Orfflellium enigmaticum Johnson, Masner & Musetti, 2009

Johnson, Norman F., Masner, Lubomír & Musetti, Luciana, 2009, Orwellium, a new Valdivian genus of Platygastridae (Hymenoptera), ZooKeys 20, pp. 21-30 : 24-27

Orfflellium enigmaticum Johnson, Masner & Musetti , gen.n., sp. n.

urn:lsid:zoobank.org:act:001233E8-5447-40C3-9F1E-0F6F19BFC044

urn:lsid:zoobank.org:act:77F632EF-5DB9-43C2-A695-5D0D9A564FD0

urn:lsid:biosci.ohio-state.edu:osuc_concepts:238175

urn:lsid:biosci.ohio-state.edu:osuc_concepts:245120

Figures 1–6 ; Morphbank 3

Description. Body length: 1.28–1.51 mm (n=20). Head color, female: brown to dark brown. Head color, male: brown to dark brown. Mesosoma color, female: brown to dark brown. Mesosoma color, male: brown to dark brown. Metasoma color, female: brown to dark brown. Metasoma color, male: brown to dark brown. Body shape: small, compact.

Head: Head shape, dorsal view: transverse. Hyperoccipital carina: absent. Occipital carina, extent: complete medially. Occipital carina, sculpture: simple. Position of lateral ocellus: remote from inner orbit, OOL> 2 ocellar diameters. Length of LOL: less than POL, less than OOL. Eye setae: glabrous. Frontal scrobe: frons convex, frontal scrobe not developed. Course of inner orbits: nearly parallel, diverging only at ventral extreme. Central keel: absent. Submedian carina: absent. Orbital carina: absent. Fan of striae arising from anterior mandibular articulation: absent. Clypeus structure: divided transversely to form anteclypeus, postclypeus. Clypeus shape: unknown. Anteclypeus shape: large, semicircular, concave. Postclypeus shape: short, strongly transverse. Apical margin of clypeus: straight. Lateral corners of clypeus: not produced, confluent with oral margin. Malar sulcus: present, fine, deeply incised, J-shaped. Genal carina: absent. Mandibular tooth orientation: transverse. Mandibular dentition: identate. Number of maxillary palpomeres: 2. Shape of penultimate maxillary palpomere: cylindrical. Number of labial palpomeres: 1. Number of antennomeres, female: 10. Number of antennomeres, male: 11. Insertion of radicle: parallel to long axis of A1. Dorsal surface A2, female: rounded. Length of A3, female: distinctly greater than length of A2. Claval formula: A7-A10/2-2-2-1. Number of clavomeres, shape criterion: Number of clavomeres, MGS criterion: 4. Number of MGS on basal clavomere: 2. Orientation of MGS: longitudinal. 5. Tyloid-bearing antennomeres, male: A5 only.

Mesosoma: Transverse pronotal carina: absent. Mesosoma length: subequal to height, mesosoma normally proportioned. Mesosoma height: greater than width. Dorsal margin of mesosoma , lateral view: convex. Vertical epomial carina: absent. Horizontal epomial carina: absent. Anterior face of pronotum: vertical, largely hidden in dorsal view. Lateral face of pronotum: nearly flat. Netrion: absent. Anterior margin of mesoscutum: anteriorly deflexed, meeting pronotum anteriorly. Skaphion: absent. Shape of mesoscutum in dorsal view: trapezoidal, anterior side curved. Parapsidal lines: absent. Notaulus: present, percurrent. Path of notauli: converging, closely approximat- ed posteriorly. Shape of notaulus: dilated posteriorly. Mesoscutellum shape: slightly wider than long, semicircular. Mesoscutellar armature: absent. Metascutellum shape: not posteriorly produced, present as low convex bulge. Setation of dorsal propodeum: covered by dense, fine pilosity. Lateral propodeal projection: absent, posterior margin of propodeum rounded. Mesal concavity of dorsal propodeum: broadly extending anteriorly to metanotal margin. Median keel of propodeum: absent. Lateral keels of dorsal propodeum: absent. Development of mesopleuron: large, prominent. Mesopleural depression: large, well-developed. Mesopleural carina: present, forming curved arch from near mid coxa to mesopleural pit. Mesopleural pit: present. Anterior margin of ventral mesopleuron: straight, not projecting anteriorly. Mesepimeral foveae: absent. Episternal foveae: present, indicated by arched carina connecting acetabular carina and mesopleural carina. Posterodorsal corner of mesopleuron: rounded. Metapleural triangle: clearly developed, delimited posteriorly by carina. Setation of metapleural triangle: densely, evenly setose. Metapleural pit: not visible, if present, obscured by setation. Posterior margin of metapleuron: produced posteriorly into distinct lamella. Metapleural-propodeal articulation: fused, without suture separating sclerites. Leg shape: gracile, elongate. Posterior surface of hind coxa: transversely rugulose. Trochantellus: present. Tibial setation: with only short setae. Hind tibal longitudinal carina: absent. Tibial spur formula: 1-2-2. Tarsal formula: 5-5-5. Tarsomere shape on hind leg: cylindrical. Pretarsal claws: simple.

Wings: Length of fore wing: extending beyond apex of metasoma. Wing color: hyaline. Shape of fore wing R: weakly arched. Bulla in fore wing R: absent. Fore wing R1: extending to costal margin. Pseudostigma: absent. r-rs shape: reflexed apically. r-rs origin: from R at costal margin, marginal vein therefore present. Development of R1 beyond r-rs: present, therefore postmarginal vein present, short. Fore wing Rs: indicated by darkly pigmented nebulous vein. Fore wing Rs+M (basal vein): indicated by darkly pigmented nebulous vein. Fore wing M: indicated by darkly pigmented nebulous vein. Fore wing Cu: indicated by darkly pigmented nebulous vein. Hind wing R: tracheate throughout length, extending to hamuli on costal margin.

Metasoma: Metasoma shape: short, broad. Relative sizes of metasomal segments: T2 distinctly longest segment. Number of visible terga in female: 7. Number of visible sterna in female: 6. Number of visible terga in male: 7. Number of visible sterna in male: 7. Laterotergites: present, narrow. Laterosternites: present. Base of T1: margined by transverse carina. Crenulate base of terga: T2 only. T1 horn: absent. Microsetae on T6: absent. S1 shape: evenly arched, without distinct median keel. Anterior margin of S1: transverse, not projecting anteriorly. Distribution of felt fields: S2. Cercus: present.

Diagnosis. Th e large second metasomal segment, by far the largest of all segments ( Fig. 5 ), is also found in members of the subfamilies Platygastrinae and Telenominae . Orwellium is distinguished from telenomines by the presence of narrow laterotergites and laterosternites on the metasoma and by the densely setose propodeum and metapleuron. Orwellium is distinguished from platygastrines by the presence of well-devel- oped, tracheate marginal and stigmal veins in the fore wing, the presence of a malar sulcus, and the presence of cerci.

Etymology. The name Orwellium honors the author George Orwell, the brilliant and seemingly clairvoyant writer of political science fiction, and is to be considered to be neuter in gender. The specific epithet enigmaticum refers to the initial doubts concerning the proper familial placement for this genus.

Link to Distribution Map. [http://osuc.biosci.ohio-state.edu/HymOnline/maplarge.html? id=245120]

Material Examined. Holotype female: CHILE: Los Lagos, Ahoni, Chiloé Island , 70 m, V.1988, Malaise trap, L. Masner, OSUC 163069 (deposited in CNCI, Ottawa) . Paratypes: CHILE: 118 males, 159 females, OSUC 163053–163065, 163067–163068, 163070–163071, 226381–226491, 226493–226638, 256958–256960 (CNCI, OSUC) .

Discussion. Two outstanding features of Orwellium are the number of antennomeres and the dense pilosity on the metapleuron and propodeum. Although we record here that the female antenna is comprised of ten antennomeres, A3 is extremely long and there is a noticeable constriction in its midlength. Th is seems to indicate the fusion between a former A3 and A4. Th e densely setose metapleuron and propodeum is relatively rarely seen in Platygastroidea , and then principally within the Platygastrinae . In many specimens of Orwellium (such as in Fig. 2 ), there is an appreciable amount of extraneous material embedded within the setae. Th is may simply be a trap for debris, or it may suggest the presence of an exocrine gland.

The 1-2-2 tibial spur formula is uncommonly found in the superfamily outside of the Platygastrinae . It is limited to the genera Archaeoteleia , Neuroscelio , and the tribe Sparasionini (sensu Johnson et al. 2008b) . Th ree sparasionine genera were not included in the analysis of Murphy et al. (2007), but the remainder are precisely those taxa that cluster near Platygastrinae at the base of the cladogram of the superfamily. Orwellium has a number of features that are similar to platygastrines. Th e notauli are expanded posteriorly and converge near the transscutal articulation. Orwellium lacks a netrion on the pronotum, the site of origin of the second flexor of the fore wing ( Mikó et al. 2007). The mesopleural pit ( Fig. 2 , mp) is located in a relatively low and posterior position on the mesepisternum, and connected by a groove to the apices of the mesopleural carina and sternaulus anteriorly, and to another pit (unnamed in Mikó et al. 2007) located ventrally near the posterior margin of the mesopleuron. Similar structures are found in a number of platygastrines (see illustrations in Masner and Huggert 1989), but are not yet known in the other subfamilies. Th ese similarities to platygastrines must be reconciled with another set of characters. Th e pronotum lacks the epomial and transverse pronotal carinae. The sex segment in the male is on A5, although the fact that the male has one more segment than platygastrines might suggest that the A 5 in Orwellium could be homologous with the A 4 in platygastrines in which the maximum number of antennomeres is 10. The cerci are well developed on the apical metasomatic tergite, but in platygastrines cerci are completely absent. Th e presence of the marginal, stigmal and (short) postmarginal vein ( Fig. 6 ) is completely unknown in any platygastrine. We interpret this evidence to be consistent with the hypothesis that Orwellium is the sister group of the Platygastrinae . We are currently actively working on the comprehensive morphological and molecular analysis of relationships within the superfamily that is needed to address this question.

Figures

Figures 1–6. Orwellium enigmaticum gen. n., sp. n. 1 Lateral habitus 2 Head and mesosoma, lateral view 3 Head and mesosoma, dorsal view 4 Head, anterior view 5 Metasoma, dorsal view 6 Fore wing. Scale bars in millimeters. 1–2 Paratype female, OSUC 226498. 3–5 Holotype female, OSUC 163069. 6 specimen sacrificed, not recorded in database.