Torrenticola magnexa Habeeb, 1955

Fisher, J. Ray, Fisher, Danielle M., Skvarla, Michael J., Nelson, Whitney A. & Dowling, Ashley P. G., 2017, Revision of torrent mites (Parasitengona, Torrenticolidae, Torrenticola) of the United States and Canada: 90 descriptions, molecular phylogenetics, and a key to species, ZooKeys 701, pp. 1-496 : 1

Torrenticola magnexa Habeeb, 1955

Torrenticola amplexa magnexa Habeeb, 1955: 4

Torrenticola amplexa neoconnexa Habeeb, 1957: 1 (initially identified as Torrenticola amplexa connexa (Koenike, 1908) in Habeeb 1955: 4)

Torrenticola neoconnexa Habeeb, 1961: 2.

Torrenticola magnexa Habeeb, 1961: 2.

Material examined.

HOLOTYPE (♀): from Canada, New Brunswick, Victoria County, Salmon River, 21 June 1953, by Habeeb, HH530075.

PARATYPES (0 ♀; 1 ♂): New Brunswick, Canada: 1 ♂ (ALLOTYPE) from Victoria County, Salmon River, 21 June 1953, by Habeeb, HH530075.

OTHER MATERIAL (29 ♀; 14 ♂): Maine, USA: 2 ♀ from Franklin County, Smalls Falls Picnic Area, beside Route 4, Sandy River (44°52'N, 70°31'W), 5 Jul 1989, by IM Smith, IMS890069 • Missouri, USA: 1 ♀ from McDonald County, Tiff City, beside Route 43, Buffalo Creek (36°40'17"N, 94°36'17"W), 2 May 1996, by IM Smith, IMS960004 • Nova Scotia, Canada: 1 ♀ from Inverness County, Cape Brenton Highland National Park, 10 Sep 2011, by IM Smith, IMS110072 • 2 ♀ from Inverness County, Inervess, Cheticamp River, 10 Sep 2011, by IM Smith, IMS110071 • New Brunswick, Canada: 1 ♀ and 1 ♂ from Victoria County, St. Quentin, beside Highway 17, 14 km southwest of Highway 180, 14 Sep 2011, by IM Smith, IMS110059 • 2 ♀ from York County, Napadogan, beside Road J-19, 4 km south of Hwy 107, 6 Oct 2011, by IM Smith, IMS110126 • Newfoundland, Canada: 2 ♀ from Crooked Feeder, beside Highway 1, north of Deer Lake (49°10'N, 57°26'W), 25 Jul 1977, by IM Smith, IMS770125B • 1 ♀ and 1 ♂ from Deer Lake, beside Highway 430, 6.2 kilometers north of Highway 1 (49°10'N, 57°26'W), 23 Jul 1977, by IM Smith, IMS770112 • 2 ♀ and 2 ♂ from Molly Chignic Brook, beside Highway 1 (47°51'N, 59°10'W), 7 Oct 1989, by IM Smith, IMS890133 • Ohio, USA: 2 ♂ from Montgomery County, Engelwood Metro Park (39°52'58"N, 84°17'33"W), 31 Jul 2014, by MJ Skvarla, MS 14-0731-002 • Quebec, Canada: 1 ♀ from Gatineau County, Gatineau Park, Meech Lake (45°32'27"N, 75°54'53"W), 27 Jul 2010, by IM Smith, IMS100105 • 2 ♀ and 2 ♂ from Gatineau County, Gatineau Park, tributary above Blanchet Beach, 6 Apr 2012, by IM Smith, IMS120001 • 1 ♀ and 1 ♂ from Gatineau County, Gatineau Park, beside Wolf Trail above Blanchet (45°32'30"N, 75°55'29"W), 12 Jun 2008, by IM Smith, IMS080009A • 1 ♂ from Matane County, St.-Bernard-des-Lacs, Riviere Ste. Anne (48°55'45"N, 66°7'0"W), 25 Aug 1975, by BP Smith, DW Barr, & N Avruch, BPS750562 • 2 ♀ and 1 ♂ from Matapedia County, beside secondary road, Riviere Matapedia (48°17'40"N, 67°15'20"W), 24 Aug 1975, by BP smith, DW Barr, & N Avruch, BPS750557 • 1 ♀ from Stanstead County, Tompkin Stream, Tomifobia River (45°0'31"N, 72°7'6"W), 20 Aug 1996, by IM Smith & M MacKenzie, IMS960056 • Tennessee, USA: 1 ♀ from Blount County, Great Smokey Mountains National Park, Abrams River (35°35'31"N, 83°51'21"W), 17 Sep 2010, by IM Smith, IMS100141 • 1 ♀ from Sevier County, Great Smokey Mountains National Park (35°46'54"N, 83°13'2"W), 16 Sep 2010, by IM Smith, IMS100140 • 1 ♀ from Sevier County, Great Smokey Mountains National Park, middle prong Little Pigeon River (35°42'38"N, 83°22'59"W), 10 Sep 2009, by IM Smith, IMS090106 • Vermont, USA: 2 ♀ and 1 ♂ from Addison County, beside road from Lincoln to Ripton, Middlebury River (44°0'N, 73°1'W), 6 Jul 1989, by IM Smith, IMS890075 • 2 ♀ from Addison County, Lincoln, beside US Forest Service Road #54, New Haven River (44°6'N, 72°59'W), 6 Jul 1989, by IM Smith, IMS890074 • 2 ♀ and 2 ♂ from Lamoille County, Stowe, beside Route 108, West Branch of Waterbury River (44°30'N, 72°46'W), 6 Jul 1989, by IM Smith, IMS890072.

Type deposition.

Holotype (♀) and allotype (♂) deposited in the CNC.

Diagnosis.

Torrenticola magnexa are similar to other members of the Partial 2-Plate Group ( T. folkertsae , T. pulchra , and T. priapus ) in having anterio-lateral platelets partially fused to the dorsal plate and being distributed in the east. T. magnexa can be differentiated from other Partial 2-Plate Group by dorsal coloration and pattern. T. magnexa can be further differentiated from T. New 23A by having a less elongate rostrum (length/width = 2.25-3.00 in T. magnexa , 3.17-3.39 in T. priapus ). T. magnexa can be further differentiated from T. folkertsae by having less elongate pedipalpal tibiae (length/width = 3.21-4.00 in T. magnexa , 4.05-4.83 in T. folkertsae ). Male T. magnexa can be further differentiated from male T. pulchra by having a larger genital field (length ♂ = 125-148 in T. magnexa , 110-123 in T. pulchra ; width ♂ = 115-125 in T. magnexa , 87-95 in T. pulchra ) and more elongate pedipalpal tibiae (length/width ♂ = 3.78-4.00 in T. magnexa , 3.00-3.35 in T. pulchra ). Female T. magnexa can be differentiated from female T. pulchra by having a wider genital field (♀ 170-188 in T. magnexa , 147-160 in T. pulchra ) and longer pedipalpal tibiae (♀ 102-113 in T. magnexa , 82-93 in T. pulchra ).

Re-description.

Female (Figure 135) (n = 6) (holotype measurements in parentheses when available) with characters of the genus with following specifications.

Dorsum - (680-750 (750) long; 500-560 (560) wide) ovoid with bluish-purple or reddish-purple coloration separated into anterior and posterior portions with red medially. Anterio-medial platelets 155-170 (162.5) long; 57.5-65 (60) wide). Anterio-lateral platelets (192.5-210 (210) long; 72.5-85 (85) wide) partially fused to dorsal plate (especially posteriorly). Dgl-4 close to the edge of the dorsum (distance between Dgl-4 390-410 (400)). Dorsal plate proportions: dorsum length/width 1.28-1.42 (1.34); dorsal width/distance between Dgl-4 1.28-1.40 (1.40); anterio-medial platelet length/width 2.42-2.72 (2.71); anterio-lateral platelet length/width 2.47-2.71 (2.47); anterio-lateral/anterio-medial length 1.13-1.33 (1.29).

Gnathosoma - Subcapitulum (330-355 long (ventral); 251-277 long (dorsal); 150-170 tall) mostly colorless. Rostrum (137.5-150 long; 47.5-52.5 wide). Chelicerae (335-363 long) with curved fangs (55-78 long). Subcapitular proportions: ventral length/height 2.00-2.37; rostrum length/width 2.75-3.00. Pedipalps with tuberculate ventral extensions on femora and genua. Palpomeres: trochanter (47.5-52.5 (50) long); femur (127.5-135 (135) long); genu (75-82.5 (80) long); tibia 102.5-107.5 (102.5) long; 26.25-30 (28.75) wide); tarsus (17.5-25 (22.5) long). Palpomere proportions: femur/genu 1.58-1.71 (1.69); tibia/femur 0.76-0.83 (0.76); tibia length/width 3.57-4.00 (3.57).

Venter - (770-900 (830) long; 588-672 (660) wide) colorless. Gnathosomal bay (165-190 (165) long; 95-125 (125) wide). Cxgl-4 subapical. Medial suture (0-15 (7.5) long) occasionally absent. Genital plates (190-207.5 (207.5) long; 170-187.5 (187.5) wide). Additional measurements: Cx-1 (299-359 (320) long (total); 96-155 (155) long (medial)); Cx-3 (369-455 (455) wide); anterior venter (167.5-175 (175) long). Ventral proportions: gnathosomal bay length/width 1.32-1.87 (1.32); anterior venter/genital field length 0.84-0.91 (0.84); anterior venter length/genital field width 0.93-1.03 (0.93); anterior venter/medial suture (proportion cannot be calculated for specimens without a medial suture) 11.33-23.33 (23.33).

Male (Figure 136) (n = 6) (allotypic measurements in parentheses when available) with characters of the genus with following specifications.

Dorsum - (540-630 (600) long; 390-450 (430) wide) ovoid with bluish-purple or reddish-purple coloration separated into anterior and posterior portions with red medially. Anterio-medial platelets (125-140 (132.5) long; 47.5-52.5 (50) wide). Anterio-lateral platelets (158.75-192.5 (170) long; 60-70 (60) wide) partially fused to dorsal plate (especially posteriorly). Dgl-4 close to the edge of the dorsum (distance between Dgl-4 310-350 (310)). Dorsal plate proportions: dorsum length/width 1.35-1.43 (1.40); dorsal width/distance between Dgl-4 1.26-1.39 (1.39); anterio-medial platelet length/width 2.48-2.95 (2.65); anterio-lateral platelet length/width 2.44-2.85 (2.83); anterio-lateral/anterio-medial length 1.22-1.43 (1.28).

Gnathosoma - Subcapitulum (272.5-300 (285) long (ventral); 200-229 (215) long (dorsal); 113-127.5 (122.5) tall) mostly colorless. Rostrum (110-122.5 (117.5) long; 40-45 (42.5) wide). Chelicerae (260-292 (290) long) with curved fangs (49-60 (55) long). Subcapitular proportions: ventral length/height 2.22-2.42 (2.33); rostrum length/width 2.59-2.84 (2.76). Pedipalps with tuberculate ventral extensions on femora and genua. Palpomeres: trochanter (37.5-45 (40) long); femur (105-112.5 (110) long); genu (65-72.5 (67.5) long); tibia (85-97.5 (90) long; 22.5-25 (22.5) wide); tarsus (17.5-20 (20) long). Palpomere proportions: femur/genu 1.55-1.67 (1.63); tibia/femur 0.80-0.87 (0.82); tibia length/width 3.78-4.00 (4.00).

Venter - (640-770 (710) long; 465-550 (550) wide) colorless. Gnathosomal bay (127.5-160 (127.5) long; 77.5-95 (77.5) wide). Cxgl-4 subapical. Medial suture (62.5-85 (75) long). Genital plates (125-147.5 (140) long; 115-125 (115) wide). Additional measurements: Cx-1 (251-285 (270) long (total); 102-140 (140) long (medial)); Cx-3 (335-375 (375) wide); anterior venter (207.5-240 (220) long). Ventral proportions: gnathosomal bay length/width 1.37-1.94 (1.65); anterior venter/genital field length 1.57-1.78 (1.57); anterior venter length/genital field width 1.80-1.98 (1.91); anterior venter/medial suture 2.82-3.68 (2.93).

Immatures unknown.

Etymology.

Habeeb (1957) did not specify an etymology for the specific epithet ( magnexa ). However, surely this name refers to the similarity of this species to the Palaearctic T. connexa (Koenike, 1908) ( néos, G. new).

Distribution.

Eastern (Figure 134).

Remarks.

Upon examining the types of T. magnexa and T. neoconnexa Habeeb, 1957, all characters for both species overlap with members of only one clade in our analyses. Furthermore, the primary character Habeeb (1955, 1957, 1961) used to differentiate T. magnexa from T. neoconnexa was body size, which is known to be a highly variable character. Therefore, it is apparent that these represent the same species hypothesis and must be synonymized. We therefore synonymize T. neoconnexa as the junior synonym of T. magnexa .

In all analyses, Torrenticola magnexa groups with other members of the Rusetria Complex with high support, all specimens were less than 1% different in COI sequence from each other, and these specimens were 11-13% different from sister species. In the combined analysis, all eastern members of Rusetria Complex are monophyletic, and T. magnexa was recovered at the base of that eastern clade. Interestingly, most of the species within the more basal lineages of this eastern clade have lateral platelets that are free from the dorsal plate; whereas western species and most eastern species have lateral platelets fused to the dorsal plate. This is interesting because T. magnexa , which have lateral platelets partially fused to the dorsal plate, is recovered in an intermediate position between western species that have fused platelets and eastern species with unfused platelets.

Based upon the partially fused posterio-lateral platelets and the distribution, we place this species within the Partial 2-Plate Identification Group.

This species hypothesis is supported by biogeography, low COI divergence within the species (0-2%) and high divergence between species (3-15%), and the morphological characters outlined in the diagnosis.