New species and new records of Tetranychidae (Acarina, Prostigmata) from Thailand
Author
Naing, Htar Htar
Author
Chandrapatya, Angsumarn
Author
Navajas, Maria
Author
Auger, Philippe
text
Zootaxa
2014
3802
2
257
275
journal article
45680
10.11646/zootaxa.3802.2.7
5193b0ea-b3db-4c69-af79-1855315cd176
1175-5326
224595
46CC6320-E468-4193-A5CF-17F05F69CB47
Tetranychus
(
Tetranychus
)
occultaspina
sp. nov.
Naing & Auger
(
Figures 15–32
)
Type-specimens.
Holotype
(male),
5 male
and
7 female
paratypes
on 13 preparations from
Ipomoea aquatica
Forssk
, (
Convolvulaceae
), Kasetsart University campus, Khet Bangkhen, Bangkok,
Thailand
,
05/08/2011
, Leg. H. H. Naing.
Holotype
,
3 male
and
5 female
paratypes
deposited in the Insect museum of Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok 10900,
Thailand
;
2 males
and
2 females
deposited in the collection of the CBGP, coll. Auger-Migeon N°
1821–1824
, 34988 Montferrier-sur-Lez,
France
.
Diagnosis.
This species is a
Tetranychus
sensu
stricto
assigned into the ninth group as defined by
Flechtmann and Knihinicki (2002)
. Females bear four tactile setae proximal to the proximal pair of duplex setae and the female empodia are without a dorsomedian spur. Among
Tetranychus
(
T
.) belonging to this group, this species is distinctive by the shape of the aedeagus which has a shaft slightly upturned ending in a knob whose axis forms an acute angle with the shaft’s axis.
Description. Male
:
Holotype
(415 µm long including gnathosoma). Five
paratypes
measured, 400–425 µm long, (including gnathosoma).
Dorsum. Dorsal body setae long, linear lanceolate, well surpassing in length distance between consecutive bases (length of
holotype
and variations of 5
paratypes
):
v
2 48
(48–53);
sc
1 105 (99–107);
sc
2 69 (69–74);
c
1 93 (91–100);
c
2 94 (78–96);
c
3 81 (77–82);
d
1 94 (87–94);
d
2 95 (91–95);
e
1 87
(82–86);
e
2 89
(89–93);
f
1 63 (56–69);
f
2 45 (43–48);
h
1 26 (23–27). Dorsal striae without lobes.
FIGURES 15–16
.
Tetranychus
(
T.
)
occultaspina
sp. nov.
, female. 15, dorsal aspect; 16, triangular lobes on dorsal striae.
Gnathosoma. Palptarsus terminal sensillum about 2.5 times as long as broad, 5.5–6 µm long, 2.3–2.6 µm wide. Peritreme hooked distally.
Venter. Ventral striae without lobes.
Legs. Empodium I bifid, each side composed of one claw-like digit. Large mediodorsal spur present, about three-quarters length of empodium, difficult to see in perfect lateral view because concealed by empodial claws. Empodia II, III and IV without dorsal spurs and with three pairs of proximoventral hairs. Leg setal counts as follows:
FIGURES 17–22
.
Tetranychus
(
T.
)
occultaspina
sp. nov.
, male. 17, tarsus and tibia I; 18, tarsus and tibia II; 19, empodium I in a perfect lateral view; 20, 21, empodium I not in a full lateral view; 22, empodia II–IV.
FIGURES 23–25
.
Tetranychus
(
T.
)
occultaspina
sp. nov.
, male. 23, peritreme; 24, palptarsus; 25, aedeagi (variations).
I 2 − 1 − 10
[9] − 5 − 9 + (4) – 13 + (3) + 2 duplexes;
II 2 − 1
– 6 – 5 – 7 − 13 + (1) + 1 duplex;
III 1 − 1
− 4 − 4 – 6 – 9 + (1);
IV 1 − 1
− 4 − 4 – 7 − 10 + (1).
Aedeagus. Aedeagus shaft gradually narrows distally, slightly upturned. Neck short and wide, aedeagal knob axis forming an acute angle about 50° with shaft axis (range 43° – 52°,
5 males
measured). Knob large 4.2 (3.9–4.3 µm), on average 1.7 times neck width 2.9 (2.1–2.9 µm), asymmetrical with poorly developed posterior rounded projection and well-developed anterior rounded projection anterodorsally directed. Knob dorsal margin undulate.
Female
:
5 females
measured. Idiosoma: length 505–544 µm (including gnathosoma), width 334–342 µm.
Dorsum. Dorsal body setae lanceolate, longer than distances between bases of consecutive setae (variations of 5
paratypes
):
v
2 60
–74;
sc
1 138–156;
sc
2 104–114;
c
1 134–148;
c
2 126–142;
c
3 118–126;
d
1 134–152;
d
2 132–142;
e
1 126–134;
e
2 130–142;
f
1 112–120;
f
2 96–100;
h
1 42–46. Propodosomal striation longitudinal with rounded and oblong lobes becoming triangularly rounded and triangular near dorsohysterosomal setae. Hysterosomal striation transverse except between setae
e
1-
e
1 and
f
1-
f
1 (longitudinal) bases forming diamond-shaped pattern between these setae, with lobes triangular, as tall as broad to taller than broad.
Gnathosoma. Palptarsus spinneret about one and a half as long as broad. Peritreme hooked distally.
Venter. Ventral striation with rounded lobes, broader than tall, few oblong lobes also present. Area immediately anterior to genital flap with broken longitudinal striation, becoming dotted striation medially. Genital flap with transverse slightly arched striae. One pair of ventrocaudal (
h
3) and two pairs of pseudanal setae (
ps
1-2) present.
FIGURES 26–28
.
Tetranychus
(
T.
)
occultaspina
sp. nov.
, female. 26, tarsus and tibia I; 27, tarsus and tibia II; 28, empodium.
FIGURES 29–32
.
Tetranychus
(
T.
)
occultaspina
sp. nov.
, female. 29, flap and anterogenital area; 30, lobes on ventral striation; 31, palptarsus; 32, peritreme.
Legs. Empodia I–IV bear three pairs of proximoventral hairs and no spur was observed. Leg setal counts as follows:
I
2 − 1 − 10 − 5 − 9
+ (1–3) – 13 + (1–3) + 2 duplexes;
II 2 − 1
– 6 – 5 – 7 − 13 + (1) + 1 duplex;
III 1 − 1
− 4 − 4 – 6 – 9 + (1);
IV 1 − 1
− 4 − 4 – 7 − 10 [9–11] + (1).
Tarsus I with four tactile setae and up to two additional solenidia proximal to proximal duplex setae. One solenidion at or near proximal duplex level. Tibia I with up to three solenidia instead of one as usually observed in this group.
Etymology.
The species designation, “
occultaspina
”
, is taken from Latin adjective and noun meaning hidden spine, and refers to the spur of male empodium I which is difficult to see when the empodium is observed in a perfect lateral view.
Biological observations.
The adult females are red in colour to dark red, darkening with age and produce silk. The adult males are yellowish brown and the eggs are pale amber in colour turning into dark orange/brownish-red before hatching.
Remarks.
Among the
Tetranychus
of the 9th group defined by
Flechtmann and Knihinicki (2002)
(including ungrouped species that bear four tactile setae proximal to the proximal duplex setae on tarsus I), the aedeagus of
T. occultaspina
is quite close to those of
Tetranychus bellottii
Flechtmann
,
Tetranychus neocaledonicus
André
,
Tetranychus puschelii
Meyer
,
Tetranychus afrindicus
Nassar & Ghai
,
Tetranychus papayae
Nassar & Ghai
and
Tetranychus ismaili
Yusof & Zhang.
Tetranychus occultaspina
can be distinguished from
T. bellottii
by its anterior aedeagal angulation which is rounded
vs.
acute in
T. bellottii
and by the angle formed between the knob’s axis and the shaft’s axis, which is greater in
T. occultaspina
.
The aedeagus of
T. occultaspina
differs from those of
T.
neocaledonicus
and
T. puschelii
by the shape of its aedeagal knob which is more flattened with a dorsal margin not indented but undulated. It can be separated from
T. afrindicus
and
T. papayae
according to the shape of its aedeagal anterior projection which is rounded whereas it is angulate in the two others species and by the angle formed between the knob axis and the shaft’s axis. In
T. ismaili
aedeagal projections are acute whereas rounded in
T. occultaspina
.
Additional solenidia are sometimes present on tibia I and tarsus I of
T. occultaspina
: one to two on tarsus I (proximal to the proximal duplex) and one to two on tibia I. This unusual chaetotaxy is not specific to
T. occultaspina
. Indeed, hypertrichous forms have already been reported in some strains of
Tetranychus
species belonging to the 9th group (
Auger
et al.
2013
). It is known to occur in the two colour forms (green and red) of
Tetranychus urticae
Koch
and also in
Tetranychus gloveri
Banks
(e. g.
McGregor (1950)
;
Boudreaux (1956
,
1958
);
Zhang & Jacobson (2000))
.