Revision of torrent mites (Parasitengona, Torrenticolidae, Torrenticola) of the United States and Canada: 90 descriptions, molecular phylogenetics, and a key to species
Author
Fisher, J. Ray
Author
Fisher, Danielle M.
Author
Skvarla, Michael J.
Author
Nelson, Whitney A.
Author
Dowling, Ashley P. G.
text
ZooKeys
2017
701
1
496
http://dx.doi.org/10.3897/zookeys.701.13261
journal article
http://dx.doi.org/10.3897/zookeys.701.13261
1313-2970-701-1
23BDD7CE1C7E4D2092A8ED47267579FD
23BDD7CE1C7E4D2092A8ED47267579FD
Torrenticola gnoma Fisher & Dowling
sp. n.
Material examined.
HOLOTYPE (♀): from USA, Mississippi, Attala County, Hurricane Creek (
33°4'57"N
,
89°31'29"W
), 12 Sep 2008, by IM Smith, IMS080052.
PARATYPES (6 ♀; 10 ♂): Georgia, USA: 1 ♂ from Lowndes County, Withlacoochee River, beside Route 84 at Brooks County line, 13 Sep 1968, by DR Cook, DRC680075
*
Illinois, USA: 1 ♀ and 2 ♂ from Clark County, Big Creek (
32°25'59"N
,
87°41'15"W
), 30 Jul 2014, by MJ Skvarla, MS 14-0730-001
*
1 ♂ from Vermilion County, Fairmount, beside Vermilion County Road 680E, Jordan Creek (40°4'N, 87°50'W), 10 Sep 1991, by IM Smith, IMS910030
*
Mississippi, USA: 1 ♂ (ALLOTYPE) from USA, Mississippi, Attala County, Hurricane Creek (
33°4'57"N
,
89°31'29"W
), 12 Sep 2008, by IM Smith, IMS080052
*
1 ♀ and 1 ♂ from Attala County, Hurricane Creek (
33°4'58"N
,
89°31'31"W
), 30 Sep 2010, by IM Smith, IMS100168
*
1 ♀ and 1 ♂ from Grenada County, Leflore, beside Black Creek Road, Black Creek (
33°43'N
,
90°3'W
), 16 Sep 1991, by IM Smith, IMS910044
*
1 ♀ and 1 ♂ from Jefferson County, off Natchez Trace Parkway, Coles Creek (
31°41'26"N
,
91°10'52"W
), 2 Oct 1994, by IM Smith, IMS940029A
*
1 ♀ and 1 ♂ from Tishomingo County, Tishomingo State Park, Bear Creek, (
34°36'N
,
88°11'W
), 18 Sep 1991, by IM Smith, IMS910047A
*
Oklahoma, USA: 2 ♀ and 2 ♂ from Pushmataha County, beside Route 271, South of Albion, Walnut Creek (
34°39'N
,
95°7'W
), 1 Jul 1987, by IM Smith, IMS870063A.
Type deposition.
Holotype (♀), allotype (♂), and some paratypes (4 ♀; 5 ♂) deposited in the CNC; other paratypes (2 ♀; 3 ♂) deposited in ACUA.
Diagnosis.
Torrenticola gnoma
are similar to other members of the Raptor Group (
T. irapalpa
,
T. longitibia
,
T. mjolniri
,
T. elusiva
,
T. racupalpa
,
T. raptor
,
T. danielleae
,
T. daemon
, and
T. ivyae
) in having round bodies; Dgl-4 close to muscles scars; long, thin subcapitular rostra; and long, thin pedipalp tibiae.
T. gnoma
can be differentiated from
T. elusiva
by being smaller (dorsum length = 540-595 in
T. gnoma
, 645 in
T. elusiva
); having a stockier rostrum (length/width = 2.74-3.13 in
T. gnoma
, 3.65 in
T. elusiva
); and by dorsal coloration.
T. gnoma
can be differentiated from
T. racupalpa
by having a stockier rostrum (length/width = 2.74-3.13 in
T. gnoma
, 3.56-3.88 in
T. racupalpa
) and by dorsal coloration and pattern.
T. gnoma
can be differentiated from
T. irapalpa
,
T. danielleae
, and
T. daemon
by dorsal coloration and pattern. Additionally, female
T. gnoma
can be differentiated from female
T. irapalpa
,
T. danielleae
, and
T. daemon
by having Dgl-4 closer to the muscle scars (dorsal width/distance between Dgl-4 ♀ = 2.65-3.29 in
T. gnoma
, 1.57-2.09 in others).
T. gnoma
can be differentiated from
T. mjolniri
,
T. longitibia
,
T. raptor
, and
T. ivyae
by having stockier pedipalp tibiae (length/width = 3.88-4.67 in
T. gnoma
, 4.75-7.54 in others) and a stockier rostrum (length/width = 2.56-3.23 in
T. gnoma
, 3.44-4.4 in others).
Description.
Female (Figure 88) (n = 5) (holotype measurements in parentheses when available) with characters of the genus with following specifications.
Dorsum - (540-595 (550) long; 440-500 (455) wide) circular with a large spot of coloration medially extending in a thin strip anteriorly to the edge of the dorsal plate, coloration variable from navy blue to purple to pink. Anterio-medial platelets (122.5-137.5 (131.25) long; 55-62.5 (60) wide). Anterio-lateral platelets (152.5-187.5 (167.5) long; 67.5-75 (70) wide) free from dorsal plate. Dgl-4 much closer to the muscle scar than to dorsum edge (distance between Dgl-4 140-185 (155)). Dorsal plate proportions: dorsum length/width 1.17-1.30 (1.21); dorsal width/distance between Dgl-4 2.65-3.29 (2.94); anterio-medial platelet length/width 2.06-2.39 (2.19); anterio-lateral platelet length/width 2.26-2.59 (2.39); anterio-lateral/anterio-medial length 1.11-1.46 (1.28).
Gnathosoma - Subcapitulum (285-305 (290) long (ventral); 225-239 (226) long (dorsal); 115-135 (120) tall) colorless. Rostrum (122.5-130 (125) long; 40-47.5 (40) wide) elongate. Chelicerae (285-310 (286) long) with curved fangs (53-60 (54) long). Subcapitular proportions: ventral length/height 2.26-2.52 (2.42); rostrum length/width 2.74-3.13 (3.13). Pedipalps elongate with tuberculate ventral extensions on femora and genua. Palpomeres: trochanter (40-45 (40) long); femur (110-120 (112.5) long); genu (60-67.5 (62.5) long); tibia (87.5-105 (92.5) long; 20-22.5 (20) wide); tarsus (17.5-20 (17.5) long). Palpomere proportions: femur/genu 1.63-1.88 (1.80); tibia/femur 0.76-0.88 (0.82); tibia length/width 4.17-4.67 (4.63).
Venter - (660-730 (680) long; 500-575 (500) wide) colorless. Gnathosomal bay (142.5-172.5 (152.5) long; 75-92.5 (75) wide). Cxgl-4 subapical. Medial suture (15-27.5 (27.5) long). Genital plates (152.5-165 (157.5) long; 142.5-152.5 (142.5) wide). Additional measurements: Cx-1 (252-285 (257) long (total); 84-122 (108) long (medial)); Cx-3 (317-377 (318) wide); anterior venter (160-167.5 (165) long). Ventral proportions: gnathosomal bay length/width 1.57-2.16 (2.03); anterior venter/genital field length 0.97-1.10 (1.05); anterior venter length/genital field width 1.05-1.16 (1.16); anterior venter/medial suture 6.00-10.67 (6.00).
Male (Figure 89) (n = 5) (allotypic measurements in parentheses when available) with characters of the genus with following specifications.
Dorsum - (420-495 (450) long; 355-375 (375) wide) circular with a large spot of coloration medially extending in a thin strip anteriorly to the edge of the dorsal plate, coloration variable from navy blue to purple to pink. Anterio-medial platelets (1.80-2.30 (2.18) long; 50-62.5 (55) wide). Anterio-lateral platelets (135-152.5 (152.5) long; 60-65 (60) wide) free from dorsal plate. Dgl-4 much closer to the muscle scar than to dorsum edge (distance between Dgl-4 130-180 (165)). Dorsal plate proportions: dorsum length/width 1.17-1.32 (1.20); dorsal width/distance between Dgl-4 2.06-2.73 (2.27); anterio-medial platelet length/width 1.80-2.30 (2.18); anterio-lateral platelet length/width 2.16-2.54 (2.54); anterio-lateral/anterio-medial length 1.17-1.36 (1.27).
Gnathosoma- Subcapitulum (240-265 (265) long (ventral); 175-196 (196) long (dorsal); 97.5-105 (105) tall) colorless. Rostrum (98.75-107.5 (107.5) long; 35-40 (35) wide) elongate. Chelicerae (225-257 (256) long) with curved fangs (41-51 (50) long). Subcapitular proportions: ventral length/height 2.29-2.56 (2.52); rostrum length/width 2.56-3.07 (3.07). Pedipalps elongate with tuberculate ventral extensions on femora and genua. Palpomeres: trochanter (35-47.5 (47.5) long); femur (96.25-103.75 (103.75) long); genu (52.5-57.5 (57.5) long); tibia (77.5-90 (88.75) long; 20-22.5 (20) wide); tarsus (17.5-20 (18.75) long). Palpomere proportions: femur/genu 1.72-1.83 (1.80); tibia/femur 0.81-0.91 (0.86); tibia length/width 3.88-4.44 (4.44).
Venter - (560-590 (581) long; 354-440 (395) wide) colorless. Gnathosomal bay (105-130 (127.5) long; 62.5-77.5 (62.5) wide). Cxgl-4 subapical. Medial suture (67.5-80 (70) long). Genital plates (122.5-135 (127.5) long; 100-110 (105) wide). Additional measurements: Cx-1 (217-269 (255) long (total); 90-119 (115) long (medial)); Cx-3 (264-312 (295) wide); anterior venter (197.5-222.5 (207.5) long). Ventral proportions: gnathosomal bay length/width 1.40-2.04 (2.04); anterior venter/genital field length 1.49-1.65 (1.63); anterior venter length/genital field width 1.80-2.12 (1.98); anterior venter/medial suture 2.53-2.96 (2.96).
Immatures unknown.
Etymology.
Specific epithet (
gnoma
) refers to the dorsal pattern, which, although variable, resembles the head and cap of a gnome (gnoma, L. diminutive fabled being, dwarf).
Distribution.
Eastern, but apparently absent from Appalachians and Northeast (Figure 87).
Figure 87.
Torrenticola gnoma
sp. n. distribution.
Figure 88.
Torrenticola gnoma
sp. n. female: A dorsal plates B venter (legs removed) C subcapitulum D pedipalp (setae not accurately depicted). Scale = 100
µm
.
Figure 89.
Torrenticola gnoma
sp. n. male: A dorsal plates B venter (legs removed) C subcapitulum D pedipalp (setae not accurately depicted). Scale = 100
µm
.
Remarks.
Torrenticola gnoma
groups with other members of the Raptor Complex with high support and specimens of this species were less than 1% different in COI sequence from each other. In the combined analysis,
T. gnoma
groups with
T. irapalpa
with high support, but the position of this clade was not recovered. These species are greater than 9% from each other. Based upon overall similarity, distribution, and phylogenetic position, this species is placed within the Raptor Identification Group.
This species hypothesis is supported by low COI divergence within the species (0-2%) and high divergence between species (3-15%), and by the morphological characters outlined in the diagnosis.