Redescription of the larva of Amblyomma oblongoguttatum Koch, 1844 (Acari: Ixodidae) by light and scanning electron microscopy
Author
Barbieri, Fabio S.
Author
Brito, Luciana G.
Author
Barros-Battesti, Darci M.
Author
Famadas, Kátia M.
Author
Labruna, Marcelo B.
Author
Camargo, Luis Marcelo A.
text
Zootaxa
2012
3579
80
88
journal article
10.5281/zenodo.283027
8f6f1dc8-0b75-4972-b1b8-82cb9bb56da2
1175-5326
283027
Amblyomma oblongoguttatum
Koch 1844
, LARVA
(
Fig. 1–10
)
IDIOSOMA:
Dorsal surface
(fig. 4). Length from apices of scapulae to posterior margin of body 0.631 ± 0.020 (0.592–0.662); greatest width 0.618 ± 0.017 (0.588–0.649); outline oval, with 11 festoons.
Setae
: 2 central dorsal pairs (Cd1, Cd2), 8 marginal dorsal pairs (Md1–Md8), with Md1 and Md2 before a large wax gland, present in the segment VIII (WdVIII1), and Md3 pair located on the inner side behind of these glands; Md4 – Md8 pairs posterior to large wax gland, each one on a different festoon. Scutum (
Fig. 4
,
8
): outline subtriangular; length 0.247 ± 0.010 (0.230–0.262) along median line; width 0.400 ± 0.016 (0.377–0.441) at the level of eyes; with few punctuations (
Fig. 8
). Eyes slightly bulging and shallow; cervical grooves distinct extending parallel to the proximities of setae Sc3, but slightly diverging at the end.
Setae
: 3 scutal pairs—Sc1, Sc2, Sc3 (fig. 4, 8).
Ventral surface
(figs. 4, 9): Anal aperture on central portion of opisthosoma.
Setae
: 3 sternal pairs (St1, St2, St3), 2 preanal pairs (Pa1, Pa2), 4 premarginal pairs (Pm1–Pm4), 5 marginal ventral pairs (Mv1–Mv5), and 1 pair anal A1.
GNATHOSOMA:
Dorsal
(figs. 1, 5).
Basis capituli
triangular in outline; length from posterior margin of trochanter to posterior margin of capituli 0.095 ± 0.005 (0.083–0.103), width 0.178 ± 0.003 (0.171–0.183). Posterior margin straight,
cornua
absent. Basis capituli on median line with 1 sensillum pair. Palpal grooves segments well-defined (fig. 5, 6). Palpi length from apices of tibiotarsal segment to posterior margin of trochanter 0.140 ± 0.005 (0.133–0.147), width 0.049 ± 0.002 (0.045–0.054); trochanter length 0.021 ± 0.007 (0.016–0.044), width 0.039 ± 0.002 (0.037–0.043); femur length 0.059 ± 0.003 (0.054–0.064), width 0.047 ± 0.003 (0.041–0.051); genu length 0.062 ± 0.003 (0.056–0.069), width 0.041 ± 0.002 (0.035–0.044). Femur with sensillum near seta Fa1 (
Fig. 1
).
FIGURE 1.
Amblyomma oblongoguttatum
larva. Gnathosoma dorsal (right) and ventral (left) views. Abbreviations: d—dorsal; v—ventral; a—antiaxial; p—paraxial; t—terminal; F—femur; G—genu; Tt—tibiotarsus.
Ventral
(
Figs. 1
,
6
):
Basis capituli
as illustrated. Hypostome – compact, spatulate, length from apices to post hypostomal seta 0.117 ± 0.004 (0.111–0.124), dental formula 2/
2 in
file teeth, apical corona usually with 9 denticles (fig. 7); 1 pair of hypostomal setae (
Ph
1).
Palpal setae
(
Figs. 1
,
5, 6
): 10 setae on tibiotarsus, 6 terminal (Ttt1 – Ttt6), 2 paraxial (Ttp1, Ttp2) and 2 antiaxial (Tta1, Tta2) (fig. 7); 6 genual setae, 1 paraxial (Gp1), 1 antiaxial (Ga1), 3 dorsal (Gd1, Gd2, Gd3), and 1 ventral (Gv1); 6 femoral setae, 1 paraxial (Fp1), 2 antiaxial (Fa1, Fa2), 1 dorsal (Fd1), and 2 ventral (Fv1, Fv2); trochanter 0. LEGS: Coxa I with 2 triangular short spurs, the external slightly larger; coxa II and III each with 1 short triangular spur (
Fig. 9
).
Setae
: 3 on coxa I, 1 anterior (CIa), 1 posterior (CIp) and 1 paraxial (CIpa); coxa II and III, each with 2 setae, 1 anterior (CIIa, CIIIa) and 1 posterior (CIIp, CIIIp). Trochanter lacking spur. Tarsus I length 0.200 ± 0.007 (0.184–0.207), width 0.075 ± 0.004 (0.067 – 0.082).
Setae
(figs. 2, 3, 10): Dorsal,
2 in
dorsal I group (
dI
1,
dI
2); 5 dorsal II (dII1 – dII5); 2 dorsal III (dIII1, dIII2); 2 dorsal IV (dIV1, dIV2); 0 dorsal V; 2 dorsal VI (dVI1, dVI2); Ventral, 2 ventral I (
vI1
,
vI2
),
2 in
II group (
vII1
,
vII2
) and
2 in
III (
vIII1
,
vIII2
); Lateral anterior,
1 in
lateral anterior I group (laI1), and
3 in
laII group (laII1, laII2, laII3); Lateral posterior,
1 in
lateral posterior I group (lpI1) and
3 in
lpII group (lpII1, lpII2, lpII3). Ambulacrum as illustrated (
Fig. 2
,
3
,
10
).
FIGURE 2.
Amblyomma oblongoguttatum
larva. Tarsus I dorsal views. Abbreviations: d—dorsal; a— antiaxial; p—paraxial; la—lateral anterior; lp—lateral posterior.
FIGURE 3.
Amblyomma oblongoguttatum
larva. Tarsus I ventral views. Abbreviations: v—ventral; a— antiaxial; p—paraxial; la—lateral anterior; lp—lateral posterior.
Porotaxy:
Dorsal
(
Fig. 4
): Large wax gland—1 pair located on the lateral margin of the idiosoma, on segment VIII, WdVIII1 (30/30 = 30 idiosomal sides containing the pore/ 30 observed idiosomal sides). Lyrifissures – 11 pairs: 1 pair on segment III, LdIII5 (30/30);
1 in
IV, LdIV2 (29/30);
2 in
V, LdV1 (23/30) and LdV6 (30/30);
1 in
VI, LdVI1 (26/30);
2 in
VIII, LdVIII4 (25/30) and LdVIII6 (25/30);
2 in
IX, LdIX4 (29/30) and LdIX6 (30/30);
2 in
XII, LdXII4 (27/30) and LdXII7 (30/30). Small glands – 28 pairs,
3 in
scutum,
2 in
segment III, SdIII3 (21/30) and SdIII5 (30/30);
1 in
IV, SdIV6 (29/30); and one additional asymmetric small gland on the posterior central margin of the scutum, SdV7 (15/15). In alloscutum, 25 pairs on segments:
1 in
IV, SdIV2 (27/30);
3 in
V, SdV2 (20/30), SdV4 (29/ 30), SdV6 (26/30);
4 in
VI, SdVI1 (23/30), SdVI2 (10/30), SdVI4 (29/30), SdVI6 (27/30);
3 in
VIII, SdVIII4 (29/30), SdVIII6 (29/30), SdVIII7 (27/30);
3 in
IX, SdIX1 (21/30), SdIX2 (29/30), SdIX7 (30/30);
3 in
X, SdX1 (13/30), SdX3 (29/30), SdX5 (11/30), and dorsal fovea (dorsal series 7–30/30);
2 in
XI, SdXI3 (28/30), SdXI7 (30/30);
2 in
XII, SdXII1 (29/30), SdXII7 (29/30);
3 in
XIII, SdXIII1 (30/30), SdXIII3 (28/30), SdXIII5 (27/30);
1 in
XIV, SdXIV1 (27/ 30).
FIGURE 4.
Amblyomma oblongoguttatum
larva. Segmentation model of the idiosoma. Segments are indicated by Roman numbers (III–VI e VIII–XIV) and delimitated by dashed lines (----); series are indicated by Arabic numbers and delimitated by dotted lines (........). Integumentary structures are illustrated.
Ventral
(
Fig. 4
): Large wax glands—4 pairs, one behind each coxa in segments III, IV and V, WvIII1 (30/30), WvIV4 (30/30), WvV5 (30/30); 1 pair located on the 5th. festoon, segment XIII, WvXIII1 (30/30). Lyrifissures—13 pairs on segments:
1 in
IV, LvIV6 (28/30);
1 in
V, LvV6 (30/30);
1 in
VIII, LvVIII5 (26/30);
4 in
IX, LvIX1 (28/30), LvIX3 (30/30), LvIX5 (28/30) and LvIX6 (28/30);
1 in
X, LvX2 (30/30);
1 in
XI, LvXI2 (30/30);
1 in
XII, LvXII3 (30/30);
2 in
XIII, LvXIII2 (30/30) and LvXIII6 (30/30);
1 in
XIV, LvXIV2 (29/30).
Small gland. 21 pairs on segments:
1 in
III, SvIII6 (30/30);
1 in
IV, SvIV6, (30/30);
2 in
V, SvV1 (30/30), SvV5 (29/30);
1 in
VI, SvVI2 (30/30);
1 in
VIII, SvVIII1 (30/30);
3 in
IX, SvIX2 (29/30), SvIX4 (30/30), SvIX4’ (29/30);
3 in
X, SvX1 (30/30), SvX3 (29/30), SvX4 (23/30);
3 in
XI, SvXI1 (30/30), SvXI3 (29/30), SvXI4 (16/30);
2 in
XII, SvXII2 (30/30), SvXII4 (30/30);
2 in
XIII, SvXIII3 (30/30), SvXIII6 (30/30);
2 in
XIV, SvXIV1 (29/30), SvXIV4 (13/ 30).
Asymmetric lyrifissures found at low frequency, LvXIII6 (01/30), and small glands, SdX6 (01/30), SdXII3 (01/ 30), SdXII4 (01/30), SdXIII6 (02/30), and SvVIII4 (01/30).