Securiops primasia, Kaltenbach & Phlai-ngam & Suttinun & Gattolliat, 2023

Kaltenbach, Thomas, Phlai-ngam, Sirikamon, Suttinun, Chanaporn & Gattolliat, Jean-Luc, 2023, First report of the Afrotropical genus Securiops Jacobus, McCafferty & Gattolliat (Ephemeroptera, Baetidae) from Southeast Asia, with description of a new species, ZooKeys 1157, pp. 127-143 : 127

publication ID	https://dx.doi.org/10.3897/zookeys.1157.99642
publication LSID	lsid:zoobank.org:pub:872505C2-6DFC-410A-8C77-704A6B3D086B
persistent identifier	https://treatment.plazi.org/id/CD408527-25B4-4F63-BD52-32AFEECF3514
taxon LSID	lsid:zoobank.org:act:CD408527-25B4-4F63-BD52-32AFEECF3514
treatment provided by	ZooKeys by Pensoft
scientific name	Securiops primasia
status	sp. nov.

Treatment

Securiops primasia sp. nov.

Figs 1 View Figure 1 , 2 View Figure 2 , 3 View Figure 3 , 4 View Figure 4 , 5 View Figure 5 , 6 View Figure 6 , 7 View Figure 7 , 8 View Figure 8

Differential diagnosis.

Larva. The following combination of characters differentiate larvae of the new species from other species of Securiops : (1) maxillary palp segment II ca. 0.7 × as long as segment I (Fig. 3a, d View Figure 3 ); (2) maxilla ventrolaterally with two groups of simple setae (Fig. 3e View Figure 3 ); (3) femur approx. twice as long as tibia; tarsus approx. 1.4 × as long as tibia; claw approx. 0.7 × as long as tarsus (Fig. 5a View Figure 5 ); (4) hind protoptera absent; (5) tergalii on abdominal segments I-VII, each with two lamellae (Fig. 7b View Figure 7 ); (6) abdominal segments VIII and IX with large lateral spines, segment VII with minute lateral spines (Fig. 6a View Figure 6 ); and (7) paraproct with four large, pointed spines (Fig. 7a View Figure 7 ).

Description.

Larva (Figs 1 View Figure 1 - 7 View Figure 7 ). Body length 3.8-4.7 mm. Cerci approx. ½ body length, slightly longer than paracercus. Antennae somewhat longer than head length.

Colouration (Figs 1a-d View Figure 1 ). Head, thorax and abdomen dorsally brown, with pattern as in Fig. 1a View Figure 1 . Abdomen laterally light brown, with brown spots on most segments (absent or inconspicuous on segments I, IV and X), and larger additional brown spots on segments VI and VIII. Head, thorax and abdomen ventrally light brown, abdomen laterally with brown spots on segments VIII-X (Fig. 1c View Figure 1 ). Legs light brown, femur with distomedial brown spot, tibia with ventrobasal brown spot, and claw basally darker. Caudalii light brown, with brown annulation at distal margins of segments (Fig. 1a View Figure 1 ).

Labrum (Fig. 2a View Figure 2 ). Rectangular, length ca. 0.7 × maximum width. Distal margin with broad, shallow, medial emargination. Dorsal surface scattered with fine, simple setae; ventral surface with apicolateral patch of long, bifid setae near margin. Anterior margin apicolaterally with row of long, bifid setae, and medially with row of stout, medium, bifid setae.

Right mandible (Fig. 2c, d View Figure 2 ). Incisor and kinetodontium cleft to base. Incisor with three denticles; kinetodontium with three denticles. Prostheca stick-like, apicolaterally denticulate. With restricted tuft of long setae between prostheca and mola. Tuft of setae at apex of mola present.

Left mandible (Fig. 2e, f View Figure 2 ). Incisor and kinetodontium cleft to base. Incisor with three denticles; kinetodontium with four denticles. Prostheca stick-like, apicolaterally denticulate. With large tuft of long setae between prostheca and mola. Tuft of setae at apex of mola present.

Hypopharynx and superlinguae (Fig. 2b View Figure 2 ). Lingua as long as superlinguae, broad; slightly longer than broad; distal margin almost straight, with fine, simple setae, not forming a medial tuft. Superlinguae distally broadly rounded; lateral margins rounded; fine, medium to long, simple setae along distal margin.

Maxilla (Fig. 3a-e View Figure 3 ). Galea-lacinia ventrally with two simple, apical setae under canines (Fig. 3c View Figure 3 ). Canines long and very slender (Fig. 3a View Figure 3 ). Three long, slender, pectinate denti-setae (Fig. 3b View Figure 3 ). Medially with one bifid, spine-like seta (dorsolateral insertion) and two groups of simple, spine-like setae (ventrolateral insertions) (Fig. 3e View Figure 3 ). Maxillary palp 2-segmented, more than twice as long as length of galea-lacinia; palp segment II ca. 0.7 × length of segment I; setae on maxillary palp long, fine, simple, scattered over surface of segments I and II; apex of last segment pointed (Fig. 3a, d View Figure 3 ).

Labium (Fig. 4a-e View Figure 4 ). Glossa much shorter than paraglossa; outer margin with row of simple setae; inner margin distomedially serrate and with fine, simple setae; ventroapically with arc of long, simple setae. Paraglossa slightly curved inward; outer margin with row of long, simple setae; inner margin with medium row of simple setae, and submarginal row of long, simple setae, basally with dense row of long, simple setae. Labial palp 2-segmented. Segment II large, nearly trapezoidal with distal corner prolonged, pointed, curved inward; inner margin with many long, fine setae, in basal half with submarginal row of long, spine-like, setae-like processes; distal corner with dense, long, fine setae.

Hind protoptera absent.

Foreleg (Fig. 5a-k View Figure 5 ) very slender. Ratio of foreleg segments 2.0:1.0:1.4:0.7. Trochanter. Ventral margin with row of short, spine-like setae (Fig. 5g View Figure 5 ). Femur. Length ca. 6 × maximum width. Dorsal margin with row of short, spine-like setae; distally with transverse arc of long, fine setae (difficult to see) (Fig. 5i View Figure 5 ). Apex rounded. Ventral margin with row of short, spine-like setae; femoral patch absent. Tibia. Dorsal margin with row of short, spine-like setae; proximally with arc of long, fine setae near margin (difficult to see) (Fig. 5j View Figure 5 ). Ventral margin with row of short to medium, curved, spine-like setae. Patellatibial suture present in basal 1/2 area. Tarsus. Dorsal margin bare; proximally with arc of long, fine setae near margin (difficult to see) (Fig. 5k View Figure 5 ). Ventral margin with row of medium, spine-like setae. Claw without denticles; subapical setae absent (Fig. 5h View Figure 5 ).

Abdominal terga (Fig. 6a, b View Figure 6 ). Lateral margins of terga: VII with some minute spines; VIII with ca. seven small to large spines; IX with five large spines and one small spine (spine at posterolateral angle excluded from count); Posterior margins of terga: I smooth, without spines; II with strongly spaced or rudimentary, triangular spines; III-VII with spaced triangular spines, longer than wide.

Abdominal sterna (Fig. 6c View Figure 6 ). Posterior margin of sterna: I-V smooth, without spines; VI-VIII with triangular spines.

Tergalii (Fig. 7b View Figure 7 ). Present on segments I-VII; all tergalii with two lamellae, second lamella much smaller. Tracheae restricted to main trunk. Tergalius I as long as length of segment II; tergalius VII as long as length of segments VIII and half IX combined.

Paraproct (Fig. 7a View Figure 7 ). With four larger, marginal spines, and some additional, minute spines in-between. Cercotractor with minute, marginal spines, hardly to see.

Imago.

Unknown.

Eggs

(Fig. 7c, d View Figure 7 ). Barrel-shaped, surface with four longitudinal rows of wide, sub-rectangular structural elements.

Genetics.

We obtained two sequences of 658 bp from specimens of two distinct populations. The K2P distance between them is 0.5%. The closest sequences available on GenBank and Bold system all belong to various species of Cloeon which is to be expected as no specimens of Securiops were previously sequenced.

Etymology.

Combination of the first part of the Latin word “prim-us” (meaning the first), and “asia” (for the continent), to highlight the first discovery of the Afrotropical genus Securiops in Asia.

Biological aspects.

The specimens were collected at altitudes between 100 m and 300 m.

Distribution

(Fig. 8 View Figure 8 ). Thailand.

Material examined.

Type-material. Holotype. Thailand • larva; Ubon Ratchathani Province, Khong Chiam District, Mekong River ; 15°19'29"N, 105°30'07"E; 156 m; 21.v.2017; leg. S. Benjamas; on slide; GBIFCH00592671; KKU-AIC GoogleMaps . Paratypes. Thailand • 3 larvae; Ubon Ratchathani Province, Khong Chiam District, Mekong River ; 15°19'29"N, 105°30'07"E; 156 m; 21.v.2019; leg. S. Benjamas; 2 in alcohol; GBIFCH00975670; KKU-AIC; 1 on slide; GBIFCH00592672; MZL GoogleMaps • 2 larvae; Ubon Ratchathani Province, Khong Chiam District, Mekong River ; 15°19'29"N, 105°30'07"E; 156 m; 18.v.2017; leg. S. Benjamas; 2 on slides; GBIFCH00592670; MZL; GBIFCH00592669; KKU-AIC GoogleMaps • 2 larvae; Ubon Ratchathani Province, Khong Chiam District, Mekong River ; 15°19'29"N, 105°30'07"E; 156 m; 18.v.2017; leg. S. Benjamas; KKU-AIC GoogleMaps .

Other material.

Thailand • larva; Kanchanaburi Province, Klong Ta Phoen; 14°06'54"N, 99°23'50"E; 31 m; 09.xi.2018; leg. C. Suttinun; in alcohol; GenBank OQ573687 View Materials ; GBIFCH00763772; KKU-AIC • larva; Tak Province, Huai Pu Ter; 16°37'51" N’, 98°37'44"E; 239 m; 27.xii.2017; leg. C. Suttinun; in alcohol; GenBank OQ573688 View Materials ; GBIFCH00763771; MZL • 3 larvae; Ratchaburi Province, Suan Phueng District, Pha Wo Thai ; 13°30'56.1"N, 99°20'39.3"E; 118 m; 20.xi.2022; leg. C. Auychida; in alcohol; VMCMU • 2 larvae; Ratchaburi Province, Suan Phueng District , Kang Som Meow ; 13°24'37.2"N, 99°16'37"E; 207 m; 20.xi.2022; leg. C. Auychida; in alcohol; VMCMU • 2 larvae; Ratchaburi Province, Suan Phueng District , Ton Nam Pha Chi ; 13°20'11.2"N, 99°14'24.8"E; 265 m; 20.xi.2022; leg. C. Auychida; in alcohol; VMCMU GoogleMaps .