Bryobia mercantourensis, Auger & Migeon, 2014

Auger, P. & Migeon, A., 2014, Three New Species Of Tetranychidae (Acari, Prostigmata) From The French Alps (South-Eastern France), Acarologia 54 (1), pp. 15-37 : 21-27

Bryobia mercantourensis n. sp.

( Figures 4-7 )

Type-specimens — Holotype (female), 15 female 7 deutonymhs, 4 protonymphs and 7 larvae paratypes on 30 microscopic preparations from Genista cinerea (Vill.) DC. (Leguminosae) , cime de Braus (43.875°N 7.394°E, alt. 1040 m), LucØram , France, 23-VII-2009, leg. P. Auger. All the material deposited in the INRA collection of the CBGP, coll. Auger-Migeon N ° 1758 for holotype, 1759-1787 for paratypes.

Other material examined — Ten females on 8 microscopic preparations from G. cinerea, Pont du commun (43.985°N 7.547°E, alt. 450 m), Saorge , France, 21-VII-2009, leg. P. Auger, coll. Auger- Migeon N ° 1700-1707 .

Diagnosis — With four long setae present on the interior dorsal row of femur I this species belongs to the berlesei -group ( Eyndhoven, 1957; Eyndhoven and Vacante, 1985). Empodial pad of leg I with a pair of tenent hairs others with two rows of tenent hairs, inner propodosomal lobes are well separated and more or less cone-shaped with large fused base, outer lobes smaller and cone shaped, dorsal setae inserted in small tubercles, spatulate with sacral and clunal setae slightly longer.

Description:

Female: Holotype 600 µm long (excluding gnathosoma, from the tip of v 1 to the tip of h 1), width 350 µm. Ten paratypes measured, 540 – 595 µm long, width 310 – 360 µm.

Dorsum — Prodorsum with four pairs of setae and with developed anterior lobes ( Figs. 4A , 6A ). Outer propodosomal lobes rather low, conical, not extending beyond medial of inner lobes. Medial projection well expanded, inner lobes well separated in their distal part with variable obvious incision, 13 (7 – 13) µm in depth (measured from the bottom of the incision between the inner lobes). A horizontal line joining tip of v 2 setae located on the outer lobes crosses v 1 setae about their base, v 1 about two-thirds the size of v 2. Dorsal body setae spatulate, inserted on tubercles, subequal in length with the exception of v 1 setae far smaller, sacrals (f 1, f 2) and clunals (h 1) somewhat longer ( Figs. 4A, B ). Dorsocentral setae (c 1, d 1 and e 1) shorter than distances between consecutive setae (length of holotype and variations of ten paratypes): v 1 22 (18 – 21); v 2 33 (29 – 32); sc 1 32 (26 – 31); sc 2 26 (22 – 27); c 1 30 (25 – 31); c 2 30 (23 – 29); c 3 27 (22 – 28); d 1 26 (22 – 27); d 2 28 (21 – 28); d 3 26 (23 – 30); e 1 25 (21 – 27); e 2 29 (25 – 29); e 3 34 (25 – 31); f 1 37 (25 – 37); f 2 40 (29 – 41); h 1 36 (27 – 40). Distances between setae: c 1 - c 1 62 (58 – 66), d 1 - d 1 48 (47 – 52), e 1 - e 1 31 (24 – 34), c 1 - d 1 85 (81 – 97), d 1 - e 1 72 (62 – 70). Sacral setae (f 1 and f 2) in marginal position. Dorsal integument on propodosoma with irregular reticulated granulated pattern medially, folds more or less inclined laterally. Large transverse folds with fibrous appearance on hysterosoma, more or less arched in the distal part comprised between e 3 and h 1 setae. Three pairs of oval-shaped areas present between c 1 - c 2, d 1 - d 3, and e 1 - e 3 setae and a triangularly rounded one present posteriorly.

Gnathosoma — Stylophore longer than wide. Tibial claw of palpus bidentate. Palptarsus elongated, about 24 (20.5 – 25) long with three tactile setae, three eupathidia and one solenidion ( Fig. 6B ). Eupathidia ul’ ζ, ul” ζ slightly inferior to su ζ in length, solenidion shorter. Peritreme anastomosed distally in a relatively long and slender enlargement ( Fig. 6C ): length 33 (31 – 40), width 8 (6.5 – 8.5).

Venter — Striation transverse between 1 st (1a) and 2 nd (3a) pairs of setae, absent (rare irregularly folds may be present) between 2 nd and 3 rd (4a), longitudinal between members of 4a setae and transverse between 3 rd and aggenital (ag) pairs of setae. Area immediately anterior to genital flap with irregular longitudinal striation. Sacculus of spermatheca oval shaped ( Fig. 6D ). Three anal and two para-anal setae present.

Legs — Length (femur-genu-tibia-tarsus) inferior to body length, leg I 419 (390 – 410) µm long and (length of holotype and variations of ten paratypes), leg II 235 (215 – 230), leg III 240 (220 – 240), leg IV 260 (250 – 280). Length of segments of leg I as follows: femur 155 (135 – 150), genu 70 (65 – 70), tibia 100 (84 – 105), tarsus 93 (85 – 99). Leg setal count as follows ( Figs. 5A, B, C ):

I 2 - 1 - 14[13] - 8[7] - 13 + (1) - 19 + (5) + 2 duplexes; II 1 - 1 - 9[8] - 5 - 9 - 15 + (2) + 1 duplex;

III 1 - 1 - 7[6] - 7[6] - 9 - 13 + 1 duplex;

IV 1 - 1 - 5 - 6 - 9 - 14 + (1).

Internal dorsal row on femur I with four long setae (from proximal to distal setae) and one normal setae: 43 (41 – 47), 51 (47 – 53), 41 (39 – 46) and 42 (38 – 41) µm in length. Tarsus III associated setae serrate and approximate with solenidion forming duplex, the tactile member longer and proximal ( Fig. 5D ) – length of solenidion 14 (12.5 – 15), length of tactile 20 (16 – 20); tarsus IV with solenidion wellseparated from tactile, short and proximal ( Fig. 5E ) – length of solenidion 9 (8 – 9.5), distance between solenidion and tactile 6.5 (4.5 – 6.5). True claws uncinate, claw and empodium I with one pair of tenent hairs, other claws with two pairs and other empodial pads each provided with two rows of tenent hairs ( Figs. 5F, G ).

Deutonymph ( Figs. 7A, B ):

Dorsum — Prodorsal lobes developed, conical in shape, inner lobes less separated as in female, prodorsal setae v 1 and v 2 spatulate and serrate, v 2 the largest almost twice the length of v 1 setae; a horizontal line joining the tips of v 2 setae also nearly passes the tips of v 1 setae. Dorsal body setae inserted on tubercles (stronger in posterior area), spatulate excepted the third pair of dorsolateral setae (e 3), sacrals (f 1, f 2) and clunals (h 1), gradually longer, narrower and pectinate. Dorsocentral setae, c 1, d 1 and e 1, shorter than distances between consecutive setae. Lengths of dorsal setae (variations of 3 deutonymphs): v 1 15 – 17; v 2 25 – 29; sc 1 26 – 31; sc 2 21.5 – 23; c 1 22 – 25; c 2 23 – 24.5; c 3 23 – 24.5; d 1 21.5 – 22.5; d 2 20 – 22; d 3 23.5 – 24; e 1 21 – 21.5; e 2 26.5 – 30; e 3 32 – 34.5; f 1 36.5 – 40; f 2 39 – 40; h 1 35 – 38. Setae f 1 and f 2 in marginal position.

Legs — Length inferior to body length. Internal

E F

10 µm

dorsal row on femur I with two long setae and one normal seta. Leg setal count as follows:

I 2 - 1 - 8 - 4 - 9 + (1) - 14 + (1) + 2 duplexes;

II 1 - 1 - 6 [5] - 4 - 5 - 11 + 1 duplex;

III 1 - 1 - 2 - 3 - 5 - 10 + (1);

IV 1 - 0 - 2 - 3 - 5 - 10.

True claws uncinate with one pair of tenent hairs, empodia provided with two rows of tenent hairs, empodial pad of empodium I shorter.

Protonymph ( Figs. 7C, D ):

Dorsum — Prodorsal lobes weakly developed, tubercle like, v 1 very short, spatulate and serrate with spiky appearance, v 2 larger, spatulate and serrate. Other dorsal body setae spatulate with the exception of e 2 sub-spatulate and the following (e 3, f 1, f 2 and h 1) elongate, serrate and larger. Lengths of dorsal setae (variations of 4 protonymphs): v 1 7 – 11; v 2 23 – 28; sc 1 22.5 – 25.5; sc 2 18.5 – 20.5; c 1 18 – 21; c 2 17 – 18.5; c 3 16 – 18.5; d 1 16 – 18.5; d 2 20 – 23; d 3 21 – 31; e 1 18 – 22; e 2 27 – 31; e 3 33 – 36; f 1 32 – 36; f 2 34 – 37; h 1 35 – 37. Setae f 1 and f 2 in marginal position.

Legs — Length inferior to body length. Internal dorsal row on femur I with one long seta and one normal seta. Leg setal count as follows:

I 2 - 1 - 3 - 4 - 5 + (1) - 10 + (2) + 2 duplexes;

II 1 - 0 - 3 - 4 - 5 - 9 + 1 duplex;

III 1 - 0 - 2 - 2 - 5 - 8;

IV 0 - 0 - 2 - 2 - 5 - 6.

True claws uncinate with one pair of tenent hairs, empodia with two rows of tenent hairs.

Larvae ( Figs. 7E, F ):

Dorsum — Prodorsal lobes absent, v 1 very short and rod like, v 2 long, serrate, inserted on small tubercles. Dorsal body setae elongate, serrate, setae e 3 to h 1 the largest. Lengths of dorsal setae (variations of 4 larvae): v 1 5 – 7; v 2 23 – 25; sc 1 18 – 22; sc 2 18 – 20; c 1 19 – 24; c 2 17 – 19; c 3 13 – 16; d 1 19 – 24; d 2 18 – 22; d 3 24 – 29; e 1 23 – 28; e 2 25 – 31; e 3 32 – 36; f 1 35 – 39; f 2 35 – 40; h 1 35 – 37. Seta f 1 in normal position.

Legs — Length inferior to body length. Internal dorsal row on femur I with one long seta and one normal seta. Leg setal count as follows:

I 1 - 0 - 3 - 4 - 5 + (1) - 7 + 1 duplex;

II 0 - 0 - 3 - 4 - 5 - 7 + 1 duplex;

III 0 - 0 - 2 - 2 - 5 - 6.

True claws uncinate with one pair of tenent hairs, empodia with two rows of tenent hairs.

Remarks — In addition to the four long setae present on the interior dorsal row of femur I, as this species bears one pair of tenent hairs on the empodium I, B. mercantourensis is close to B. provincialis Eyndhoven and Vacante, 1985 and B. dikmenensis Eyndhoven and Vacante, 1985 that belong to the berlesei -group ( Eyndhoven, 1957; Eyndhoven and Vacante, 1985). This species is clearly smaller in length and width than B. provincialis and the first leg is also obviously longer in the latter. Conversely, B. mercantourensis is slightly longer and obviously broader than B. dikmenensis and the second, third and fourth pairs of legs are shorter in the latter. It is mainly distinctive from B. provincialis and B. dikmenensis by the shape of the propodosomal lobes: mammelliform with inner lobes largely fused in the latter whereas conical and well separated in B. mercantourensis . The latter can also be separated from B. provincialis by differences in shape of deutonymph’s dorsohysterosomal setae e 3 and f 1, subspatulate vs. elongate and narrow in B. provincialis and B. mercantourensis respectively. Legs chaetotaxy also clearly differs between the deutonymphs of these two species. Bryobia dikmenensis can be distinguished from B. mercantourensis and from B. provincialis by the reduced size of its second and third pairs of dorsocentral setae (d 1 and e 1) in comparison with other dorsohystersomal setae. Several characters found in juveniles of B. dikmenensis and of B. mercantourensis can also be used to separate them: the ratio between larval v 1 and v 2 setae is two-fold higher (4 vs. 2) in B. mercantourensis ; protonymphal prodorsal lobes in B. dikmenensis ressemble that of female whereas they are almost absent (weakly developed) in B. mercantourensis .

Etymology — The species designation mercantourensis is named after the location where the specimens were found: in the Mercantour French National Park.

Figures

FIGURE 4: Bryobia mercantourensis n. sp., female: A – dorsal aspect; B – dorsal c1 seta.

FIGURE 5: Bryobia mercantourensis n. sp., female: A – tarsus and tibia I; B – genu and femur I; C – tarsus, tibia, genu and femur II; D – duplex setae on tarsus III; E – solenidion and associated tactile seta on tarsus IV; F – empodium I; G – empodia II-IV.

FIGURE 6: Bryobia mercantourensis n. sp., female: A – variations in prodorsal lobes; B – Palpal tibia and tarsus; C – peritremal enlargement; D – spermatheca (variations between preparations).

FIGURE 7: Bryobia mercantourensis n. sp.: A – deutonymphal prodorsal lobes; B – deutonymphal dorsal hysterosomal distal part; C – protonymphal prodorsal lobes; D – protonymphal dorsal hysterosomal distal part; E – larval prodorsal anterior part; F – larval dorsal hysterosomal distal part.