Orasema longinoi, Heraty & Baker, 2020

Heraty, John M. & Baker, Austin J., 2020, New species of Orasema (Hymenoptera: Eucharitidae) from Central and South America, Journal of Natural History 54 (9), pp. 735-754 : 751-754

Orasema longinoi sp. nov. (unplaced to species group)

( Figures 2 , 5a – d )

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Diagnosis

Within Orasema , recognised by the combination of the labrum 4-digitate, antennal flagellum with 8 (♀) or 9 (♂) funiculars ( Figure 2 ), facial sculpture nearly smooth, mesoscutum and mesoscutellum scabrous to strongly rugose-areolate, specular area pilose with sparse basal setation, fore wing slightly infuscate, and hind wing densely pilose. Females all have the legs beyond the coxa entirely yellow, whereas males have most of the femora and usually all of the hind tibia brown. Molecular analyses consistently place this as a unique lineage that is close to a combination of the festiva, stramineipes and susanae species groups ( Baker et al. 2020). The festiva group all have more than 8 – 11 labral digits, whereas both the straminiepes and susanae groups have 4 or rarely up to 6 labral digits. Only the susanae group has 9 funiculars in males. Based on the variable molecular support, never being placed within any of our recognised species groups, and the unique morphology of the species, we consider this as unplaced within Orasema , but related to the groups just mentioned.

Key.

In the Burks et al. (2018) species group key, this species keys to ‘ 1 currently undescribed Neotropical species ’ in couplet 6 along with the susanae group. Orasema longinoi is more strongly scuptured on the mesosoma versus evenly and finely reticulate in the susanae group.

Female. Length 3.02 – 3.75 mm.

Colour: Head dark blue, mesosoma dark blue with violaceous reflections. Scape yellow; pedicel and anellus brown; flagellum brown. Mandible yellow with brown ventral margins; maxilla and labium light brown. Coxae dark brown with violaceous iridescence; legs beyond coxa yellow. Fore wing slightly infuscate, may be darker along impressions of cubital and basal folds; venation brown. Petiole same as mesosoma; gaster dark brown with violaceous iridescence.

Head in frontal view subtriangular; head width 1.1 – 1.8× height; upper frons weakly reticulate, lower face smooth or at most with weak surface sculpture; scrobal depression with vague parallel channels, with transverse carinae and vertical median ridge; eyes bare; inter-ocular distance 1.5 – 1.6× eye height; malar space 0.7× eye height; supraclypeal area longer than broad, smooth; clypeus smooth and pilose; epistomal sulcus narrow but shallow; anterior tentorial pit strongly impressed; anteclypeus weakly differentiated, clypeal margin very slightly rounded. Labrum with 4 digits ( Figure 5c ). Mandibular formula 3:2. Palpal formula 3:2. Occiput aciculate, shallowly emarginate in dorsal view, dorsal margin abrupt; temples present, rounded. Scape not reaching median ocellus. Pedicel subconical, as broad as F1. Flagellum with 8 funiculars; flagellum length 1.4 – 1.6× head height; anellus disc-shaped; F2 1.6 – 2.5× as long as broad, 1.2 – 1.3× as long as F3; following funiculars subequal in length, equal in width; clava subcylindrical.

Mesosoma length 1.2 – 1.4× height. Mesoscutal midlobe scabrous dorsally, sparsely setose; lateral lobe coarsely rugose-areolate; notauli deep. Axilla rugose-areolate to scabrous, dorsally well above scutellum; scutoscutellar sulcus broad, irregularly foveate, broadly separated from transscutal articulation medially; scutellar disc as long as broad, coarsely rugose-areolate with broad median depression; frenal line irregularly foveate; frenum rugose-areolate; axillular sulcus distinct and foveate; axillula reticulate. Propodeal disc broadly rounded, rugose-areolate, without depression or carina; callus rugulose, with several long hairs. Prepectus rugose-areolate. Mesepisternum rugose-areolate laterally, smooth ventrally, straight anterior to mid coxa; postpectal carina prominent. Upper mesepimeron smooth; lower mesepimeron smooth with vague sculpture; transepimeral sulcus distinct. Metepisternum laterally rugose. Propleuron convex, coriaceous. Hind coxa 2.0 – 2.4× as long as broad, reticulate dorsally, becoming smooth ventrally; hind femur 7.0 – 7.2× as long as broad, apical half with scattered short setae; hind tibia densely setose. Fore wing 2.5 – 2.7× as long as broad, 2.1 – 2.6× as long as mesothorax; basal cell sparsely pilose, costal cell, specular area and wing disc densely setose, anterior distal region of basal cell setose, and cubital vein setose; marginal fringe relatively long; submarginal vein with several long setae in basal half, with smaller setae apically; marginal vein pilose; stigmal vein 1.5 – 2.0× as long as broad, slightly angled; uncus present and blunt; postmarginal vein 4.3 – 5.0× as long as stigmal vein. Hind wing including costal cell entirely pilose.

Metasoma: Petiole cylindrical, linear in profile, 3.4 – 4× as long as broad, 1.4 – 1.5× as long as hind coxa, rugose, anterior carina strong, lateral margin rounded, ventral sulcus absent. Antecostal sulcus smooth; acrosternite posteriorly rounded. Apical setae of hypopygium present, minute. Ovipositor not exposed.

Male. Length 2.58 – 3.21 mm. Pedicel, anellus and apical half to two-thirds of hind femur dark brown; hind tibia dark brown or yellow; fore wing slightly infuscate and venation dark brown to black. Head width 1.1 – 1.3× head height; frons and lower face excluding clypeal region more strongly sculptured with rugose patterns and fine reticulate surface sculpture; flagellum length 1.5 – 2.2× head height, with 9 funiculars, F2 1.6 – 2.5× as long as broad; petiole 6.5 – 9.3× as long as broad, 2.2 – 2.8× as long as hind coxa.

Ant Host: Related species collected in nest of Pheidole dossena Wilson (Myrmicinae) (see discussion below).

Variation: There is little variation in the type material other than the wing venation being slightly lighter in colour for the female from Guanacaste ( UCRC00312148 ). Notably, the fore wings have the specular area entirely pilose. Males in the type series differ only in the colouration of the hind tibia, with one of the two males from the same locality (INBIOCRI01793753) having a yellowish-brown instead of dark brown hind tibia. Two male specimens were excluded and likely represent a different species that is recognised primarily by having a bare speculum and a proportionally longer antennal flagellum that is 1.9 – 2.0× as long as head height. The specimen from Costa Rica with the Pheidole host record has a slightly thicker, black antennal flagellum, the head and mesosoma more strongly sculptured, speculum bare, fore wing hyaline, and hind tibia yellow. The right antenna is still encased by the pupal exuvium. The Florida specimen is very similar but has a pale brown antennal flagellum. The Florida record seems odd as it would represent a very disjunct distribution, but there was a practising entomologist named Carl Stegmaier that lived in what is now Miami , so the record cannot be discounted.

DNA Matrix Name ( Baker et al. 2020): Orasema _ ” AECRI4 ” _CRI_AE_D4202.

Phylogenetic Position ( Baker et al. 2020): This species has variable placement in different analyses: as sister group to the festiva and straminiepes groups in the Anchored Hybrid Enrichment results (348 loci; susanae group and O. longinoi not included); as sister to a clade that includes the festiva, straminiepes, and susanae groups, and O. longinoi , in the Sanger Sequencing results and also in the combined Sanger and AHE results. In all results, it arises as a unique branch and is never included in any of the other species groups. This species also stands in isolation, in that we have not discovered any other morphologically similar species.

Holotype: Costa Rica: Guanacaste: Guanacaste N.P., Pitilla Biological Station, 10° 59 ʹ 31”N, 85°28 ʹ 20”W, 1.ii.1995, L. Masner, screen sweep, CR-02 [1♀, UCRCENT00312148 ], deposited in CNC . Paratypes: Costa Rica: Guanacaste: Est. Pitilla , 9 km S Santa Cecilia, P.N. Guanacaste, 700 m, 10°59 ʹ 28 ” N, 85°25 ʹ 39 ” W, 21.iii-7.iv.1993, P. Rios [2♂, INBIO: INBIOCRI01386293 , INBIOCRI01386493 ] . Est. Pitilla , 9 km S Santa Cecilia, P.N. Guanacaste, 700 m, 10°59 ʹ 28 ” N, 85°25 ʹ 39 ” W, iii.1995, P. Rios, #4359 [2♂, INBIO: INBIOCRI02242094 , INBIOCRI02242096 ] . Est. Pitilla , 9 km S Santa Cecilia, P.N. Guanacaste, 700 m, 10°59 ʹ 28 ” N, 85°25 ʹ 39 ” W, iv.1994, P. Rios, #2844 [2♂, INBIO: INBIOCRI01793740 , INBIOCRI01793753 ] .

Puntarenas: Las Cruces Biological Station , Wales Trail, 1145 m, 8°47 ʹ 21.5 ” N, 82°57 ʹ 43.1 ” W, 24 – 27.ix.2014, C. Weirauch, S. Leon, A. Knyshov, malaise trap, CR14 L3 MT2 [1♀, UCRC: UCRCENT00491415 ; D4202] . Rancho Quemado, Peninsula de Osa , 200 m, 8°40 ʹ 39 ” N, 83° 33 ʹ 53 ” W, 12.iii-3.iv.1994, A. Marin, #2796 [1♀, INBIO: INBIOCRI01759946 ] .

Related Material. Costa Rica: Heredia: 3 km S Pto. Viejo, 50 m, 10°26 ʹ 00 ” N, 84° 00 ʹ 00 ” W, 15 – 21.vii.1986, J. Longino, wet forest, in Pheidole dossena nest, #1428 [1♂, UCRC: UCRCENT00312201 ] . USA: FL: Miami-Dade, Miami , 1 m, 25°45 ʹ 42”N, 80°11 ʹ 30”W, 29.v.1961, Stegmaier [1♂, TAMU: UCRCENT00184060 ] .

Figures

Figure 2. Antennae. an, anellus; Fu8, funicular 8. Scale bar = 0.25 mm.

Figure 5. (a–c) Orasema longinoi sp. nov. ♀ holotype: (a) habitus; (b) head and mesosoma; (c) face. (d) O. longinoi ♂: habitus.