M. pratum sp. n. only has a ridge on the posterolateral surface. Seta J5 is slightly shorter than Z5 and more spinose in M. willowae sp. n., J5 is less than half as long as Z5 in M. pratum sp. n. Punctures on the sternal shield are smaller and less prominent in M. willowae sp. n. than in M. pratum sp. n. The ventrianal shield is longer than wide for both species, but the shield is slightly narrower in M. pratum sp. n., ratio of 1.4 compared to 1.3 for M. willowae sp. n.
In
Type material. Holotype: female (CNC829441) on Nicrophorus marginatus (N336, female) collected in Kearney Co., Nebraska, USA, vi.2009, coll: W. Knee & W. Hoback.
Paratypes (11): eight females (CNC829442–829449) with the same collection information as the holotype; two females (CNC829450, 829451) on N. hybridus (N242, female), Onefour, Alberta, Canada, 18.vii.2002, coll: W. Knee & D. Johnson; female (CNC829452) on N. guttula (N235, female), Onefour, Alberta, 17.vi.2003, coll: W. Knee & D. Johnson.
Other material. 184 mites examined from Alberta and Nebraska on Nicrophorus guttula, N. hybridus, N. marginatus, N. obscurus, and N. pustulatus (Table
All dorsal and ventral setae smooth and spinose, except J5 barbed and much shorter than Z5. Seta j1 simple with rounded tip, j1 slightly longer than z1. Dorsal hexagonal setae slightly longer than marginal and submarginal setae. Dorsal shield with moderate reticulations throughout, except smooth in dorsal hexagonal area and between j4 setae, without well-defined procurved line, sigillary rami absent. Sternal shield more than twice as wide as long, punctures moderate size, posterior margin concave. Well defined l.m.t. and l.o.a.; l.o.a. contacts l.m.t. Well defined l.arc. contacts l.o.a., l.ang. and l.o.p. well defined laterally but faint medially. Well defined a.p.l., but a.p.p. not well defined. Ventrianal shield longer than wide (ratio 1.4). Arthrodial brush as long as movable digit. Genu IV with six setae. Femur IV setae ad2, pd1 prominent spikes with flattened forked tip.
Dorsal idiosoma (Fig.
Ventral idiosoma (Figs
Gnathosoma (Fig.
Legs (Fig.
Unknown.
Pratum (Latin neuter noun) means “meadow”. This species was only collected in Kearney County, Nebraska and Onefour, Alberta, which are in the prairies.
The female of Macrocheles pratum sp. n. is most similar to those of M. willowae sp. n., M. nemerdarius, M. spinipes Berlese, and M. grossipes Berlese. Macrocheles pratum sp. n. differs from M. willowae sp. n. as outlined in the M. willowae sp. n. description.
Female M. pratum sp. n. differs from that of M. nemerdarius in having larger more prominent punctures on the sternal shield, the posterior margin of the sternal shield is more concave, pon seta is smooth not weakly pilose, j1 is only slightly longer than z1 not 1.5 times as long, J5 is shorter and broader for M. pratum sp. n. (9) than for M. nemerdarius (13), and the ventrianal shield is narrower, length to width ratio of 1.4 for M. pratum sp. n. and 1.2 for M. nemerdarius. Measurements were made examining M. nemerdarius holotype specimen loaned from the National Museum of Natural History, Smithsonian Institution.
Macrocheles spinipes and M. grossipes are associated with coprophilous beetles (
Type material. Holotype: female (CNC829453) on Nicrophorus carolinus (N333, male) collected Highlands Co. Lake Placid, Florida, USA (27.181, -81.352), 10.iii.2009, coll: W. Knee & S. Peck.
Paratypes (28): 14 females (
Other material. 134 mites examined from Florida and Nebraska on N. carolinus (Table
Dorsal setae smooth and spinose, except r3, r4, s6, z6, S1–S5, Z1–Z5, J2 barbed distally, J5 barbed, marginal and submarginal setae barbed distally. Seta j1 smooth, spike, tapered distally with rounded tip, slightly longer than z1. Seta J5 much shorter than Z5. Dorsal hexagonal setae as long as marginal and submarginal setae. Dorsal shield smooth medially with faint reticulations near shield margins, shield tapers from humeral region to posterior margin. Dorsal shield without well-defined procurved line, sigillary rami absent. Setae on sternal, genital and ventrianal shields, and ZV1 smooth and spinose, other ventral setae in soft integument barbed distally. Sternal shield wider than long, punctures small, posterior margin slightly concave. Well defined l.m.t. and l.o.a.; l.o.a. contacts l.m.t. Well defined l.arc. contacts l.o.a., l.ang. and l.o.p. well defined laterally but faint medially. Well defined a.p.l., but a.p.p. not well defined. Ventrianal shield longer than wide (ratio 1.5), pon longer than pan, pon slightly spatulate. Arthrodial brush nearly as long as movable digit. Genu IV with six setae.
Dorsal idiosoma (Fig.
Ventral idiosoma (Figs
Gnathosoma (Fig.
Legs (Fig.
. Unknown.
Kaiju, 怪獣, from Japanese means strange beast, and refers to giant monsters such as Godzilla or Mothra. Female M. kaiju sp. n. is relatively unique morphologically when compared to other Macrocheles species associated with beetles, it is relatively large, has a unique dorsal shield shape, and bears numerous setae with distinct forms.
Female M. kaiju sp. n. is different from that of any other described Macrocheles species; however, it does fit the Macrocheles generic description (see Hyatt and Emberson 1988). Female M. kaiju sp. n. has two character states that are irregular for Macrocheles but somewhat similar to Holostaspella (Macrochelidae) species: the anterior margin of the dorsal shield wraps around onto the ventral surface such that j1 is on a slight projection on the venter; and a slight ridge is present on femur II. Holostaspella species are characterised in part by females having a spur on femur II, and j1 being on a tuberculate anterior extension of the dorsal shield but not wrapped around onto the venter. Macrocheles kaiju sp. n. differs from that of Holostaspella species in having weak ornamentation on the dorsal shield, its lateral regions without a series of depressions; j1 is smooth and not pectinate, j1 is on a slight projection and not a prominent tuberculate extension; sternal shield weakly ornamented and without strong median ridge; and metasternal shields small and always free of endopodal shields.
COI was amplified from 14 Macrocheles specimens representing six species, with 689 characters in total, 430 constant, 39 parsimony-uninformative, 220 parsimony-informative. NJ analysis (K2P) was performed on 14 ingroup Macrocheles specimens. Average intraspecific pairwise distance was low (1.2% ±1.4), and the maximum intraspecific divergence observed was for M. willowae sp. n. (2.8%). The higher than average intraspecific divergence for M. willowae sp. n. was due to the divergence between mites from different host species. Pairwise distance between M. willowae sp. n. mites from N. defodiens and those from N. orbicollis and N. carolinus was higher than average (5.2% ±0.1), while divergence among mites from N. defodiens and mites from N. orbicollis and N. carolinus was low, 0.1 and 0.6% respectively. Mean interspecific divergence was high (20% ±2.8), and the maximum divergence observed was between M. nataliae and M. subbadius (25%). The range of intra- (0.3–2.8%) and interspecific (15–25%) pairwise divergence did not overlap.
The majority rule consensus tree from the BI analysis of COI was well supported, with all nodes having high posterior probabilities, and eight nodes with 100% support (Fig.
Majority rule consensus tree of 19502 trees generated by Bayesian MCMC analysis (10 million generations) of 689bp fragment of COI from 14 ingroup specimens representing six Macrocheles species, and two outgroup specimens representing two species, posterior probabilities >50% shown above branches.
Seven species of macrochelids were collected from 112 Nicrophorus beetles representing nine species from three countries (Canada, USA, Germany) and 10 provinces or states (Table
A total of 1659 Macrocheles mites were collected from 112 beetles, M. willowae sp. n. (1268 mites on 86 beetles) was the most abundant, second most abundant was M. pratum sp. n. (196 mites on 15 beetles), M. kaiju sp. n. (163 mites on 7 beetles) was the third most abundant, and the four other species of Macrocheles collected were at low abundances (32 mites total on 10 beetles) (Table
The species with the greatest geographic range was M. willowae sp. n., collected from 22 sites, across seven provinces/states in Canada and USA. Macrocheles pratum sp. n. was collected from a single site in Alberta (Canada) and from another site in Nebraska (USA). Macrocheles kaiju sp. n. was collected from one site in Florida and another site in Nebraska, USA. The four other macrochelid species collected were each found in a single locale (Table
COI sequences generated in this study were compared against those on GenBank and BOLD, and M. willowae sp. n. was the only species to have high level (100%) matches on BOLD. These matching sequences belonged to generic level identified specimens from Alberta, Ontario, Saskatchewan, Nova Scotia, and Florida. The species briefly diagnosed by Dr. W. Yoder was collected from three species of rodents in Maryland, Michigan and Prince Edward Island. Combined together, results from this study, BOLD and Dr. W. Yoder’s findings, the geographic distribution of M. willowae sp. n. may cover 11 provinces or states in Canada and USA.
I am grateful to D. Johnson, D. Sikes, J. Müller, J. Sweeney, M. Nishikawa, M. Schilthuizen, M. Scott, P. Smiseth, R. Dawson, S. Peck, S. Suzuki, S. Trumbo, M. Locke, W. Hoback, and W. Hunting for providing numerous beetle specimens from around the world. I also thank T. Hartzenberg for her assistance in the field and the lab, as well as the private land owners who permitted sampling on their property. I thank G.W. Krantz and E.E. Lindquist for their comments on an earlier draft of this manuscript, and F. Beaulieu for his input on the figures, and pores and poroids. I also thank the National Museum of Natural History, Smithsonian Institution, and Oregon State University Arthropod Collection for lending type material and vouchers for examination. I thank the Bavarian State Collection of Zoology (Staatliche Naturwissenschaftliche Sammlungen Bayerns – SNSB), Barcoding Fauna Bavarica (BFB) and the German Barcode of Life (GBOL) for sharing Holostaspella subornata sequence data. This research was conducted with a permit to collect in Provincial Parks issued by Ontario Parks and coordinated by B. Steinberg. This study was funded in part by an NSERC Discovery Grant to M.R. Forbes.