Perilampus tristis, Mayr, 1905

Darling, D. Christopher & Yoo, Jeong, 2021, The Perilampidae of the United Arab Emirates and Yemen (Hymenoptera: Chalcidoidea), Zootaxa 5020 (1), pp. 101-129 : 118-122

Perilampus tristis species group

Perilampus tristis is a very distinctive European species that was inadvertently introduced into North America (see Darling 1996). This species has not been critically studied in Europe and the Palaearctic region. We recognize three species in the Arabian Peninsula, two are which are described as new and compare these species with specimens of P. tristis (identified by Bouček) and with the lectotype female (ROME181738-NHMW, Appendix 1). Species in this group are black in color with or without weak metallic iridescence and share the following features: prepectus narrow with a long ventral lobe with a row of alveolae ( Figs 8G , 10D, 10J ), petiole with a smooth or weakly rugulose raised scale ( Figs 8C , 10G , arrows), and male aedeagus with a pair of long spines ( Figs 9D, 9H , 10E, 10K , arrows). All three P. tristis group species from UAE and Yemen have incomplete propodeal plicae laterad, whereas those of the P. tristis lectotype are complete.

Perilampus rainerius (Argaman), 1990

Figures 8 , 9 , Appendix 1

Material examined. Holotype, female: Egypt, 30°11'8.71"N, 31°20'1.3"E, [Al Gabal Al Asfar], “Egitto, Gebel Asfar, 7 VI 35 , Coll. A. Mochi ” [1935] ( MSNG).

Paratype, female: same locality and collector, VII 6 1936 ( MSNG) .

Additional material examined. Egypt: 1 female, 3 males: Type locality, 7 X 34 [1934], A. Mochi (1 female: ROME181495 - NHMW, Appendix 1); 8 km S Ismailia, PM Marsh (1 male: ROME159125 - USNM) ; El Beheira, Wadi el Natrun, 23 May 1965, KV Krombein (1 male: ROME159124 - USNM) ; Faiyum, Tamiya , 29 Apr 1935, A Rabinovitch (1 male: ROME159126 - USNM) . United Arab Emirates: 28 females, 6 males. Al Houbara Protected Area , 24°00'36"N, 54°02'24"E: 1-28 Feb 2017, A Saji; A van Harten, Malaise trap (3 males: ROME176774 - ROME, ROME176775 - ROME, ROME176776 - NHMUK) ; 1-30 Apr 2016, A Saji; A van Harten, Malaise trap (1 female: ROME159088 - ROME) ; 1-30 Jun 2016, A Saji; A van Harten, Malaise trap (5 females: ROME159094 - ROME, ROME159096 - ROME, ROME159097 - ROME, ROME159098 - ROME, ROME159099 - ROME; 1 male: ROME159095 - ROME); 1-31 Mar 2016, A Saji; A van Harten, Malaise trap (2 females: ROME159084 - NHMUK, ROME159085 - ROME) ; 1-31 May 2016, A Saji; A van Harten, Malaise trap (3 females: ROME159090 - ROME, ROME159091 - ROME, ROME159092 - ROME) ; 10-31 Jan 2016, A Saji; A van Harten, Malaise trap (1 female: ROME159083 - ROME) . al-Ajban, 24°36’N, 55°01'E: 10 Oct 2005, A van Harten, Malaise trap (1 female: ROME159201 - CNC) ; 27 May-26 Jun 2006, A van Harten, Malaise trap (6 females: ROME174235 - ROME, ROME174236 - ROME, ROME174237 - ROME, ROME174238 - ROME, ROME174239 - ROME, ROME174242 - ROME) ; 30 Jan-26 Feb 2006, A van Harten, Malaise trap (2 females: ROME174243 - EAD, ROME174244 - ROME) ; 7-28 Dec 2005, A van Harten, Light trap (1 female: ROME174240 - ROME) ; 9 Nov-7 Dec 2005, A van Harten, Malaise trap (3 females: ROME159202 - CNC, ROME159204 - EAD, ROME159203 - ROME) . al-Wathba Wetland Reserve , 24°15'00"N, 54°36'36"E: 1-28 Feb 2015, A Saji; A van Harten, Malaise trap (1 male: ROME159082 - ROME) ; 20 Apr 2017, A Saji; A van Harten, Malaise trap (1 female: ROME176777 - ROME) . Dubai, Twar 3, 25°15’N, 55°24'E: Apr 2019, A Thani (1 male: ROME177269 - ROME) ; Dec 2018 - Feb 2019, A Thani (1 female: ROME177270 - ROME) . Wadi Hayl , 25°05’N, 56°13'E: 28 Mar 2007, A Stark; F Menzel, Sweeping (1 female: ROME174223 - ROME) . Yemen: 2 females. Al Hudaydah, Al Kadan , 15°16'0"N, 43°12'0"E: 17 Feb-31 Mar 1998, A van Harten; HM Naser, Malaise trap (1 female: ROME159200 - EAD) . Sana'a, 12 Km NW Manakhah , 15°5'0"N, 43°42'0"E: 3 Jul-21 Aug 2001, A van Harten, Malaise trap (1 female: ROME159197 - ROME) .

Redescription. Female. Length: approximately 1.2–2.6 mm. Color: black, without iridescent reflections, or mesonotum with bronze reflections ( Fig. 9A ), metasoma black or brown, dorsellum black with coppery red or bronze reflections. Legs: coxae black, hind femora black or brown, pro and meso femora and tibiae brown, lighter distad and on inner surfaces, with weak blue reflections, tarsi brown. Antennae: scape brown with weak iridescence, lighter distad, pedicel brown, flagellum yellow.

Head ( Figs 8E, 8F ): in frontal view quadrate ( Fig. 8F ), slightly wider than high, HW/HH approximately 1.2, sparsely setose to smooth; in dorsal view weakly transverse ( Fig. 8E ), width greater than twice length, HW/HL 2.2‒2.3; slightly wider than pronotum, HW/PW approximately 1.1‒1.2. Frontal carina: absent. Scrobal cavity: shallow, with weak round swelling originating from between median and lateral ocelli extend towards eye margin. Ocelli: large; forming a wide triangle, POL about twice distance between posterior and anterior ocelli; POL very long,>2.5× OOL. Vertex: rounded behind; smooth, interocellar region with long groove originating from occiput to median ocellus ( Fig. 8E , arrow); occiput with median furrow delimited below vertex ( Fig. 8B , arrow), with costulae. Outer orbits: smooth, strong costulae behind. Inner orbits: in lateral view, nearly parallel to inner eye margin; smooth. Malar space: long, greater than 0.25× eye height, MS/EH approximately 0.3; malar sulcus distinct; smooth. Clypeus: weakly transverse, wider than high, CW/ CH approximately 1.7‒1.8, trapezoidal, lateral sulci weak and straight, weakly divergent; epistomal sulcus straight or weakly concave, same strength as lateral sulci, only slightly extended ventrad; lower margin convex. Supraclypeal area: subquadrate.Antenna: scape length approximately 0.6× EH; anellus length approximately 0.1× PL; F1 subquadrate, subequal in length to pedicel, F1L/PL approximately 0.9, F2 subquadrate, F3–F7 transverse; clava 4-segmented, with distinct terminal button.

Mesosoma ( Figs 8B, 8C, 8D, 8G ): length approximately 1.2–1.3× maximum width. Pronotum in dorsal view: short, about 0.25× length of mesoscutum, PN/MSC 0.2‒0.3; shorter along midline, 0.5‒0.6× length laterad; anterior margin sharp, the first row of punctures slightly lower; without flange on lateral panel of pronotum the level of mesothoracic spiracle. Lateral panel of pronotum ( Fig. 8G ): slightly wider than prepectus, LPP/PPT approximately 1.2‒1.3; flat, with 3 rows of punctures and wide coriarious interspaces dorsad, ventrad with wide coriarious patch; anterior margin slightly rounded; posterior margin ventrad grooved, with row of alveolae. Prepectus: narrow; differentiated from pronotum, with distinct suture; ventral strap long ( Fig. 8G , arrow), with row of alveolae; central area smooth, with foveae along dorsal and posterior margins. Femoral depression: nearly smooth. Midlobe of mesoscutum ( Fig. 8B ): without transverse tubercle; punctures rounded to weakly angulate, with very wide and coriarious interspaces. Lateral lobe of mesoscutum: smooth dorsad; coriarious-punctate laterad. Scutellum: about as long as mesoscutum, SC/MSC approximately 1.1; posterior margin smoothly rounded; punctures rounded to weakly angulate, with very wide and coriarious interspaces. Axilla: punctate dorsad, imbricate below. Axillula: short 0.3× width of propodeum; submedian area shagreened to smooth, with weak groove along median carina; smooth laterad; plicae incomplete laterad, delimited ventrad by plicae, dorsad by transverse band of foveae; propodeal spiracle margin narrowly foveate ventrad; nucha rugulose. Fore wing ( Fig. 8D ): postmarginal vein very short, 0.5‒0.6× length of marginal vein, 0.8‒1.0× length of stigmal vein; stigmal vein with weak uncus.

Metasoma ( Figs 8C, 8H ): petiole short with large smooth to weakly rugulose raised scale ( Fig. 8C , arrow); Gt2 imbricate or smooth, posterior margin weakly concave at middle; Gt3 smooth or weakly imbricate dorsad.

Male. Length: approximately 1.5‒1.6 mm. Color: as in female, except flagellum and tarsi brown or white. Structure and sculpture as in female except as follows: Ocelli ( Figs 9B, 9F ): larger. Malar space: the same or shorter. Scape ( Figs 9C, 9G ): about 0.5‒0.6× EH; stout, length about 4.5× width above radicle; strongly expanded distad, about 1.4× width above radicle; punctures covering about 0.5 scape length, with wide interspaces. Mesosoma: slightly more elongate, length approximately 1.3‒1.4× maximum width. Aedeagus ( Figs 9D, 9H , arrows): with paired lateral spines.

Variation. Assessing variation in this species is complicated because there is considerable size variation (approximately 1.3‒2.6 mm) in the specimens from UAE. The degree of iridescence on the mesonotum and imbricate sculpture on the Gt3 varies with body length. Larger specimens (approximately 2‒2.6 mm) have cupreous iridescence on the mesonotum ( Fig. 9A ) and imbricate sculpture on Gt3 ( Fig. 8H ). These characters become weaker as body size becomes smaller and are completely absent in specimens smaller than approximately 1.8 mm ( Fig. 8B ). Interestingly, one female (ROME159082) has blue iridescence on the mesonotum ( Fig. 9E ) and one male (ROME159094) has a quadrate head in the dorsal view ( Fig. 9B cf. Fig. 9F )

Diagnosis. Perilampus rainerius is distinguished from P. yemenensis and P. houbaraensis by its short postmarginal vein, not longer than the stigmal vein ( Fig. 8D ), a distinct suture between pronotum and prepectus ( Fig. 8G ), mesonotum with small and round punctures with wider coriarious interspaces ( Figs 8B , 9A, 9E ), and stout male scape with large punctures covering 0.5 scape length ( Figs 9C, 9G ).

Remarks. Other than body size, we can find no reliable characters to separate the Egyptian and Arabian Peninsula specimens here referred to P. rainerius . The original description of this species was apparently based on three females from Egypt and we have compared a topotypic female and males from Egypt to the long series of males and females from the UAE and describe for the first time the male of this species based on specimens from both Egypt and the UAE.

Figures

FIGURE 8. Perilampus rainerius. A, habitus, lateral view; B, habitus, dorsal view; C, propodeum; D, fore wing; E, head, dorsal view; F, head, frontal view; G, prepectus; H, Gt3. [A‒G: ROME159094; H: ROME159204]

FIGURE 9. Perilampus rainerius. A, mesosoma, dorsal view; B, head, dorsal view, male; C, scape, male; D, aedeagus, male, dorsal view; E, mesosoma, dorsal view; F, head, dorsal view, male; G, scape, male; H, aedeagus, male, dorsal view. [A: ROME159204; B‒D: ROME159095; E: ROME159082; F‒H: ROME176774]

FIGURE 10. Perilampus yemenensis and P. houbaraensis. A‒F, P. yemenensis: A, habitus, lateral view; B, head, dorsal view; C, lower face sculpture; D, prepectus; E, propodeum; F, fore wing venation. G‒L, P. houbaraensis: G, habitus, lateral view; H, head, dorsal view; I, lower face sculpture; J, prepectus; K, propodeum; L, fore wing venation. [A‒F: Holotype, ROME159199; G‒L: Holotype, ROME159089]