Perilampus hyalinus Say, 1929

Yoo, Jeong Jae & Darling, D. Christopher, 2024, Integrative taxonomic revision of the Nearctic Perilampus hyalinus species complex (Hymenoptera, Chalcidoidea, Perilampidae) resolves 100 years of confusion about the host associations of P. hyalinus Say, Journal of Hymenoptera Research 97, pp. 1301-1383 : 1301-1383

Perilampus hyalinus Say rev. stat.

Figs 4 , 5 , 24 A, B

Perilampus hyalinus Say, 1829: 79. (original description, sex not indicated). Type locality: USA, Pennsylvania. Type material: Type lost. Neotype. “ USA: OH: Montgomery Co. New Carlisle 39.989583, -84.029056, Ex. Ceracia dentate, Ex. Melanoplus femurrubrum prob. 26. x. 2014 M. D. Sheaffer ”. The neotype is point-mounted (Male ROME 204130, USNM). BOLD: AEA 0382. ROM Online Collection.

Perilampus entellus Walker, 1843: 103 (original description). Type locality: Ohio, USA. Type Material. Lectotype, B. M. Type Hym. 5.2285, NHMUK 014583126 (Images examined).

Perilampus aciculatus Provancher, 1889: 199 (original description). Type locality: Ottawa, Canada. Type material. Lectotype, 1359, Université Laval , Québec City, Canada (Images examined). Note: Year of publication incorrect as 1887 in subsequent references to P. aciculatus (see Barron 1975: 391).

Perilampus aciculatus , Lectotype, Gahan and Rohwer 1918: 106.

Perilampus aciculatus Smuylan, 1936: 380 (tentative synonym of P. hyalinus Say ).

Perilampus aciculatus Peck, 1963: 519 (subjective synonym of P. hyalinus Say).

Perilampus aciculatus Burks, 1963: 1259 (subjective synonymy “ probably correct ”).

Perilampus entellus , Lectotype, Burks 1975: 150 (subjective synonym of P. hyalinus Say ).

Taltonos hyalinus (Say). Argaman, 1990: 205 (new combination).

Taltonos aciculatus (Provancher) , Argaman, 1991: 5 (new combination).

Taltonos entellus (Walker) , Argaman, 1991: 9 (new combination).

Perilampus hyalinus Say. Darling, 1996: 113 ( Taltonos, subjective synonym of Perilampus).

Perilampus aciculatus Darling, 1996: 113 ( Taltonos, subjective synonym of Perilampus).

Perilampus entellus Darling, 1996: 113 ( Taltonos, subjective synonym of Perilampus).

Perilampus aciculatus , New synonymy based on Neotype designation herein.

Perilampus entellus , New synonymy based on Neotype designation herein.

Material examined.

Canada: 77 females, 47 males. USA: 67 females, 31 males. (Suppl. materials).

Additional material examined.

Canada: 1 female. Ontario: 1 female. Durham R. M., Glen Major Forest: (1 female: ROME 152664 - ROME; BOLD: AEA 0382; ITS 2). Mexico: 2 females. Jalisco: 1 female. (1 female: ROME 200751 - HNHM). Sonora: 1 female. (1 female: ROME 162260 - USNM).

Description.

Female (Fig. 4 ). Length: 2.9–4.4 mm. Color: head iridescent greenish blue or violet; mesosoma and metasoma iridescent greenish blue or violet; clypeus ventral margin black (Fig. 4 I ); antenna with scape and pedicel weakly iridescent greenish blue or violet, flagellum brown or black, lighter ventrad and distad.

Head (Fig. 4 G – I ): in dorsal view transverse, width slightly greater than twice length, HW / HL 2.1–2.2. Frontal carina: in anterior view straight to weakly sinuate below midlevel of eye; in dorsal view gradually narrowed V shape around median ocellus, FC / MOD 1.5–1.9; distance from lateral ocellus short to long, FCLO / LOD 0.6–1.0. Scrobal cavity (Fig. 4 H ): in anterior view wide, SW / HW about 0.5. Ocelli (Fig. 4 G ): a line between anterior margin of lateral ocelli nearly bisecting median ocellus. POL / OOL 1.7–1.9. Ocellar ratios LOD: POL: OOL: LOL 1, 3.3–3.5, 1.8–2.0, 1.2–1.4. Vertex: with strong to weak transverse striations, without large piliferous punctures. Parascrobal area: in lateral view gradually narrowed towards lower eye margin; width narrow, PSW / EL about 0.3; sculpture strongly to weakly striate, without large piliferous punctures. Gena: entirely or mostly striate along outer eye margin with narrow and short smooth area, striate behind. Malar space: MSL / EH 0.2–0.3. Lower face (Fig. 4 H, I ): with setae sparse laterad torulus, and usually sparse below. Clypeus (Fig. 4 I ): CW / CH 1.3–1.5; ventral margin concave; setae evenly distributed, or with small bare area without setae medially.

Mesosoma (Fig. 4 B – F, J – M ): Lateral panel of pronotum: slightly narrower than or about as wide as prepectus, LPP / PPT 0.7–0.9; without flange below level of mesothoracic spiracle in posterior oblique view (Fig. 4 D ). Mesofemoral depression: smooth, weakly imbricate (Fig. 4 L ), or rugulose (Fig. 4 M ). Mesoscutum: punctures angulate, with narrow or slightly wide and weakly coriarious interspaces (Fig. 4 B ); lateral lobe usually weakly punctate with coriarious or smooth interspaces along notaulus (Fig. 4 C ); parascutal carina broadly curved, acuminate (Fig. 4 J ). Mesoscutellum: apex with inner margin gradually or abruptly diverging (Fig. 4 K ); punctures angulate, with narrow or slightly wide and weakly coriarious interspaces. Axilla (Fig. 4 F ): in lateral view imbricate dorsad and rugose-areolate or carinate ventrad. Axillula (Fig. 4 E ): smooth dorsad. Fore wing: stigma small, 2.0–2.5 × as wide as postmarginal vein.

Male (Fig. 5 ). Length: usually smaller, 2.6–3.8 mm. As in female, except: Color: mesonotum sometimes with weak cupreous iridescence. Frontal carina (Fig. 5 D ): distance from lateral ocellus shorter, FCLO / LOD 0.5–0.6. Scape (Fig. 5 G, H ): pits sparse, covering 0.3–0.4 × scape length.

Diagnosis.

Perilampus hyalinus is morphologically similar to P. neodiprioni , but the axillula is always smooth dorsad without piliferous punctures (Fig. 4 E cf. Fig. 8 E ), the sculpture of the mesofemoral groove is usually smooth to weakly imbricate or rugulose (Fig. 4 L, M cf. Fig. 8 L, M ), and the inner margins of the apex of the mesoscutellum are often abruptly diverged (Fig. 4 K cf. Fig. 8 K ).

Distribution

(Fig. 25 A ). Throughout USA and southern Canada, and possibly western Mexico: Canada (Alberta, British Columbia, Manitoba, New Brunswick, Ontario, Quebec), USA (Arizona, Colorado, Illinois, Indiana, Kansas, Maryland, Montana, New York, North Dakoda, Oklahoma, Pennsylvania, Utah, Washington, Wisconsin), Mexico (Sonora, Jalisco).

Host associations.

Perilampus hyalinus is a hyperparasitoid, attacking dipteran parasitoids of Orthoptera and dipteran kleptoparasites of Crabronidae and Sphecidae provisioning with Orthoptera and rarely parasitoids of dipteran parasitoids attacking Phasmida ( ROME 204120). Hosts: Tachinidae ( Diptera ). Ceracia dentata (Coquillett) from Melanoplus femurrubrum (De Geer) ( Acrididae ). Tachinidae from Phasmatidae . Sarcophagidae ( Diptera ). Sarcophaga sp. from Melanoplus sanguinipes (Fabricius) . Sarcophagids from Tettigoniidae and Oecanthinae collected in the nests of Isodontia mexicana (Saussure) ( Sphecidae ) ( Medler 1965). Senotainia trilineata (Wulp) and S. vigilans Allen from nests of Tachysphex terminatus (Smith) and T. validus Cresson (Crabronidae) ( Spofford and Kurczewski 1984) . Possibly Nemestrinidae ( Diptera ) from M. sanguinipes . Unidentified Diptera from Melanoplus differentialis (Thomas) . Unidentified parasitoid of Orphullela sp. ( Acrididae ).

Variation.

A female from Ontario ( ROME 152664), Canada, has a smooth vertex. COI and ITS 2 suggest that this specimen is a rare morphological variant of P. hyalinus .

Remarks.

The identity of P. hyalinus has long been obscured by the presumed lost type specimen ( Mawdsley 1993) and the morphological similarity of specimens exhibiting different parasitism strategies and host associations ( Burks 1979). Say’s (1829) original description contains neither host information nor sufficient details on morphology for determining with certainty which of the Nearctic species treated herein should be regarded as P. hyalinus Say. To clarify this situation a neotype is designated herein, a reared specimen collected near the original type locality (Pennsylvania) which establishes this species as a parasitoid of dipteran parasitoids and dipteran kleptoparasites associated with Orthoptera . This species is supported by molecular analyses in both genes (Fig. 1 , Suppl. material 5) and there are 14 BINed specimens, including the neotype on BOLD ( AEA 0382) collected and reared from throughout the range of this species. Perilampus hyalinus Say is the most abundant species in collections in the eastern Nearctic region. This species is morphologically close to P. neodiprioni , and can usually be distinguished by the sculpture of its axillula dorsad and mesofemoral groove. However, these characters are not always reliable distinguishing these two species (see Remarks in P. neodiprioni ). While these characters are not always reliable distinguishing these two species, they are clearly differentiated in both COI and ITS 2 (Fig. 1 )

Figures

Figure 1. Maximum likelihood tree of Perilampus hyalinus species group retrieved from the combined analysis of COI and ITS 2 (modified from Yoo 2023). Bootstrap support values are shown on the left side of the nodes. The roman numerals and black dots adjacent to the nodes indicate the major morphological clades recovered as monophyletic (I = P. hyalinus species group; II = P. carolinensis species complex; IIa = “ pseudocarolinensis ” clade; IIb = P. carolinensis clade; III = P. hyalinus species complex; IIIa = P. hyalinus clade 1; IIIb = P. hyalinus clade 2; IIIc = P. hyalinus clade 3; IIId = “ regalishyalinus ” clade. The morphospecies designation for the sequences is marked by vertical bars, colored according to their placements within their respective morphological subgroups. The names of the species described herein are indicated in white boxes.

Figure 4. Perilampus hyalinus Female A habitus, lateral view B habitus dorsal view C lateral lobe of mesoscutum along notaulus D lateral panel of pronotum, posterior oblique view E axillula F axilla G head, dorsal view H head, anterior view I lower face J parascutal carina K mesoscutellum apex L, M mesofemoral depression. [A ROME 185913; B, K ROME 189058; C, M ROME 185947; D, F ROME 189056; E, G ROME 162229; H ROME 167636; I ROME 189060; L ROME 162246]. Scale bar: 1 mm (A).

Figure 5. Perilampus hyalinus Male A habitus, lateral view B lateral panel of pronotum and parascutal carina, posterior oblique view C head, anterior view D head, dorsal view E lower face F lateral lobe of mesoscutum along notaulus G, H scape. [A Neotype, ROME 204130; B – D, F, G ROME 182798; E ROME 167638; H ROME 189059]. Scale bars: 1 mm (A); 100 μm (G, H).

Figure 8. Perilampus neodiprioni Female A habitus, lateral view B habitus, dorsal view C lateral lobe of mesoscutum along notaulus D lateral panel of pronotum, posterior oblique view E axillula F axilla G head, dorsal view H head, anterior view I clypeus J parascutal carina K mesoscutellum apex L, M mesofemoral depression. [A – E, G, H, J, L Paratype, ROME 162273; F, M Paratype, ROME 198146; I ROME 181757; K ROME 189061]. Scale bar: 1 mm (A).

Figure 24. Type specimens of the previously described species of the Perilampus hyalinus species complex A P. entellus Walker (synonym of P. hyalinus Say), lectotype, female B P. aciculatus Provancher (synonym of P. hyalinus Say), lectotype, male C P. sirsiris (Argaman), holotype, female D P. americanus Girault, holotype, female E, F P. nigriviridis Girault, lectotype, male. Photo credits: A © The Trustees of the Natural History Museum, London (Licensed under CC BY 4.0) B Joseph Moisan-De Serres (Ministry of Agriculture, Fisheries and Food in Québec) C National Museum of Natural History, Paris D, E, F Museum of Natural History, Berlin.

Figure 25. Distribution of the Nearctic species of the Perilampus hyalinus species complex A P. hyalinus (green circles) and P. crassus (red squares) B P. neodiprioni (cyan circles) P. monocteni (red stars) C P. sirsiris D P. seneca E P. arcus F P. pilosus (yellow stars) P. ute (blue triangles) P. sonora (red circles).