Arkaditilla frim, Okayasu, 2021

Okayasu, Juriya, 2021, A new velvet ant genus Arkaditilla (Hymenoptera, Mutillidae, Trogaspidiini) from the Oriental Region, with review of species, Journal of Hymenoptera Research 84, pp. 145-168 : 145

publication ID	https://dx.doi.org/10.3897/jhr.84.68709
publication LSID	lsid:zoobank.org:pub:5F83EC63-7C79-47FD-BD29-E7A2B9328518
persistent identifier	https://treatment.plazi.org/id/E5FFF6B3-52AC-49E9-8B78-B07E69973CFF
taxon LSID	lsid:zoobank.org:act:E5FFF6B3-52AC-49E9-8B78-B07E69973CFF
treatment provided by	Journal of Hymenoptera Research by Pensoft
scientific name	Arkaditilla frim
status	sp. nov.

Treatment

Arkaditilla frim sp. nov.

Figures 5 View Figures 1–6 , 6 View Figures 1–6 , 15 View Figures 13–18 , 21 View Figures 19–36 , 29 View Figures 19–36 , 30 View Figures 19–36 , 41 View Figures 37–48 , 42 View Figures 37–48 , 55-57 View Figures 49–66 , 69 View Figures 67–72 , 75 View Figure 73–76

Diagnosis.

Male. Clypeus dorsally elevated, sloping ventrally. Mandible with weak subapical and subbasal teeth (Fig. 15 View Figures 13–18 ), ventrally deeply excised with large basal tooth (Fig. 21 View Figures 19–36 ). Scape ventral carinae divergent apically (Fig. 29 View Figures 19–36 ), densely punctate between them; F1 apical 1/3, F2, F3 basal half whitish yellow on ventral half, F5-F11 with ventral yellow to reddish brown patch; F1 strongly depressed, F1 height ~0.8 × pedicel diameter (Fig. 30 View Figures 19–36 ). T3 orange (Fig. 6 View Figures 1–6 ); cuspis weakly widened on posterior 1/3 with rounded apex (Figs 55 View Figures 49–66 , 69 View Figures 67–72 ); digitus posteriorly expanded, forming triangular projection (Fig. 41 View Figures 37–48 ); paracuspis slightly tuberculate (Fig. 69 View Figures 67–72 ); penis valve weakly expanded ventrally (Figs 56 View Figures 49–66 , 57 View Figures 49–66 ). Female. Unknown.

Description.

Male. Body length: 11.2-15.0 mm (holotype: 15.0 mm; mean: 13.1 mm); forewing length: 8.09-10.7 mm (holotype: 10.7 mm; mean: 9.37 mm).

Color and setae. Frons, vertex, gena, clypeus, pedicel, flagellum mostly, prementum, stipes, mesosoma, T4-T7, S4-S8 black; mandible brown to black, with apex always black and medial 1/5-1/2 yellowish brown; labrum, protibial spur yellow; scape, tegula brownish black; F1 apical 1/3, F2, F3 basal half whitish yellow on ventral half; F5-F11 yellow to reddish brown ventrally; trochanters brown to dark brown; coxae, femora, tibiae, tarsi dark brown to brownish black; meso- and metatibial spurs pale yellow; T1-T3, S1-S3 orange; wings pale brown on proximal 1/3, brown on distal 2/3, with veins dark brown. Upper frons, vertex, trochanters, T1, S1 with sparse long erect pale golden setae; lower frons, dorsal propodeal face, dorsal half of lateral propodeal face with dense short appressed and sparse long erect pale golden setae; eye dorsal margin with long erect black setae; gena, pronotal dorsum, metascutellum with sparse short recumbent and sparse long erect pale golden setae; clypeus with dense long recumbent pale golden setae; mandible, tibiae, tarsi, T2-T5 with sparse long recumbent pale golden setae; scape, femora, S2 with sparse long recumbent and sparse long erect pale golden setae; pedicel, F1, tegula anterior portion with sparse short recumbent pale golden setae; F2-F11 with sparse erect pale golden microsetae; pronotal collar anteriorly, T2 disc, T3-T5 medially, S3-S6 with sparse short erect pale golden setae; pronotal collar posteriorly glabrous; pronotal lateral face meso- and metacoxae with sparse long appressed pale golden setae; propleuron with sparse long appressed and sparse long erect pale golden setae; mesoscutum with sparse short recumbent black and sparse short erect pale golden to black setae; tegula inner margin with sparse short recumbent pale golden and sparse short erect pale golden to black setae; mesoscutellum with sparse short recumbent pale golden, sparse long erect black, sparse long erect pale golden setae; anterior and posterior parts of mesopleuron, metapleuron, ventral half of lateral propodeal face with sparse short appressed pale golden setae; axilla, metanotal trough, medial and ventral parts of mesopleuron, procoxa with dense long appressed and sparse long erect pale golden setae; T6-T7, S7-S8 with sparse long recumbent and sparse long erect black setae; T2 with lateral golden felt line; T1-T5, S2-S5 with posterior fringe of sparse pale golden setae; S6-S8 with posterior fringe of sparse black setae.

Structure. Head 1.82-2.00 × as wide as long (holotype: 2.00); lateral margins strongly convergent behind eye; vertex rounded posteriorly; POD/OOD = 0.56-0.58 (holotype: 0.56); OD:MOD:LOD = 1.00:1.08-1.12:0.94-1.00 (holotype: 1.00:1.12:0.94); ocellar region slightly convex, ocelli without posterior carina; antennal scrobe with weak inverted V-shaped dorsal carina not reaching inner eye margin; genal carina absent; postgenal bridge flattened; hypostomal carina weakly developed; clypeus dorsally elevated, sloping ventrally, with subventral transverse groove laterally not defined by carina; anterior clypeal margin projecting medially; mandible robust, narrowed to apex with inner margin expanded forming small subbasal tooth; mandible apex bidentate; mandible ventral margin excised into large basal tooth; mandible dorsal carina sharp; prementum flattened; scape curved medially, with two longitudinal ventral carinae divergent apically; F1 depressed, F1 height 0.67-0.80 × pedicel diameter (holotype: 0.67); relative length of pedicel, F1 and F2 = 1.00:2.85-3.06:1.92-2.29 (holotype: 1.00:3.06:2.29); F2-F11 almost equal in width; F11 as long as F2, conical.

Mesosoma widest at mesonotum including tegulae; head width:humeral width:pronotal width:mesonotal width = 88:62:91:100; humeral angle rounded, with sharp humeral carina on ventral half; mesoscutum strongly convex; mesoscutal width 1.12 × its length; tegula short rounded, posteriorly reaching mesoscuto-scutellar articulation, 1.44-1.53 × as long as wide (holotype: 1.53); notaulus evenly wide, reaching anterior 1/2 of mesoscutum, subparallel; parapsidal line length 0.25 × mesoscutal length; parascutal carina forming rounded, weakly elevated process on postero-lateral angle of mesoscutum; mesoscutellum convex without medial carina, tubercle or impunctate line; mesopleuron divided into dorsal and ventral convexities by distinct transverse mesopleural groove, ventrally without transverse precoxal ridge, longitudinal impunctate line, or precoxal swelling; dorsal propodeal face without distinct dorsum and sublateral carina, with anterior inverted triangular cell and semicircular sublateral cell; lateral margins of propodeum gradually convergent posteriorly; dorsal and lateral propodeal faces not separated by carina.

Wings well developed; distance between origin of RS on vein SC and base of stigmatic cell equal to stigmatic cell length and first abscissa of RS length; cell 2RS present.

Meso- and metacoxae evenly convex; metacoxa with weak complete inner longitudinal carina; protibial spur slender; tibiae without outer spines.

T1 without distinct dorsum; T1 spiracle weakly tuberculate; T2 evenly convex, 1.28 × as wide as long; S1 with straight medial longitudinal carina with its ventral margin slightly elevated posteriorly; S2 swollen anteriorly; T7 medially with longitudinal impunctate convex line, posteriorly not forming tubercle; S6-S8 without lateral carina or tubercle; S7 entirely exposed, 0.75 × as long as S8; S8 mostly sclerotized with posterior membranous area evenly convex posteriorly. Paramere down-curved posteriorly, with weak inner protuberance on posterior 1/2 of dorso-inner margin; inner margin of paramere dorsally with short erect golden setae; ventral lobe posteriorly projecting, pointed; parapenial lobe large, with posterior margin slightly concave; cuspis long slender, weakly widened on posterior 1/3 with rounded apex, slightly surpassing apex of penis valve, with dense long erect setae ventrally and posteriorly; digitus straight, posteriorly expanded, forming triangular projection, with dense erect golden setae posteriorly; paracuspis slightly tuberculate with few erect golden setae; penis valves symmetrical slender, weakly expanded ventrally, with posterior ventral hook, without setae.

Frons, vertex, gena, pronotal dorsum, mesoscutum, medial part of mesopleuron with large dense punctures; postgenal bridge, clypeus lateral portion, mandible outer face, scape between ventral carinae, flagellum, pronotal lateral face, propleuron, axilla, metanotal trough, anterior and posterior parts of mesopleuron, metapleuron, ventral half of lateral propodeal face, procoxa, tarsi with minute dense punctures; clypeus medial convexity with large sparse punctures; mandible mostly, pronotal collar posteriorly smooth; scape mostly, trochanters, femora, tibiae, T1 medially, T2 disc, T3-T6, S1-S2 with small sparse punctures; pedicel, pronotal collar anteriorly, meso- and metacoxa with minute sparse punctures; mesoscutellum with large confluent punctures; metascutellum with small confluent punctures; dorsal propodeal face, dorsal half of lateral propodeal face reticulate; T1-T2 laterally, T7, S3-S8 with small dense punctures; tegula mostly microreticulate with few small punctures anteriorly, postero-inner portion with minute sparse punctures.

Type material.

2♂. Holotype ♂: Malaysia: Negeri Sembilan: Pasoh Forest Reserve, 3-10.XII.1993, K. Maeto leg., coarse Malaise trap, plot 6 [FRIM]. Paratype: Malaysia: Negeri Sembilan: Pasoh Forest Reserve, 25.III-2.IV.1993, K. Konishi & K. Maeto leg., fine Malaise trap, plot 2 [1♂ NARO].

Distribution.

Malaysia: Negeri Sembilan.

Etymology.

This new species is named after FRIM, Forest Research Institute Malaysia, which was the Malaysian counterpart of the Japan-Malaysia joint research project in 1993 funded by the Ministry of the Environment of Japan. Treat as a noun in apposition.

Remarks.

This species occurs sympatrically with A. depressicornis , but this new species differs from it by having the mandible with weakly developed subbasal and subapical teeth (subbasal and subapical teeth large in A. depressicornis ), the digitus posteriorly expanded (digitus slender in A. depressicornis ), and the paracuspis tuberculate (paracuspis absent in A. depressicornis ).