Taxonomic revision of the family Eosentomidae (Hexapoda: Protura) from Japan 2701
Author
Nakamura, Osami
text
Zootaxa
2010
2010-12-03
2701
1
109
journal article
11755334
Eosentomon hiroshianum
Nakamura
sp. nov.
Figs. 23–24
;
Table 9
Type specimens.
Holotype
female (
NSMT
–Ap 473), Mt. Komaga–take, Kanegasaki–machi,
Iwate Prefecture
,
39º11'21"N
,
140º55'41"E
,
920 m
elevation, litter of a forest dominated by
F. crenata
and
Q. crispula
,
18-VIII-2001
, H. Tamura
et al.
leg.
Paratypes
:
four females
(
NSMT
–Ap 474–477), same data as for the
holotype
;
two females
(
NSMT
–Ap 478–479), Mt. Komaga–take, Kanegasaki–machi,
Iwate Prefecture
,
820 m
elevation, litter of a forest dominated by
F. crenata
,
18-VIII-2001
, H. Tamura
et al.
leg.
Other specimens examined
.
Nine males,
7 females
, 11 maturi juniores,
11 larvae
I, same data as for the holotype;
3 males
,
2 females
, 2 maturi juniores,
2 larvae
I,
820 m
elevation,
2 females
, two maturi juniores,
1020 m
elevation, litter of a forest dominated by
F. crenata
and
Q. crispula
,
3 males
,
6 females
,
1130 m
elevation, litter of a forest dominated by
F. crenata
, Mt. Komaga
–take,
Kanegasaki
–machi,
Iwate Prefecture
,
18-VIII-2001
,
H. Tamura
et al.
leg.;
2 males
,
1 female
,
39º50'38"N
,
141º00'53"E
,
1500 m
elevation, litter of a forest dominated by
Betula ermanii
,
6 males
,
3 females
, 1 maturus junior,
39º50'35"N
,
141º01'08"E
,
1280 m
elevation, litter of a forest dominated by
B. ermanii
,
3 males
,
1 female
, 2 maturi juniores,
39º50'29"N
,
141º01'22"E
,
1080 m
elevation, litter of a forest dominated by
F. crenata
and
Q. crispula
,
2 males
,
1 female
, 1 maturus junior,
2 larvae
II,
39º50'22"N
,
141º01'22"E
,
820 m
elevation, litter of a forest dominated by
Q. crispula
and
F. crenata
, Mt.
Iwate
–san,
Takizawa
– mura,
Iwate Prefecture
,
28-VI-1985
,
O. Nakamura
leg.
Description.
Body length 1164 (870–1400) µm. Head 130 (128 –147) µm long, 105 (106–114) µm wide. Setae
aa
,
pa
and
m4
present, sensilla
as
and
ps
present (
Fig. 23A
); seta
sp
1.9 (1.7–2.0) times longer than
p
; sensilla
pp
distinct (
Fig. 23B
), (2–3 µm long). Labral setae present (
Figs. 23C, D
). Seta
rs
inflated, shorter than
sr
(
Figs. 23C, D
). On maxillary palpus (
Fig. 23E
) sensillum
md
, 9 (8–10) µm, longer than
ml
, 7 (7–8) µm. Digits on galea developed and similar to each other (
Fig. 23F
). Mandible with three teeth (
Fig. 23G
). Clypeal apodemes distinct (
Fig. 23A, C
). Pseudoculus almost circular, 12 (10–13) µm long, (10–12 µm wide), without inner structure, but one central spot rarely observed (
Fig. 23H
),
PR
= 11 (10–14).
Foretarsus length (
Figs. 23I, J
) 105 (98–112) µm; claw 22 (20–24) µm, TR = 4.9 (4.4–5.4); empodium 21 (20– 22) µm, EU = 0.9 (0.8–1.0); sensillum
s
as long as or slightly longer than claw, 22 (22–26) µm. Sensillum
t1
nearer to α
3'
than to α
3
, BS = 1.1 (1.1–1.2);
t2
thin;
t3
thin, not reaching tarsus;
a
thin, not reaching base of γ
2
;
b
reaching base of
e
;
c
not surpassing base of γ
3
;
d
long, surpassing base of α
5
;
e
and
g
long and spatulate;
f1
thin, surpassing tarsus;
f2
short;
a'
surpassing base of
t1
;
b'1
absent;
b'2
reaching base of α
5
;
c'
anterior to base of α
6
, on the line between α
6
and δ
5
, not surpassing tarsus. Length of middle tarsus 53 (51–58) µm, length of claw 16 (13–17) µm; hind tarsus 70 (67–75) µm, claw 18 (17–19) µm; empodia on both tarsi shorter than 1/5 of claw length (
Fig. 23K
), 2 (1–3) µm long; on hind tarsus (
Fig. 23K
)
D2
and
D4
thin spine-like,
D4
longer and more slender in distal part than
D2
.
Tracheal camerae long, distally contracted (
Fig. 23L
). Central lobe incised (
Fig. 23M
). Laterostigmata II–IV large, with no inner structure; those on V–VII small. On female squama genitalis (
Fig. 24A
) caput processus swan's head-like, filum processus long, median sclerotization present. Male genitalis with long basiperiphallar setae (
Fig. 24B
).
Chaetotaxy as in
Table 9
. On thoracic tergites II–III,
P1a
seta-like, slightly longer than
P1
, posterior to
P1–P2
, slightly nearer to
P1
than to
P2
;
P2a
seta-like, shorter than
P1
, at same level with
P2–P3
. On abdominal tergites I– VII,
P1a
sensillum-like and shorter than about one-third length of
P1
, at hind margin (
Figs. 24C–F
);
P2a
on II–IV filiform and longer than
P1
(
Fig. 24D
), those on V filiform and as long as
P1
, those on VI–VII filiform, shorter than
P1
, but two times longer than
P1a
(
Figs. 24E, F
); on tergite VIII (
Fig. 24G
)
P1a'
without basal dilatation and slightly anterior to
P2
;
P2a
linear.
FIGURE 23.
Eosentomon hiroshianum
sp. nov.
A, dorsal view of head, left side; B, sensilla posterior to pseudoculus; C, labrum and rostral region; D, labral and rostral setae, lateral view; E, maxillary palpus; F, galea; G, mandible; H, pseudoculus; I, interior view of foretarsus; J, exterior view of foretarsus; K, dorsal view of hind tarsus; L, tracheal camerae on thoracic tergite II; M, central lobe on abdominal tergite VI. C, E–G, I–M, holotype, female. A, B, D, H, paratype, female. Scales: 20 µm.
Maturus junior.
Body length 904–1034 µm. Head 128–139 µm long, 91–105 µm wide; pseudoculus 10–11 µm long,
PR
= 13–14. Foretarsus length 90–95 µm, claw 19–20 µm, TR = 4.8–5.0; empodium 18–20 µm, EU = 0.9– 1.0; sensillum
s
slightly longer than claw, 20–22 µm. Length of middle tarsus 49–51 µm, length of claw 15 µm, empodium 2 µm long; hind tarsus 61–64 µm, claw 16 µm, empodium 2–3 µm. Shape and position of foretarsal sensilla same as those of imago; BS = 1.1.
FIGURE 24.
Eosentomon hiroshianum
sp. nov.
A, female squama genitalis; B, male squama genitalis; C, posterior setae on abdominal tergites I; D, posterior setae on abdominal tergites III; E, posterior setae on abdominal tergites VI; F, posterior setae on abdominal tergites VII; G, posterior margin of abdominal tergite VIII; H, abdominal tergites II-IV of larva II. C–G, holotype, female; A, paratype, female; B, paratype, male; H, larva II from Mt. Iwate-san, Iwate Prefecture. Scales: 20 µm.
TABLE 9.
Chaetotaxy of
Eosentomon hiroshianum
sp. nov.
Larva I |
Larva II |
Maturus junior |
Imago |

Formula |
Primary setae |
Formula |
Secondary setae |
Formula |
Tertiary setae |
Formula |
Complementary setae |

(Dorsal) |

Thorax |
I |
2 |
1 |
4 |
2 |
4 |
4 |

II |
4 |
A2, M |
6 |
A4 |
6 |
6 |

12 |
P1, 1a, 2, 3, 4, 5 |
14 |
P2a |
16 |
P3a |
16 |

III |
4 |
A2, M |
6 |
A4 |
6 |
6 |

14 |
P1, 1a, 2, 3, 4, 5, 6 |
18 |
P2a, 4a |
20 |
P3a |
20 |

Abdomen |
I |
0 |
0 |
4 |
A1, 2 |
4 |

10 |
P1, 1a, 2, 3, 4 |
12 |
P2a |
12 |
12 |

II |
0 |
0 |
10 |
A1, 2, 3, 4, 5 |
10 |

12 |
P1, 1a, 2, 3, 4, 5 |
16 |
P2a, 4a |
16 |
16 |

III |
0 |
2 |
A4 |
10 |
A1, 2, 3, 5 |
10 |

12 |
P1, 1a, 2, 3, 4, 5 |
16 |
P2a, 4a |
16 |
16 |

IV |
0 |
4 |
A4, 5 |
10 |
A1, 2, 3 |
10 |

12 |
P1, 1a, 2, 3, 4, 5 |
16 |
P2a, 4a |
16 |
16 |

V-VI |
0 |
4 |
A4, 5 |
8 |
A1, 2 |
8 |

12 |
P1, 1a, 2, 3, 4, 5 |
16 |
P2a, 4a |
16 |
16 |

VII |
0 |
4 |
A4, 5 |
4 |
4 |

12 |
P1, 1a, 2, 3, 4, 5 |
16 |
P2a, 4a |
16 |
16 |

VIII |
6 |
M2, 4, 5 |
6 |
6 |
6 |

7 |
Pc, 1a, 2, 2a |
9 |
P1a’ |
9 |
9 |

IX |
8 |
1, 2, 3, 4 |
8 |
8 |

X-XI |
8 |
1, 2, 3, 4 |
8 |

Telson |
9 |
9 |
9 |
9 |

(Ventral) |

Thorax |
I-II |
4-2 |
A1, 2, M |
6-2 |
A3 |
6-2 |
6-2 |

2 |
P1 |
6 |
P2, 3 |
6 |
6 |

III |
4-2 |
A1, 2, M1 |
6-2 |
A3 |
6-4 |
M2 |
6-4 |

2 |
P1 |
6 |
P2, 3 |
8 |
P2a |
8 |

Abdomen |
I |
4 |
A1, 2 |
4 |
4 |
4 |

2 |
P1 |
4 |
P2 |
4 |
4 |

II-III |
2 |
A1 |
4 |
A2 |
6 |
A3 |
6 |

4 |
P1, 2 |
4 |
4 |
4 |

IV-VII |
2 |
A1 |
4 |
A2 |
6 |
A3 |
6 |

6 |
P1, 2, 3 |
8 |
P2a |
10 |
P2a’ |
10 |

VIII |
0 |
0 |
2 |
A |
2 |

5 |
Pc,1,2 |
7 |
P1a |
7 |
7 |

IX |
4 |
1, 2 |
6 |
1a |
6 |

X |
4 |
1, 2 |
6 |
1a |

XI |
4 |
1, 3 |
8 |
2, 4 |

Telson |
12 |
12 |
12 |
12 |

Larva II.
Body length 682–884 µm. Head length 128–136 µm; pseudoculus 8 µm long, 7–8 µm wide,
PR
= 16. Foretarsus length 80–81 µm; claw 18–20 µm, TR = 4.1–4.5; empodium 17 µm, EU = 0.9; sensillum
s
19–20 µm. Length of middle tarsus 42–43 µm, length of claw 14 µm, empodium 3 µm long; hind tarsus 55 µm, claw 15–16 µm, empodium 3 µm. Shape and position of foretarsal sensilla same as those of imago; BS = 1.1.
P5
on abdominal tergites II and III displaced anteriorly and at same level with
A4
on III (
Fig. 24H
).
Larva I.
Body length 663–845 µm. Head 104–115 µm long, 79–93 µm wide; pseudoculus indistinct. Foretarsus length 70–80 µm; claw 18–20 µm, TR = 4.0–4.1; empodium 17–18 µm, EU = 0.9–1.0; sensillum
s
18–22 µm. Length of middle tarsus 39–45 µm, length of claw 13 µm, empodium 2–3 µm long; hind tarsus 48–54 µm, claw 14– 15 µm, empodium 2–3 µm. Shape and position of foretarsal sensilla same as those of preceding stages.
Diagnosis.
The present species is similar in many respects to
E. brachychaetum
and
E. yinae
. However, it different from
E. brachychaetum
in sensillum
md
longer than
ml
on the maxillary palpus (
md
as long as
ml
in
E. brachychaetum
), the shape of distinct sensillum
pp
(rudimentary in
E. brachychaetum
), foretarsal sensillum
t3
shorter than
c’
(longer than
c'
in
E. brachychaetum
) and five pairs of anterior setae on abdominal tergite VI (four pairs in
E. brachychaetum
); and from
E. yinae
in the shape of inflated seta
rs
(simple in
E. yinae
) and
P1a
shorter than
P1
on the abdominal tergite I–IV (longer than
P
1
in
E. yinae
)
Chaetotaxic variations observed consisted of the asymmetric absences of
A3
on abdominal tergite II in two maturi juniores and
1a
on the abdominal sternite IX in one maturus junior from Mt. Iwate-san.
Etymology.
The specific name is named in honor of Dr. Hiroshi Tamura, who kindly provided opportunities to survey in Mt. Iwate-san and Mt. Komaga–take,
Iwate Prefecture
, where the specimens examined were collected, and who is my mentor for studies on basal hexapods.
Distribution.
Japan
(Honshu).