Perilampus seneca Yoo & Darling, 2024

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 seneca Yoo & Darling sp. nov.

Figs 16 , 17

Type locality.

Canada, Ontario, Chaffey’s Locks.

Type material.

Holotype. “ CANADA, ONT: Frontenac Co., Chaffey’s Locks Oct. 6, 1987 DC Darling. Ex: birch ”, “ LAB REARED Ex: tachinid parasite of Hyphantria cunea ”. The holotype is point-mounted ( Female ROME 183977 , ROME). BOLD: ACF 3436 . ROM Online Collection.

Paratypes. Canada: 1 male. Ontario: 1 male. Essex Co., Windsor : (1 male: ROME 162263 - ROME; BOLD: ACF 3436 ; ITS 2 ) . USA: 5 females, 1 male. Indiana: 1 female. Posey Co., Harmonie State Park : (1 female: ROME 182769 - TAMU; BOLD: ACF 3436 ; ITS 2 ) . Kentucky: 1 female, 1 male. Jessamine Co., S. of Nicholasville , 37°47'4"N, 84°34'11"W: (1 female: ROME 158541 - ROME; BOLD: ACF 3436 ; ITS 2 ) . Missouri: 1 female. St. Louis Co., St. Louis : (1 female: ROME 185906 - ROME; BOLD: ACF 3436 ; ITS 2) . Texas: 1 female. Walker Co., Huntsville : (1 female: ROME 185911 - TAMU; BOLD: ACF 3436 ; ITS 2) . West Virginia: 1 female. Hardy Co., 3 mi NE Mathias , 38.9098, -78.8881: (1 female: ROME 198142 - USNM; BOLD: ACF 3436 ; ITS 2 ) .

Material examined.

Canada: 13 females, 17 males. USA: 38 females, 29 males. (Suppl. materials).

Additional material examined.

USA: 2 females, 3 males. Florida: 2 females, 3 males. Alachua Co., Gainesville : (1 male: ROME 204136 - SEMC). (2 males: ROME 207380 - FSCA; ROME 207381 - FSCA) . Orange Co., Orlando, UCF Campus : (1 female: ROME 152729 - UCFC; BOLD: ACF 3436 ; ITS 2) . Walt Disney World, Sec 16 T 24 S R 27 E : (1 female: ROME 152728 - UCFC; BOLD: ACF 3436 ; ITS 2) .

Etymology.

The specific epithet is a noun in apposition — a reference to both the Seneca people who are the original inhabitants of the core range of the species and to the county in New York State where most of the specimens were reared.

Description.

Female (Fig. 16 ). Length: 2.9–4.4 mm. Color: head iridescent greenish blue or violet with black coloration between lateral ocellus and frontal carina (Fig. 16 G , arrow); mesosoma, and metasoma iridescent greenish blue or violet; clypeus ventral margin black (Fig. 16 I ); antenna with scape and pedicel weakly iridescent greenish blue or violet, flagellum brown or black, lighter ventrad and distad.

Head (Fig. 16 G – J ): 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 1.5–1.7; distance from lateral ocellus short, FCLO / LOD 0.5–0.6. Scrobal cavity (Fig. 16 H ): in anterior view wide, SW / HW about 0.5. Ocelli (Fig. 16 G ): a line between anterior margin of lateral ocelli touching anterior margin of median ocellus. POL / OOL 1.9–2.1. Ocellar ratios LOD: POL: OOL: LOL 1, 2.9–3.2, 1.5–1.8, 1.0–1.2. 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 0.2–0.3; sculpture strongly to weakly striate, without large piliferous punctures. Gena (Fig. 16 J ): mostly striate along outer eye margin with narrow and short smooth area, striate behind. Malar space: MSL / EH about 0.2. Lower face (Fig. 16 H, I ): with setae sparse or dense and narrowly distributed laterad torulus, and sparse or dense below. Clypeus (Fig. 16 I ): CW / CH 1.3–1.4; ventral margin concave; setae evenly distributed, or with small bare area without setae medially.

Mesosoma (Fig. 16 B – F, K, L ): Lateral panel of pronotum: slightly narrower than or about as wide as prepectus, LPP / PPT 0.7–0.9; usually with small triangular flange below level of mesothoracic spiracle in posterior oblique view (Fig. 16 D , arrow). Mesofemoral depression: usually smooth (Fig. 16 L ), rarely weakly rugulose or weakly imbricate ventrad. Mesoscutum: punctures angulate, with narrow and weakly coriarious interspaces (Fig. 16 B ); lateral lobe smooth or weakly coriarious along notaulus (Fig. 16 C ); parascutal carina broadly curved, acuminate (Fig. 16 E ). Mesoscutellum: apex with inner margins gradually diverging (Fig. 16 K ); punctures angulate, with narrow and weakly coriarious interspaces. Axilla (Fig. 16 F ): in lateral view imbricate dorsad and carinate ventrad. Axillula: smooth dorsad. Fore wing: stigma small, 2.0–2.5 × as wide as postmarginal vein.

Male (Fig. 17 ). Length: usually smaller, 1.6–3.3 mm. As in female, except: Color: mesonotum with strong or weak cupreous iridescence, and mesoscutellum cupreous laterad (Fig. 17 E ). Frontal carina: distance from lateral ocellus as wide or shorter, FCLO / LOD 0.3–0.5. Scape (Fig. 17 G, H ): pits dense, covering 0.3–0.4 × scape length. Lateral panel of pronotum: shape below level of mesothoracic spiracle as in female or with large triangular flange.

Diagnosis.

Perilampus seneca is most similar to P. ute , but females can be distinguished by the lateral panel of pronotum which has a small triangular flange (Fig. 16 D , arrow cf. Fig. 18 D , arrow), and black coloration between the frontal carina and lateral ocelli (Fig. 14 G , arrow cf. Fig. 18 G ). Males of this species can often be differentiated from those of P. ute by a smaller flange on the pronotum (Fig. 17 B cf. Fig. 19 B, C ). Males of P. seneca with a large triangular flange on the pronotum are similar to those of P. ute , but differ in having cupreous iridescence on a mesonotum (Fig. 17 E cf. Fig. 19 F ). Males of P. seneca with a small or no flange on lateral panel of pronotum can be confused with P. sonora , which also has the strongly cupreous mesonotum (Fig. 17 A, E cf. Fig. 23 A ), but can be distinguished by a densely pitted scape (Fig. 17 G, H cf. Fig. 23 G, H ). In addition, the distribution of P. seneca extends to southeastern Canada and eastern USA, while P. ute is restricted to the southwestern and central USA.

Distribution

(Fig. 25 D ). Southeastern Canada, and central and eastern USA: Canada (Ontario), USA (Arkansas, Arizona, Georgia, Indiana, Kentucky, Maryland, Massachusetts, Missouri, New York, Texas, Virginia, West Virginia, Wisconsin). Possibly southeastern USA and Mexico: USA (Florida), Mexico (Veracruz).

Host association.

Perilampus seneca is a hyperparasitoid, primarily parasitizing dipteran and hymenopteran parasitoids of Lepidoptera (Fig. 26 F ), rarely parasitizing dipteran parasitoids of Orthoptera and Coleoptera . Tachinidae ( Diptera ). Lespesia melalophae (Allen) from Lepidoptera . Ormia sp. from Amblycorypha oblongifolia ( Tettigoniidae ) ( ROME 162263). Tachinids from H. cunea and Chrysomelidae ( ROME 174210). Braconidae ( Hymenoptera ). Cotesia hyphantriae (Riley) from Hyphantria cunea (Drury) ( Erebidae ). Unidentified parasitoids from Euchaetes egle (Drury) ( Erebidae ).

Variation.

An unsequenced male from Florida ( ROME 204136), has a violet mesonotum and two sequenced females from Florida ( ROME 152728, ROME 152729) lack black coloration between the frontal carina and median ocellus. And two unsequenced males from Florida ( ROME 207380, ROME 207381) reared from Anisomorpha buprestoides ( Pseudophasmatidae , Phasmida ) have a violet mesonotum and the lateral lobe of mesoscutum is weakly punctate along notaulus.

Remarks.

There are uncertainties about the species limit of P. seneca . Although P. seneca is differentiated from the other Nearctic species in COI (10 BINed specimens on BOLD, ACF 3436), there are Neotropical clades (from Argentina, Costa Rica, and Venezuela) with BIN ACF 3436 that cannot be delimited from P. seneca and each other. Specimens either morphologically indistinguishable from P. seneca (“ P. hyalinus 1 ” from Costa Rica and Venezuela) or differ only in the body coloration or subtle male scape morphology (“ P. hyalinus 2, 3, and 16, from Argentina, Costa Rica, and Venezuela, respectively). Perilampus seneca and these Neotropical groups are placed together as a single clade in COI (Suppl. material 2). Interestingly, P. seneca is rendered paraphyletic by P. hyalinus 2 from Argentina which itself is polyphyletic — the first clade of P. seneca is the population from Florida, and the second is the northern population. ITS 2 does not support the species delimitation and relationships suggested by COI (Suppl. material 2) — each Neotropical group is delimited as reciprocally monophyletic species and show different or unresolved species relationships, and P. seneca is an unresolved polytomy. And P. seneca cannot be morphologically distinguished from the types of P. americanus Girault and P. nigriviridis Girault , both from Paraguay, based on the images provided by ZMHB (Fig. 24 D – F ).

Despite these uncertainties we hypothesize that P. seneca is a recently diverged Nearctic species distinct from the Neotropical groups with similar COI sequences — the populations north of Florida are monophyletic for COI albeit with poor support in BI (Suppl. materials 2, 3: BS = 71, PP = 0.53). And P. seneca is differentiated from the aforementioned Neotropical groups by ITS 2 (Suppl. material 2). The polytomy in the ITS 2 trees could be a “ soft polytomy ” caused by insufficient information from a single gene that can only be resolved with additional genetic data ( Maddison 1989). There are ten BINed specimens on BOLD ( ACF 3436) from the Nearctic region.

The relationships between P. seneca and the Neotropical specimens shown in COI unsupported by ITS 2 may be due to retention of ancestral polymorphism via incomplete lineage sorting ( ILS), introgression events between the Neotropical lineages, and / or insufficient phylogenetic information in ITS 2 for this group. The paraphyly of P. seneca may be explained by ILS instead of hybridization due to the geographical distance between the two groups. However, two females from Florida ( ROME 152729, ROME 152728) without black coloration between the frontal carina and lateral ocellus, and unsequenced males from Florida ( ROME 204136, ROME 207380, ROME 207381) with entirely violet body color in contrast to cupreous body color of northern P. seneca suggest there could be two independently evolving lineages in the Nearctic region.

A single Perilampus was reared as a parasitoid of Tachinidae in Kentucky, USA ( ROME 174210) from a series of 1,139 tachinid primary parasitoids of Acalymma vittatum and Diabrotica undecimpunctata howardi ( Chrysomelidae ) ( Skidmore 2018). This is the only Nearctic P. hyalinus species complex specimen associated with Coleoptera and is most likely the result of the accidental entry of a planidium into a novel but suitable host, and does not contradict the host preference of P. seneca for the parasitoids of Lepidoptera .

Figures

Figure 14. Perilampus pilosus 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 parascutal carina F axilla G head, dorsal view H head, anterior view I lower face J head, lateral view K mesoscutellum apex L mesofemoral depression. [A, H Holotype, ROME 182765; B, C, E – G, L Paratype, ROME 182819; I, J Paratype, ROME 189067; K ROME 189129; L Paratype, ROME 152679]. Scale bar: 1 mm (A).

Figure 16. Perilampus seneca 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 parascutal carina F axilla G head, dorsal view H head, anterior view I lower face J head, lateral view K mesoscutellum apex L mesofemoral depression. [A, H, I, J, L Paratype, ROME 199563; B, F, G Paratype, ROME 182769; C Paratype, ROME 158541; D Paratype, ROME 199544; E Holotype, ROME 183977; K Paratype, ROME 198142]. Scale bar: 1 mm (A).

Figure 17. Perilampus seneca Male A habitus, lateral view B lateral panel of pronotum, parascutal carina, and axilla, posterior oblique view C head, anterior view D head, dorsal view E habitus, dorsal view F lateral lobe of mesoscutum along notaulus G, H scape. [A – C, F, G Paratype, ROME 183976; D Paratype, ROME 199551; E Paratype, ROME 162263; H Paratype, ROME 199552]. Scale bars: 1 mm (A); 100 μm (G, H).

Figure 18. Perilampus ute Female A habitus, lateral view B habitus, dorsal view C lateral lobe of mesoscutum along notaulus D, E lateral panel of pronotum, posterior oblique view F axilla G head, dorsal view H head, anterior view I lower face J head, lateral view K mesoscutellum apex L mesofemoral depression. [A, C, D, F, G, H Holotype, ROME 182768; B, E, I – L Paratype, ROME 182763]. Scale bar: 1 mm (A).

Figure 19. Perilampus ute Male A habitus, lateral view B, C lateral panel of pronotum, posterior oblique view D head, anterior view E head, dorsal view F habitus, dorsal view G lateral lobe of mesoscutum along notaulus H, I Scape. [A, B, D – F, H Paratype, ROME 182781; C, G, I Paratype, ROME 198139]. Scale bars: 1 mm (A); 100 μm (H, I).

Figure 23. Perilampus sonora Male A habitus, lateral view B lateral panel of pronotum, parascutal carina, and axilla, 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 – F, G Paratype, ROME 182754; H Paratype, ROME 198215]. Scale bars: 1 mm (A); 100 μm (G, H).

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).

Figure 26. Cocoons, pupa, and host remains associated with reared specimens of Perilampus. A – C, E Neodiprion lecontei cocoons A, B P. neodiprioni as primary parasitoid C, E P. neodiprioni as hyperparasitoid, parasitoid of Ichneumonidae D Neodiprion virginianus cocoon, P. neodiprioni as hyperparasitoid, parasitoid of Tachinidae [insert: tachinid puparium spiracles] F Lepidoptera pupa, P. seneca as hyperparasitoid, parasitoid of Tachinidae G, H Monoctenus suffusus cocoons G P. monocteni as primary parasitoid H P. monocteni as hyperparasitoid, parasitoid of Tachinidae [insert: tachinid puparium spiracles]. Abbreviations: eh, emergence hole; ex, Perilampus pupa exuvia; Ic, ichneumonid cocoon; Lp, lepidopteran pupa; M, Monoctenus remains; Mc, Monoctenus cocoon; N, Neodiprion remains; Nc, Neodiprion cocoon; Tp, tachinid puparium. [associated Perilampus: A, B ROME 207376 C ROME 207377 D ROME 198223 E ROME 162273 F ROME 202000 G ROME 207330 H ROME 207328]. Scale bars: 1 mm.