Hidden diversity of endoparasitic eriophyoid mites: two new Novophytoptus Roivainen, 1947 (Acari: Eriophyoidea: Phytoptidae) species from the parenchymatous tissues of rushes (Juncaceae)
Author
Chetverikov, Philipp E.
text
Zootaxa
2015
4006
3
481
505
journal article
10.11646/zootaxa.4006.3.4
bfbc9b10-66fa-40d0-a1b2-bc4458587fce
1175-5326
239377
D01B5A31-9D9E-4C50-9443-101EDB3E04C3
Novophytoptus maritimus
n. sp.
(
Figs. 5
J–R, 10, 11, 12)
Female
(n=9:
holotype
&
paratypes
). Idiosoma vermiform, 312 (275–339), 43 (49–47) wide at level of setae
c2
, 49 (44–55) wide at level of setae
f
.
Prodorsal shield
(
Figs. 5
J–R, 10) subpentagonal, 31 (28–35)
x 21
(18–22) wide, with two ocella-like spots lateral to setae
ve
. Anterior margin of prodorsal shield acuminate, forming a short triangular lobe. Shield ornamentation with complete entire median line and admedian lines from rear to anterior shield margin. In posterior half of shield, admedian lines curved, forming a bulb-shaped figure. Two thin, submedian-1 lines running parallel to admedian lines in anterior half of shield with five distinct thin lines seen in well-mounted specimens, usually parallel and not convergent; several additional indistinct longitudinal wrinkles or ridges sometimes seen lateral to the five median lines; two or three thin lines present between tubercles
ve
and anterior “bottle”. Rudimentary medioposterior fovea (“pit”
sensu
Keifer) surrounded by small scattered lines present on rear prodorsal shield margin. Area between tubercles of
sc
smooth; a group of about 30–35 circular/oval granules anteriorly to each
sc
tubercle. Setae
ve
15 (12–16), directed anterolaterad, tubercles 10 (9–12) apart;
sc
74 (68–84), directed posterolaterad, tubercles 15 (15–19) apart. Distance between tubercles
ve–sc
20 (17–23).
Gnathosoma
elongate, directed forward and slightly ventrad, 31 (31–38); pedipalp coxal seta
ep
4 (3–6), pedipalp genual seta
d
absent, subapical pedipalp tarsal seta
ν
0.5 (0.5–1). Basal gnathosoma covered by seemingly smooth suboral plate.
Leg
I
36 (34–40), tibia 12 (10–14),
l'
6 (5–7), tarsus 5 (5–6),
u ′
2 (1–2),
ft ′
3 (3–3),
ft″
14 (14–18);
ω
5 (5–7), without knob; empodium 4/4-rayed, 7 (6–8), each ray of the three basal pairs with one or two tiny secondary branches, terminal paired rays without additional branching, of equal length, situated on rod-like shaft, thus remote from other rays (
Figs. 5
O, 11B).
Leg
II
32 (31–35), tibia 8 (8–9), tarsus 4 (4–6),
u
1 (1–2),
ft ′
2 (2–5),
ft″
23 (21– 24);
ω
11 (9–13), without knob; empodium 4/4-rayed, 9 (9–10), each ray of the three basal pairs with one or two tiny secondary branches, terminal paired rays without additional branching, internal terminal ray 5–7 times longer than external ray (
Figs. 5
Q, 11B).
FIGURE 10.
DIC images showing variation of prodorsal shield ornamentation in females (
A −G
) and males (
H
,
I
) of
Novophytoptus maritimus
n. sp.
Scale bar:
A–I
= 15 Μm.
FIGURE 11.
DIC images of legs and tarsal appendages of normal (
A
,
B
) and aberrant (
C
,
D
) females of
Novophytoptus maritimus
n. sp.
А
—dorsal view of leg I and II on the level of
ω
I and II in focus;
B
—empodia I and II (same mite as on Fig.
A
);
C
,
D
—aberrant tarsus I, with
ω
I displaced medially and seta
ft’
short and stout.
Note
: on Fig. C tarsus is coloured in red and tibia is coloured in green. Scale bar:
A
= 15 Μm;
B
= 10 Μm;
C
,
D
= 5 Μm.
Coxae
ornamented with several lines. Prosternal apodeme faint, inversely T-shaped, extending from rear margin of suboral plate to past level of
1a
tubercles. Setae
1b
15 (10–19), 12 (11–13) apart;
1a
35 (25–38), 7 (6–8) apart;
2a
50 (33–60), 20 (18–23) apart; 12 (12–16) complete and 1 (1–2) incomplete (i.e. segregated from lateral annuli) coxigenital annuli before epigynium.
Genital coverflap
semi-circular, smooth, 9 (8–10)
x 16
(15–18) wide; setae
3a
notably thickened, 12 (11–15), 14 (14–18) apart.
FIGURE 12.
DIC images of genital region of
Novophytoptus maritimus
n. sp.
showing difference in the thickness of opisthosomal setae in females (
A
,
B
) and males (
C
). Scale bar = 15 Μm.
Opisthosoma
vermiform (nearly parallel-sided for most of length), slightly expanded caudally: widest at level of
f
tubercles; dorsal and ventral annuli bearing small, elongated microtubercles, last 6 (5–7) dorsal annuli without microtubercles. Setal lengths:
c2
29 (23–29),
d
18 (17–25),
e
14 (12–15),
f
14 (14–18),
h1
7 (5–9),
h2
87 (80–115); 10 (10–13) annuli from rear shield margin to
c2
; 15 (12–17) annuli between
c2–d
; 17 (16–20) annuli between
d
and
e
; 31 (28–36) annuli between
e
and
f
; 7 (6–7) annuli between
f
and
h1
. Opisthosomal setae
c2
,
d
,
e
and
f
notably thickened (
Fig. 12
A, B).
Remarks
. One aberrant female of
N. maritimus
n. sp.
(slide #u1/3-12) had a shortened and expanded tarsus on Leg I, which was fused with the tibia (
Fig. 11
C,D). The tarsal solenidion
ω
I was displaced medially and seta
ft ′
I was shortened and thickened. It appears that mutants (Figs. 8; 11 C,D) are common in populations of novophytoptines. This may be the result of inbreeding within the mite colonies which are isolated under the epidermis.
Male
. Only one male specimen in good condition was available for measurement. In comparison to females, this male was wider (at the level of tubercules
c2
and
f
); had shorter setae
sc
,
1a
,
2a
,
h2
; with tarsal solenidia
ω
I, II, opisthosomal setae
c2
,
d
,
e
and
f
of common thickness (
Fig. 12
C); with more annuli (45) between tubercules
e
and
f
(
Table 1
). The external genitalia were cone-shaped, with two posterior flaps and anterior papilla-like protuberance (translucent in slidemounts) and eugenital setae seemingly absent (
Fig. 12
C). Remarkably, rather short
em
I, II (about 3 µm) with all rays of equal length were observed (
Fig. 5
N). In females, these are much longer (7 and 10 µm respectively) and have one or two elongated terminal rays (
Fig. 5
O,Q).
Host plant
.
Juncus maritimus
Lam.
(sea rush): distributed in Azores, Europe to Central Asia (
Govaerts 2014
)
Relation to host
. Mites live in air cavities of parenchymatous tissues (aerenchyma) inside the stems.
Type
material
. Female
holotype
(encircled by black marker) on slidemount #u1/2-12.
Paratypes
:
18 specimens
(nine females, four males and five immatures) on slidemounts #u1/1-12, #u1/2-12 and #u1/3-12. All specimens from
UKRAINE
: Zaporozhye Prov., Kirillovka, 46°18′32″N, 35°18′30″E,
16 September 2012
, coll. T.G. Chetverikova.
Etymology
. The specific epithet,
maritimus
, is a masculine singular adjective corresponding to the specific name of the host-plant.
Differential diagnosis
. The new species is close to
N. luzulis
n. sp.
(described above). Females of these two species differ in the length of the gnathosoma (longer in
N. maritimus
), length of
sc
(shorter in
N. maritimus
), length of
ω
II and
em
II (longer in
N. maritimus
), thickness of setae
c2
,
d
,
e
and
f
(notably thicker in
N. maritimus
), number of dorsal and ventral annuli (both more numerous in
N. maritimus
), prodorsal shield ornamentation and shape of terminal rays of empodia I and II (
Table 4
).
TABLE 4.
Differences between females of
Novophytoptus maritimus
n. sp.
and
N. luzulis
n. sp.
Character Mite species