Eutarsopolipus asiaticus sp. nov. (Acari: Podapolipidae), subelytral parasite of Chlaenius costiger Chaudoir (Coleoptera: Carabidae), is described from Japan. Relationships with 18 previously described species in the myzus group of Eutarsopolipus are discussed and keys are provided to species in the myzus group. This is the first record of Eutarsopolipus in the myzus group in Japan and represents a subgroup of species in the myzus group with cheliceral stylets 90 micrometers or longer.
Mites in the family Podapolipidae (Acari: Tarsonemina) are all specialized parasites of five orders of insects: Blattodea, Heteroptera, Hymenoptera, Orthoptera and especially Coleoptera. Regenfuss (1968) placed 18 species in the genus Eutarsopolipus, all parasites of the beetle family Carabidae, in seven groups based on apomorphic and other characters. Of the 64 species of Eutarsopolipus,including the species described herein, 18 are in the myzus group.
Species in the myzus group are divided into three subgroups based on lengths of cheliceral stylets: (1) 90 micrometers or longer, (2) 45–65 and (3) less than 45. Previous studies of Eutarsopolipus species in the myzus group are: Regenfuss (1968, 1974), Husband and Swihart (1986), Husband (1998, 2000, 2001), Husband and Dastych (1999), Khaustov (2010), Husband and Husband (2012, 2013) and Hajiqanbar and Mortazavi (2012). Species in the myzus group of Eutarsopolipus with stylets 45–65 from Chlaenius praesinus Dejean in the eastern United States are being studied by R. W. Husband and D. O. Husband. Similar species from Chlaenius costiger from Japan are under study by Husband and Kurosa. The new species described herein is the first species in the myzus group parasitizing the carabid genus Chlaenius in Asia and one of the first species from the subgroup with females with stylets exceeding 90 micrometers. We also present a key to the 18 species in the myzus group.
Materials and methods
Podapolipid mites were found on ten specimens of Chlaenius costiger Chaudoir (Coleoptera: Carabidae) from Nagasaki, Shimane, Okinawa and Yamanashi Prefectures. Mites were cleared with Nesbitt's solution and mounted in Hoyer's medium.
Measurements were taken with the aid of a Zeiss compound phase contrast microscope with an ocular micrometer. Setae no longer than the diameter of setal acetabulae are listed as microsetae (m). Setae represented by acetabulae without setal remnants are listed as vestigials (v). Terminology follows Lindquist (1986). Long setae are often bent, obscured, broken or at an angle that makes measurement difficult. Setae are at least as long as indicated.
Abbreviations for institutions cited are: National Museum of Nature and Science, Tokyo, Japan (NSMT), National Museum of Natural History, Washington, D.C., U.S.A. (NMNH), Biozentrum Grindel und Zoologisches Museum, Hamburg, Germany (BGZM), University of Michigan Museum of Zoology, Ann Arbor, Michigan, U.S.A. (UMMZ), Nikita Botanical Gardens, National Scientific Center, Yalta, Ukraine (NSCY), and Department of Entomology, Tarbiat Modares University, Tehran, Iran (TMUI).
Differential diagnosis. Cheliceral stylets of adult female, male and larval female E. asiaticus longer than those of any other species in the myzus group (Table 1). Adult female with prodorsal setae v1 two times length of setae sc1 in contrast to less than two times length of setae sc1 in 16 species of Eutarsopolipus in the myzus group. Idiosomal setae c2 and h1 as well as setae d of tibiae I, II, III and tarsus III setae pl″ distinctly longer than these setae of any previously described species of Eutarsopolipus in the myzus group.
Female (Fig. 1, n=9): Gnathosoma length 65–85, width 70–83. Cheliceral stylets length 95–110, pharynx width 20–23, seta ch (dorsal gnathosomal seta) 33–42, subcapitular setae (su) 8–12, distance su-su 25.
Idiosoma. Stigmata directly anterior to setae v1, posterolateral to base of gnathosoma. Distance stigmata base-stigmata base 54–62. Idiosoma length 264–580, width 238–330 (Table 1). Prodorsal seta v1 15–20, v2 vestigial, sc1 5–8, sc2 60–97. Distance v1-v1 76–93. Plate C setae c1 5–8, c2 10–22, plate D seta d 15–20, plate EF seta e 10–15, plate H seta h1 76–93. Cupules ia and im anterior to setae d and e respectively. Distance h1-h1 25. Venter with apodemes conspicuous, coxal setae 1a 2–3, 2a 3–5 3a 10–15, seta 3b 8–12.
Legs. Setation for femur, genu, tibia, tarsus I, II, III 2-0-7-8, 0-0-4-7, 0-0-4-5, respectively. Ambulacrum I with one hooked claw, ambulacra II, III with two claws. Femur I seta l′ 12–20, tibia I seta d 60–68, solenidion ϕ 8, seta k 3, v′ 30, tarsus I solenidion ω 8, width of base of tarsus I 18. Tibia II seta d 45–47, tarsus II solenidion ω 8, pl″ 47–63. Tibia III seta d 70–72, tarsus III setae pl″ 47–63. Thornlike setae of tarsi II, III not bifid.
Male (Fig. 2, n=9): Gnathosoma length 34–41, width 40–45. Cheliceral stylets 28–32, pharynx width 8–10. Setae ch 20–25, seta su 4–5, distance su-su 15–16.
Idiosoma. Length 172–205, width 131–188 (Table 1). Prodorsal plate seta v1 11–15, v2 v, sc14–5, sc2 72–75, distance v1-v1 35–38. Plates CD, setae c1 4–5, c2 10–12, d 9–13, plate EF seta e 7–8. Aedeagus posterior, length 23–28, base width 23–27. Venter with apodemes weakly developed. Coxal setae 1a 2, 2a 2–3, 3a 6–8, 3b 7–10.
Legs. Setation for femur, genu, tibia, tarsus legs I, II, III 2-0-7-8, 0-0-4-6, 0-0-4-5, respectively. Femur I seta l′ 0–2, d m, tibia I seta d 40–48, solenidion ϕ 6–7, tarsus I solenidion ω 5–6, width of base of tarsus I 15. Tibia II seta d 23–25, tarsus II solenidion ω 6. Tibia III seta d 29–34, tarsus III seta pl″ 54–58.
Larval female (Fig. 3, n=7): Gnathosoma length 43–50, width 45–51. Cheliceral stylet length 57–64. Pharynx width 11–15, seta ch 18–25, seta su 5–6, distance su-su 17–18.
Idiosoma. Length 180–330, width 141–250 (Table 1). Prodorsal plate seta v1 8–10, seta v2 v, seta sc1 2–3, sc2 67–80, distance v1-v1 30–38. Plate C seta c1 3–5, c2 5–8, plate D seta d 4–10, plate EF seta e 6–7, plate H seta h1 90–115, h2 27–46, distance h1-h1 2–3. Venter with apodemes 1, 2 weakly developed. Coxal setae 1a 2, 2a 2–3, 3a 7–9, 3b 7–10.
Legs. Setation for femur, genu, tibia, tarsus legs I, II, III 2-0-7-8, 0-0-4-6, 0-0-4-5. Ambulacra I each with two claws (5–6), ambulacra II, III without claws. Femur I seta l′ 2–3, d m, tibia I seta d 27–32, solenidion ϕ 6–7, setae k 2, tarsus I solenidion ω 5, width of base of tarsus I 13. Tibia II seta d 12–15, tarsus II solenidion ω 6–7. Tibia III seta d 15–25, tarsus III seta pl″ 35–53.
Egg (n=10): Length 191–242, width 110–170.
Etymology. Eutarsopolipus asiaticus is derived from the Asiatic distribution of the host carabid beetle, Chlaenius costiger.
Host. All of the mites from the host specimens were found under the elytra on the metanotum, the basal portion of the metathoracic wings, and the abdominal dorsum, but rarely also on the membrane between the pro- and mesothoraces, and the basal portion of the underside of the elytra of nine specimens of Chlaenius (Haplochlaenius) costiger Chaudoir (Coleoptera: Carabidae). Beetles collected in six localities in Japan are stored in UMMZ.
Type material. Holotype, adult female (Kurosa No. 21453–5), from Chlaenius costigerChaudoir (Coleoptera: Carabidae), Sato, Mikura-jima Is., Izu Iss., Tokyo, Japan, 23 July 1975, J. Okuma leg., deposited in the National Museum of Nature and Science, Tokyo, Japan (NSMT).
Paratypes, four adult females, nine males, five larval females, eight slides with eggs, with same data as holotype; two adult females, two males, three larval females, six eggs and one vial with mites, Ôhara, Iriomote Is., Okinawa Pref., Japan, 29 April 1979, Y. Kurosa leg.; one male, one female, one larval female, one vial with mites, Mt. Yahiro-dake, Sasebo-shi, Nagasaki Pref., 1 March 1976, J. Okuma leg.; one male, two females, five larval females, one vial with mites, Mt. Yahiro-dake, Sasebo-shi, Nagasaki Pref., Japan, 24 February 1978, J. Okuma leg.; one male, one female, one vial with mites, Mt. Yahiro-dake, Sasebo-shi, Nagasaki Pref., Japan, 17 December 1981, J. Okuma, leg.; one male, one adult female, one female larva, one vial with mites, Mt. Yahiro-dake, Sasebo-shi, Nagasaki Pref., Japan, 13 February 1982, J. Okuma, leg.; two males, one female, one larval female, one vial with mites, Tomane, Oki Islands, Shimane Pref., Japan, 4 December 1972, T. Okumura leg.; one female, one larval female, Manzawa-mura, Fuji-gun, Yamanashi Pref., Japan, 12 May 1974, M. & K. Murata leg.; two males, one female, one vial with mites, Mt. Miyatsuka-yama, Toshima Is., Tokyo, Japan, 19 July 1978, J. Okuma leg.; one adult female, one male and one larval female are deposited in each of the following museums: NSMT, NMNH, BGZM, UMMZ, NSCY and TMUI.
Comparison of selected maximum measurements for species of the myzus group of the genus Eutarsopolipus: E. asiaticus (Eas), E. americanus (Eam), E. regenfussi (Er), E. tomentosi (Et), E. mirifici (Emi), E. caudatus (Eca), E. myzus (Emy), E. jacobi (Ej). All measurements are in micrometers. Although illustrated and described by Regenfuss (1968), there are no male or larval female instars of E. myzus in the Regenfuss Collection at the University of Hamburg. Male and larval female instars of E. abdominis, E. squamorum, E. thoracis and E. poecili are not described or illustrated and no specimens of these instars are in the Regenfuss Collection. Species of Eutarsopolipus in the myzus group with adult females with cheliceral stylets less than 40 micrometers are not included in this table.
Regenfuss (1968) placed five species of Eutarsopolipus in the myzus group based on two apomorphic characters: adult females with bare genua III and trochanter I of larval females with a lobe. He did not assign apomorphic or plesiomorphic status to three additional characters: adult females with femur I setae l′ long, larval females with setae h1 adjacent or nearly so and males with aedeagi as long as wide with lateral margins concave. All species, including E. asiaticus, meet criteria for males and adult females. Husband and Husband (2012) were unable to find trochanteral I lobes in North American larval Eutarsopolipus in the myzus group and we have not been able to find trochanteral I lobes in larval E. asiaticus. The significance of idiosomal lobes in adult females and possible trochanteral lobes in larval females is still under investigation.
Plesiomorphic characters found in species in the myzus group include: adult females with stigmata, ambulacra II, III with strong claws, ambulacrum I with a claw (except E. poecili Regenfuss, 1968), prodorsal setae v1, sc1 present and epimeres III well developed. Unassigned characters include adult females with femur I setae l′ setae long (except E. latus Regenfuss and E. tomentosiHusband and Dastych) and setae h1 less than 30 (except E. caudatus Regenfuss and E. asiaticusherein), male with aedeagus with lateral margins concave and larval female with plate H setae h1 adjacent or nearly so.
Key to adult females of the myzus group of Eutarsopolipus (Podapolipidae) that parasitize beetles of the genera Chlaenius, Poecilus, Scarites and Diplocheila
1. Cheliceral stylets length 90–115 2
- Cheliceral stylets shorter than 70 3
2. Setae h 1 93, setae ch 42, Nagasaki, Okinawa, Shimane, Yamanashi Prefectures and Toshima Is., Tokyo, Japan, host Chlaenius costiger E. asiaticus sp. nov. Husband and Kurosa
- Setae h 1 22–29, setae ch 30, Oceana County, Michigan, Adair and St. Louis Counties, Missouri, USA, host Chlaenius praesinus E. americanus Husband and Husband
3. Plate C or D divided 4
- Plate C or D not divided 5
4. Idiosoma elongate, slightly broader posterior to plate D, setae h 1 3–4, Michigan, USA, host Chlaenius sericeus E. davidsoni Husband
- Idiosoma pear-shaped, broader anterior to plate C, setae h 1 m, Georgia, USA, host Chlaenius aestivus E. latus Regenfuss
5. Propodosoma not covering gnathosoma, strong ambulacra I claws 6
- Propodosoma covering gnathosoma, no ambulacra I claws, Germany, host Poecilus lepidus E. poecili Regenfuss
6. Idiosoma tear-drop shaped or with wrinkled posterior lobes 7
- Idiosoma not tear-drop shaped and not with wrinkled posterior lobes 8
7. Idiosoma tear-drop shaped, posterior idiosoma smooth, Germany, host Poecilus cupreus E thoracis Regenfuss
- Idiosoma not tear-drop shaped, with posterior idiosomal lobes wrinkled, Quebec, Canada, host Poecilus lucublandus E. quebecensis Husband
8. Femur I setae l′ longer than 10 9
- Femur I setae l′ shorter than 5, Rome, Georgia, USA, host Chlaenius tomentosus E. tomentosi Husband
9. Idiosoma length two times width 10
- Idiosoma length not two times width 11
10. Plate H evident dorsally, setae 3a longer than 10, Entebbe, Uganda, host Chlaenius mirificus E. mirifici Husband
- Plate H not evident dorsally, setae 3a shorter than 5, Cheboygan Co., Michigan, USA host Chlaenius pennsylvanicus E. regenfussi Husband and Swihart
11.Idiosoma with lateral bulges 12
- Idiosoma without lateral bulges 14
12. Without posterior lobes. 13
- With posterior lobes, lateral bulges broadest at plane of plates C and D, Germany, Ukraine, host Poeciluslepidus, P. sericeus E. myzus Regenfuss
13. Lateral lobes broadest at plane of plates D and EF, Ebermannstadt, Germany, host Poecilus cupreus E. squamorum Regenfuss
- Lateral lobes broadest at plane of plate C, Ebermannstadt, Germany, host Poecilus cupreus E. abdominis Regenfuss
14. Cheliceral stylets 25–35 15
- Cheliceral stylets 45–55 16
15. Setae h 1 shorter than 5, Kerman Province, Iran, host Poecilus sp E. anichtchenkoi Hajiqanbar and Mortazavi
- Setae h 1 longer than 20, Abkhasia, Western Caucasus, host Chlaenius coeruleus E. steveni Khaustov
16. Gnathosomal setae ch 20–25 17
- Gnathosomal setae ch 10–15, Washtenaw Co., Michigan, USA, host Diplocheila impressicollis E. jacobi Husband and Husband
17. Setae h 1 56, setae 3a 12, Illmitz am Neusiedlersee, Austria, Moldavia E. caudatus Regenfuss
- Setae h 1 7, setae 3a 3–5, Jiroft City, Kerman Prov., Iran, host Scarites terricola E. terricolae Hajiqanbar and Mortazavi
With a majority of the 34,275 species of Carabidae (Lorenz, 2005) not yet examined for podapolipid mites, we anticipate additional reorganizations of groups of Podapolipidae from Carabidae as more potential host species are examined and relationships of their parasitic podapolipid mites are studied. Including E. asiaticus described herein, eight of 15 species in the myzus group and two species in the desani group have hosts in the carabid genus Chlaenius in Eurasia, North America and Africa. Most of the 864 species of Chlaenius distributed worldwide (Ball and Bousquet 2001) have not been examined for podapolipid mites in the myzus or desani groups. We anticipate many future discoveries of mites in these groups.
We are grateful to the late Mr. Takashi Okumura, Dr. Yoshiro Kurosa, Saku Medical Center, Nagano Prefecture, Japan and Jun Okuma, Sasebo-shi, Nagasaki Prefecture, Japan for material used in this work. We thank Hieronymus Dastych, Biozentrum Grindel and Zoological Museum, University of Hamburg, Hamburg, Germany for the loan of the holotype of Eutarsopolipus myzus.