Agistemus riograndensis Johann and Ferla

Johann, Liana, Carvalho, Gervásio Silva, Majolo, Fernanda & Ferla, Noeli Juarez, 2013, Stigmaeid mites (Acari: Stigmaeidae) from vineyards in the state of Rio Grande do Sul, Brazil, Zootaxa 3701 (2), pp. 238-256 : 247-250

Agistemus riograndensis Johann and Ferla sp. nov.

( Fig. 5 )

Description. FEMALE. Gnathosoma . Palp coxae with 1 spiniform setae; trochanter without setae; femur with 3 long and serrate setae, 1 of them more robust; genu with 1 long seta reaching distal claw; tibia with 2 setae, 1 claw and 1 accessory claw robust, tarsus with 4 setae, 2 solenidia and 1 trifurcated sensillum ( Fig. 5 B). Infracapitulum with 2 pairs of long setae and 2 pairs of adoral setae distally. Idiosoma . Oval outline. Dorsum: 7 smooth dorsal shields with setae inserted on small tubercles. Prodorsal shield with 3 pairs of long and serrate setae, 1 pair of eyes and 1 pair of post-ocular bodies. Hysterosomal shield with 5 pairs of long and serrate setae. Seta c1 reaching the base of d1. 4 small shields each with 1 lanceolate seta (setae c2 and f). Suranal shield with 2 pairs of setae, h1 and h2. Podocephalic canal starting between the base of palps and leg I, extendig to base of leg II. Venter: 3 pairs of slender setae between coxae, 1a at level of coxa II, 3a anterior to coxa III and 4a at level of coxa IV. Anogenital regions with horseshoe-shaped shield that surrounds genital opening ( Fig. 5 C) anteriorly, with 2 pairs of agenital setae (ag1 and ag2). Genital region with 4 pairs of setae (g1, ps3, ps2, and ps1). Seta g1 reaching base of ps3. Setae ps3, ps2 and ps1 robust and slightly serrate. Leg I – IV setation ( Fig. 5 D): coxae 2(1)-1-2-2; trochanters 1-1-1-1; femora 5-4-2-2; genua 4-1-0-0; tibiae 5(1)-5(1)-5(1)-5(1); tarsi 12(1)-9(1)-7(1)-7.

MALE. Gnathosoma . As in female. Idiosoma . Oval outline. Dorsum: 5 smooth dorsal shields and setae inserted on small tubercles. Prodorsal shield with 3 pairs of long and serrate setae, 1 pair of eyes and 1 pair of postocular bodies. Hysterosomal shield with 6 pairs of long and serrate setae, including seta f. 2 humeral shields with setae c2. Suranal shield with 2 pairs of setae, h1 and h2. Venter: 3 pairs of slender setae between coxae, 1a at level of coxa II, 3a anterior to coxa III and 4a at level of coxa IV. Terminal anogenital region with 5 pairs of setae. Leg I – IV setation: coxae 2(1)-1-2-2; trochanters 1-1-1-1; femora 5-4-2-2; genua 4-1-0-0; tibiae 5(1)- 5(1)- 5(1)- 5(1); tarsi 12(2)-9(2)-7(1)-7(1).

Measurements of this species are provided in Table 4 .

Character measured Female holotype Female (n=14) Male (n=5) Type material. CAS-03 (MCN). Female holotype from Candiota, V. vinifera, Alfrocheiro cultivar, 5 March 2007, coll. L. Johann. 4 female paratypes from Bento Gonçalves: 1 female from V. vinifera, Cabernet Sauvignon cultivar, 7 November 2006, coll. L. Johann; 1 female on same host, Chardonnay cultivar, 5 March 2007, coll. L.B.

Oliveira; 1 female on same host, Merlot cultivar, 7 November 2006, coll. T.B. Horn; 1 female on same host, Pinot Noir cultivar, 3 January 2007, coll. L. Johann; 6 female and 1 male paratypes from Boqueirão do Leão: 2 females and 1 male from V. vinifera, Cabernet Sauvignon cultivar, 24 April 2006, coll. T.B. Horn; 1 female from V. labrusca, Bordeaux cultivar, 8 January 2006, coll. T.B. Horn; 1 female with same data, 16 March 2006, coll. T.B. Horn; 2 females with same data, 30 January 2007, coll. T.B. Horn; 2 female and 1 male paratypes from Dois Lajeados: 1 female from V. labrusca, Bordeaux cultivar, 17 April 2006, coll. T.B.Horn; 1 female and 1 male from V. vinifera, Cabernet Sauvignon cultivar, 15 January 2006, coll. F.Diel; 1 female and 3 male paratypes from Encruzilhada do Sul, V. vinifera, Pinot Noir cultivar, 13 February 2007, coll. L. Johann.

Type deposition. Holotype and all paratypes in MCN.

Differential diagnosis. This species is similar to A. brasiliensis by c1 setae longer than the distance between the base of c1 and the base of d1. In Agistemus riograndensis sp. nov., setae sci, c1, d1, and d2 are 25% longer than those in A. brasiliensis ; the distance between the bases of ve setae is shorter than in A. brasiliensis ; and the ratio between ve/ve-ve is 2.8–5.8; g1 setae exceed the bases of setae ps3, but do not reach the bases of ps2. In A. brasiliensis , ve/ve-ve ratio is 1.2–3.4 and gl setae exceed the bases of ps2 setae. In addition, the measurements of Agistemus riograndensis sp. nov. are similar to those of Agistemus inflatus Meyer, 1969 . Agistemus riograndensis sp. nov. bears four setae on genu I and the bases of the dorsal setae are not inflated, whereas A. inflatus has three setae on genu I and the bases of the dorsal setae inflated.

Etymology. The species name comes from the type locality – the State of Rio Grande do Sul (“ riograndensis ”).

Remark. The new species was observed together with Panonychus ulmi (Tetranychidae) and Calepitrimerus vitis (Eriophyidae) , and it is possibly a predator of these phytophagous.

Figures

FIGURE 5. Agistemus riograndensis Johann and Ferla sp. nov. (female). A: dorsum; B: palp; C: anogenital region ventrally; D: legs I and II in dorsal view.

Tables

TABLE 4. Measurements of Agistemus riograndensis Johann & Ferla sp. nov.

	Mean	SD	Max	Min	Mean	SD	Max	Min
Body length 550	509	50.9	575	412	362	58.5	428	268
Body width 305	364	48.1	432	275	262	13.4	310	206
Idiosoma 385	280	43.3	340	193	192	43.4	205	175
ve 54 sci 86	54 86	3.5 4.9	60 92	48 77	40 58	5.4 5.7	46 64	34 50
sce 78	78	4.7	89	70	51	5.5	56	43
c 1 74 c 2 57 d 1 75 d 2 75 e 1 83 e 2 85 f 67	76 52 75 75 81 81 66	3.3 6.5 3.7 4.9 4.4 5.0 3.8	80 60 82 84 89 89 73	70 39 70 66 72 71 60	48 37 36 47 22 50 49	4.9 5.3 4.9 6.9 4.6 7.0 1.9	53 43 44 55 27 57 51	42 30 31 38 16 41 46
h1 46	41	3.7	47	32	13	1.1	15	12
h2 31	29	2.2	32	25	17	1.2	18	15
ve-ve 13	15	2.3	18	10	20	3.2	24	15
c1-c1 41	40	3.0	44	35	37	6.4	42	26
d1-d1 84	82	6.0	90	70	69	3.1	72	65
e1-e1 35 f-f 80	35 74	4.1 12.0	44 95	30 55	32 38	3.2 2.1	36 41	28 36
h1-h1 22	20	2.3	24	15	10	1.7	11	7
ve/ve-ve 4.15	3.7	0.7	5.8	2.8	2.0	0.2	2.3	1.7
c1/c1-c1 1.8	1.9	0.2	2.2	1.6	1.3	0.3	1.9	1.0
d1/d1-d1 0.89	0.9	0.1	1.0	0.8	0.5	0.1	0.6	0.5
e1/e1-e1 2.37	2.3	0.3	2.8	1.7	0.7	0.2	1.0	0.4
f/f-f 0.83	0.9	0.2	1.2	0.6	1.3	0.1	1.4	1.2
h1/h1-h1 2.09	2.0	0.2	2.5	1.7	1.4	0.3	1.9	1.1
SD = Standard Deviation.