Modisimus simoni Huber, 1997

Huber, Bernhard A. & Villarreal, Osvaldo, 2020, On Venezuelan pholcid spiders (Araneae, Pholcidae), European Journal of Taxonomy 718, pp. 1-317 : 204-207

Modisimus simoni Huber, 1997

Figs 719–720 , 725–729 , 736–738 , 1058

Modisimus simoni Huber, 1997b: 235 , figs 5–7 (♂).

Hedypsillus [sic] minimus González-Sponga, 2009: 10 , figs 5a–i (1–9). New synonymy.

Misidentification

Hedypsilus simoni – González-Sponga 2010: 12 (see Modisimus culicinus above).

Notes

The species was originally described from a single poorly preserved male from a poorly specified type locality (“Orinoco”) that Eugène Simon had erroneously identified as Hedypsilus (= Modisimus ) culicinus and that he had joined with the holotype of M. culicinus in a single vial. Part of the newly collected material below is from Ciudad Guayana, close to Ciudad Bolívar, which, given its historical importance, may well have been the collecting site of the type specimen in the late 19 th century. Collecting date and collector of the holotype are unknown (the material was not collected by E. Simon as erroneously stated in Huber 1997b).

The newly collected specimens were compared with the male holotype and with the types of Modisimus minimus . All relevant structures (male palp, male chelicerae, epigynum) were found to be identical.

Diagnosis

Males differ from similar tiny congeners [ M. culicinus (Simon, 1893) ; M. chiapa Gertsch, 1977 ; M. cienaga Huber & Fischer, 2010 ; M. david Huber, 1997 ] by dorsal process of procursus ( Figs 726– 728 ); from M. culicinus also by absence of cuticular lobe frontally on ocular area (cf. Huber 1997a: fig. 1); from M. cienaga and M. david also by pair of apophyses frontally on chelicerae ( Huber 1997b: fig. 7; chelicerae unmodified in M. cienaga and M. david ). Male of M. tzotzile Brignoli, 1973 unknown. Females differ from M. david and M. tzotzile (and probably also from M. chiapa ) by presence of three pairs of marks on carapace ( Fig. 720 ); from M. cienaga by shape of internal valve ( Fig. 729 ; apparently very different in M. cienaga , but this might be an artifact, Huber et al. 2010: fig. 184); from M. culicinus by medially fused pore plates ( Figs 729 , 738 ; cf. Huber 1998a: fig. 7f).

Type material

M. simoni : ♂ holotype, MNHN (10529), Venezuela , “Orinoco”, E. Simon collection number 9629, date and collector unknown, examined.

M. minimus : ♂ holotype and 1 ♀ paratype, MIZA 105575 ( MAGS 1405), Venezuela , Portuguesa, “Acarigua (Pozo Blanco)” [approximately 9.533° N, 69.176° W], 7 Jul. 1995 (A. R. Delgado, M.A. González S.), examined.

New records

VENEZUELA – Bolívar • 6 ♂♂, 8 ♀♀, 1 juv., ZFMK (Ar 22058), and 7 ♀♀ in pure ethanol, ZFMK (Ven18-175), Ciudad Guayana , Parque La Llovizna (8.3111° N, 62.6755° W), 40 m a.s.l., 14 Nov. 2018 (B.A. Huber, O. Villarreal M.) • 1 ♂, 1 ♀, ZFMK (Ar 22059), and 2 ♀♀ in pure ethanol, ZFMK (Ven18- 165), same locality at 8.3130° N, 62.6724° W, 50 m a.s.l., 11 Nov. 2018 (B.A. Huber, O. Villarreal M.). – Mérida • 1 ♂, 4 ♀♀, ZFMK (Ar 22060), and 6 ♀♀ in pure ethanol, ZFMK (Ven20-114), near Las González (8.5066° N, 71.3183° W), 780 m a.s.l., leaf litter in dry forest near small stream, 9 Feb. 2020 (B.A. Huber, O. Villarreal M., Q. Arias C.). – Trujillo • 2 ♂♂, 2 ♀♀, ZFMK (Ar 22061), and 3 ♀♀, 1 juv. in pure ethanol, ZFMK (Ven20-138), near El Encanto (9.7599° N, 70.7329° W), 250 m a.s.l., forest near stream, 13 Feb. 2020 (B.A. Huber, O. Villarreal M., Q. Arias C.) .

Redescription

Male (Ciudad Guayana, ZFMK, Ar 22058)

MEASUREMENTS. Total body length 1.1, carapace width 0.53. Distance PME–PME 50 µm; diameter PME 60 µm; distance PME–ALE 60 µm; AME absent. Leg 1: 5.35 (1.55 +0.20 +1.40 +1.75 + 0.45), tibia 2: 1.10, tibia 3: 0.75, tibia 4: 1.25; tibia 1 L/d: 28; all femora approximately same width.

COLOR (in ethanol). Carapace pale ochre-grey, with three pairs of dark marks and dark V-mark on posterior border of ocular area; clypeus also darkened; sternum whitish; legs monochromous ochre-yellow; abdomen pale greenish-gray, with darker internal marks dorsally and white mark above spinnerets.

BODY. Habitus as in Fig. 719 . Ocular area distinctly raised. Carapace with distinct thoracic groove. Clypeus unmodified. Sternum wider than long (0.36/0.26), unmodified. Abdomen globular.

CHELICERAE. With pair of small frontal apophyses ( Huber 1997b: fig. 7).

PALPS. As in Figs 725–726 ; coxa with small retrolateral apophysis, trochanter barely modified, femur proximally with retrolateral process, distally with strong ventral apophysis; procursus ( Figs 727–728 ) with distinctive dorsal spine, prolateral-distal pointed sclerite, and complex membranous elements; genital bulb with prominent curved apophysis and dorsal membranous protrusion.

LEGS. Without spines and curved hairs; with vertical hairs in high density on all femora; retrolateral trichobothrium of tibia 1 at 22%; prolateral trichobothrium absent on tibia 1; tarsus 1 with ~8 pseudosegments, fairly distinct.

Male (variation)

Tibia 1 in ten newly collected males: 1.20–1.40 (mean 1.31). Male holotype of M. minimus , total body length: 1.1 ( not 1.93 as in original description), tibia 1: 1.50, tibia 4: 1.35 ( not 1.72 as in original description). Several drawings of the M. minimus holotype in González-Sponga (2009) are wrong: the male ocular area is wider (PLE more lateral), the posterior border of the sternum is not concave (but straight), and the male chelicerae do not have two pairs of processes (but only one).

Female

In general similar to male ( Fig. 720 ) but femora without (or very few) vertical hairs and legs with indistinct darker rings on femora (subdistally) and tibiae (proximally and subdistally). Tibia 1 in 15 newly collected females: 0.85–1.05 (mean 0.92). Epigynum ( Fig. 736 ) simple trapezoidal plate, internal bluish ‘valve’ variably visible in uncleared specimens. Internal genitalia ( Figs 729 , 737–738 ) with medially fused pore plates and prominent frontal ‘valve’ with median receptacle. Female paratype of M. minimus , tibia 1: 1.05, metatarsus 1: 1.25 ( not 0.98 as in original description).

Distribution

Apparently widespread in Venezuela , recorded from the states Bolívar, Portuguesa, Trujillo, and Mérida (Fig. 1058). The map in Fig. 1058 gives Ciudad Bolívar as type locality, but this is speculative (see Notes above).

Natural history

At Ciudad Guayana, the newly collected specimens were mostly found in relatively dry leaf litter (a thick layer of palm leaves and dicot leaves) in a strongly altered area of the Park. Few specimens were collected from pieces of bark on the ground in a more natural forested area of the Park, together with Blancoa piacoa Huber, 2000 . Near Las González, the spiders were abundant in dry leaf litter in a forest fragment near a small stream at the base of an arid hill; the species did not seem to occur under rocks higher up the hill. Near El Encanto the spiders were collected under rocks in a forest; they ran rapidly as soon as the rock was moved. Some females had a large, whitish genital plug. Three egg sacs contained ~5– 8 eggs each.

Figures

Figs 717–724. Modisimus Simon, 1893; live specimens. 717–718. M. culicinus (Simon, 1893); male and female with egg sac from La Guaira, Catia La Mar. 719–720. M. simoni Huber, 1997; male and female with egg sac from Bolívar, Ciudad Guayana. 721–724. M. repens Huber sp. nov.; male and females from Falcón, Cerro Santa Ana.

Figs 725–729. Modisimus simoni Huber, 1997; from Bolívar, Ciudad Guayana (ZFMK Ar 22058). 725– 726. Left male pedipalp, prolateral and retrolateral views. 727–728. Left palpal tarsus and procursus, prolateral (slightly dorsal) and retrolateral views. 729. Cleared female genitalia, dorsal view. Scale lines: 725–726 = 0.2 mm; 727–729 =0.1 mm.

Figs 736–741. Modisimus Simon, 1893; epigyna, ventral views and cleared female genitalia, ventral and dorsal views. 736–738. M. simoni Huber, 1997; from Bolívar, Ciudad Guayana (ZFMK Ar 22058). 739–741. M. repens Huber sp. nov.; from Falcón, Cerro Santa Ana (type locality; ZFMK Ar 22063).