Edaphic ascid mites (Acari: Mesostigmata: Ascidae) from the state of São Paulo, Brazil, with description of five new species
Author
De, Jeferson L.
Author
Lindquist, Evert E.
Author
De, Gilberto J.
text
Zootaxa
2009
2024
1
32
journal article
10.5281/zenodo.186138
8cf8a401-bc91-4a30-99b8-27492f4f254e
1175-5326
186138
Protogamasellus sigillophorus
sp. nov.
(
Figs 60–67
)
Diagnosis:
Adult females of this species are similar to those of
Protogamasellus massula
(
Athias-Henriot, 1961
)
and
P
.
scuticalis
Genis
et al
.,
1967
in having opisthogastric setae
ZV1
inserted behind, and in longitudinal alignment with,
JV1
on soft cuticle and in having a pyriform ventri-anal shield that is longer than wide, with 3 pairs of opisthogastric setae (
JV2
,
JV3
and
JV5
) in addition to the circum-anal setae. They differ from the latter two in a variety of aspects, particularly the opisthonotal shield having setae
J4
relatively short (i.e., only 1.3 instead of 2.0 longer than
J5
), and the simply bidentate movable digit, with the proximal tooth much larger than the subapical tooth.
FIGURES 60–67.
Protogamasellus sigillophorus
n. sp.
Adult female, dorsal idiosoma (60), ventral idiosoma (61), tectum (62), chelicera (63), ventral
gnathosoma
(64), ventral tarsus II (65), dorsal tarsus II (66) and tibia and tarsus IV (67).
Adult female
.
Dorsal idiosoma
(
Fig. 60
): Dorsal shields collectively 270–305 µm long and unornamented other than podonotal shield having an uninterrupted transverse line at level of setal bases
z6
and
s6
, behind which shield desclerotized, and opisthonotal shield having an uninterrupted transverse line at level of setal bases
J1
, followed by a couple of short transverse lines laterally near bases of setae
Z1
and
S1
and a median sigillar scar between bases of setae
J1
and
J2
. Podonotal shield 130–148 µm long, 98–102 µm wide at level of setae
j5
, with 17 pairs of setae, opisthonotal shield 138–152 µm long, 65–68 µm wide at level of setae
J2
, (
ca
. 2.1–2.2 times as long as wide) with 15 pairs of setae; 12 pairs of setae on lateral soft cuticle, including
s2
and
r2-r5
anteriorly (
r6
absent) and
R1-R6
and one submarginal
UR
seta posteriorly. Podonotal shield with vertical setae
j1
prominent, stouter and longer (25–27 µm) than other setae (11–16 µm) which shorter than successive distances between their bases; on opisthonotal shield
J3
(12–14 µm)
ca
. 0.3–0.4 times as long as alveolar interval
J3-J4
,
J5
(9–10 µm) shorter than other members of
J
-series (12–16 µm),
Z1-Z4
similar in length (15–18 µm) and 0.6–0.7 as long as alveolar interval to next seta in series,
Z5
conspicuously longer (28–30 µm);
S1-S4
similar in length (11–12 µm) and 0.4–0.5 as long as interval to next seta in series,
S5
slightly longer (14 µm); all setae smooth except
J4
,
Z5
and
S5
sparsely barbed. Setae
j2
transversely aligned with
j1
and
z1
. Setae on lateral soft cuticle short (10–13 µm, except
r3
15 µm), simple.
Ve n t ra l idiosoma
(
Fig. 61
): Tritosternum normal in shape, with trapezoidal base and slender, pilose laciniae fused along basal one-fifth of their length (60–70 µm). Pre-sternal area weakly sclerotized, microtuberculate, without platelets. Sternal shield
ca
. 75 µm in median length by 45 µm wide at narrowest width between coxae II, with 3 pairs of setae and 3 pairs of poroids; shield with anterior margin deeply emarginated medially, faintly lineated along lateral margins, smooth over rest of surface, and with posterior margin gently concave. Setae
st4
inserted on soft cuticle closely behind postero-lateral corners of sternal shield,
st4
and genital setae
st5
(10–12 µm) slightly shorter than sternal setae
st1-st3
(14–16 µm). Endopodal plates formed as weak strips alongside coxae III–IV, not discernible in some specimens. Genital shield smooth, not widened at level of insertions of genital setae, with posterior margin truncate, and hyaline anterior margin broadly rounded, reaching posterior margin of sternal shield. Post-genital groove without discernible sigillar platelets. Metapodal plates hardly discernible as short, narrow strips (length 10 µm) laterad
JV1
. Ventri-anal shield pyriform,
ca
. 1.2 as long (87–97 µm) as wide (65–75 µm), with anterior margin arched; with 2 or 3 transverse lines arched anteriorly between bases of setae
JV2
and para-anals (lines sometimes interrupted medially), and sparsely punctate on post-anal region; shield with 3 pairs of ventral setae (
JV2
,
JV3
,
JV5
) plus 3 circum-anal setae; post-anal seta and
JV5
sparsely barbed and considerably longer (33–36 µm and 21–23 µm, respectively) than smooth para-anals (14–16 µm) and
JV2-JV3
(11–14 µm); para-anals inserted at level of anterior margin of anus. Three pairs of ventral setae (
JV1
,
ZV1
,
JV4
) on soft cuticle anterior and lateral to ventri-anal shield;
ZV1
nearly aligned vertically behind
JV
1
in front of anterior margin of shield. Exopodal plate strips reduced to triangular fragments between coxae II and III, and between coxae III and IV, not discernible in some specimens.
Peritrematal shield and peritreme
(
Fig. 60–61
): Peritrematal shield interrupted between levels of setal alveoli
r3
and
s2
, with separate triangular anterior piece abutting but not fused to dorsal shield at level of paravertical poroids and setae
z1
; peritrematal shield narrow posteriorly, not fused to exopodal fragments alongside coxae II–IV; peritremes extending to bases of setae
r3
.
Spermathecal apparatus
: Unsclerotized, not discernible in specimens at hand.
Gnathosoma
(
Figs 62–64
): Anterior margin of tectum denticulate, irregularly triangular. Fixed digit of chelicera with
pilus dentilis
, with large offset subapical tooth and row of 11–13 evenly sized and spaced teeth; movable digit 35 µm long, with 2 well separated, slightly retrorse teeth, the proximal larger than subapical one. Deutosternum with 7 narrow, connected rows of denticles, anteriormost 2 or 3 rows with single median denticle, other rows with 2–4 denticles; corniculus stout, reaching to mid-level of palpfemur; internal mala slender, with lateral margin slightly fimbriate, hardly widened basally, extending to tips of corniculus. Hypostomatic setae
h1
(20 µm) similar in slender form to, but longer than,
h2
(15 µm). Palptrochanter with apical seta slightly stout, rigid, inserted on low prominence.
Legs
(
Figs 61, 65–67
): Leg I (268–275 µm) nearly as long as combined length of the 2 dorsal shields; legs II (163–168 µm), III (132–140 µm) and IV (200–212 µm) considerably shorter, with III notably smaller than II. Coxa I with cluster of 2–4 small spine-like processes on dorsal distal margin, and sparsely lineate ventrally; coxa II with 2 lines posteroventrally; coxae III–IV unornamented (processes and lines of coxae I and II not shown in
Fig. 61
). Legs I–IV with normally developed pretarsi (length
ca
. 5 µm on I, 8–11 µm on II–IV) and claws. Tarsi II–IV with apical setal processes
ad -1
,
pd -1
inconspicuous, thin (length ca. 10 µm). Leg IV with tarsus (47–50 µm)
ca
. 2.3 as long as tibia (35–38 µm); tarsus IV with seta
ad -2
(also denoted as
md
) (22 µm) and
ad -3
(27–30 µm) erect and longer than other setae on same segment (
Fig. 67
). Setation of femora of legs I-II-III-IV, respectively,
12-11-6-6
; that of genua,
13-11-8-8
(
pv -1
absent on genu III,
pl -1
absent on genu IV); that of tibiae,
13-10-8-9
(
pl -2
absent on tibia IV); leg setae smooth, mostly slender, except
ad -3
on femur I,
ad -2
,
ad -3
on femur II, and
ad -2
,
pd -1
,
pl -1
of femur IV short, spine-like, and
av -2
, to lesser extent other ventral setae on tarsus II (
Fig. 65
) and
av -2
,
pv -2
,
mv
on tarsus IV thickened, spinelike (
Fig. 67
).
Adult male
: Unknown.
Material examined:
Holotype
female collected,
2.x.1998
, from soil of a corn field, ESALQ-USP, Piracicaba, State of São Paulo, col. J.L. de C. Mineiro, deposited at ESALQ-USP. Three
paratype
females including two with same data as
holotype
and one with same data except that collected on
21.xii.1998
, two deposited at
ESALQ
/
USP
and one deposited at
CNCI
.
Remarks:
Our description of this species as distinct from
P
.
massula
is based in part on notes taken by one of us (EEL, unpublished, 1972) during a study of Athias-Henriot’s
type
material as well as on the subsequent redescription of that species by
Evans (1982)
. The setal deficiencies noted for genua III–IV and tibia IV in the above description are typical for the leg chaetotaxy of the genus
Protogamasellus
as indicated by
Lindquist & Evans (1965)
and further noted by
Evans (1982)
.
Etymology:
The name
sigillophorus
refers to the presence of median sigillar scar between the bases of setae
J1
and
J2
.