Regiscolia alecto (Smith, 1858), 2025

Castagnet, Jean-Baptiste & Cabon, Flavien, 2025, Review of the genus Megascolia Betrem, 1928 (Hymenoptera, Scoliidae), Zootaxa 5700 (1), pp. 1-127 : 51-59

publication ID

https://doi.org/10.11646/zootaxa.5700.1.1

publication LSID

lsid:zoobank.org:pub:5589FAA6-35E7-4830-82A5-620339E38448

persistent identifier

https://treatment.plazi.org/id/03B687D7-FFAC-FF9D-63E4-09B0FA04D7D7

treatment provided by

Plazi

scientific name

Regiscolia alecto (Smith, 1858)
status

comb. nov.

Regiscolia alecto (Smith, 1858) , comb. nov.

( Figs 49–54 View FIGURE 49 View FIGURE 50 View FIGURE 51 View FIGURE 52 View FIGURE 53 View FIGURE 54 )

Scolia alecto Smith, 1858b: 10 ( lectotype, ♀, Makian, designated by Betrem 1928: 237; deposited in OUMNH, United Kingdoms,

not examined); Kirby 1889: 446. Scolia cincta Smith, 1858a: 89 . Scolia ( Triscolia) cincta : Saussure & Sichel 1864: 45; Cameron 1892: 101. Scolia ( Triscolia) alecto : Saussure & Sichel 1864: 48; Betrem 1941: 118. Scolia View in CoL ( Scolia View in CoL , Triscolia ) alecto : Dalla-Torre 1897: 145. Scolia View in CoL ( Scolia View in CoL , Triscolia ) cincta : Dalla-Torre 1897: 152. Scolia ( Triscolia) philippinensis Rohwer, 1921: 77–78 ; Betrem 1941: 118. Syn. nov. Triscolia alecto : Micha 1927: 123, 148. Triscolia alecto alecto : Micha 1927: 123. Triscolia philippinensis : Micha 1927: 124, 148. Triscolia philippinensis philippinensis : Micha 1927: 124, 150. Triscolia cincta : Micha 1927: 141. Scolia View in CoL ( Triscolia sectio Triscolia ) alecto cincta : Betrem 1928: 226. Scolia View in CoL ( Triscolia sectio Triscolia ) philippinensis : Betrem 1928: 236. Scolia View in CoL ( Triscolia sectio Triscolia ) alecto : Betrem 1928: 237. Megascolia ( Regiscolia) alecto : Betrem & Bradley 1964: 443; Osten 2005b: 26. Megascolia ( Regiscolia) alecto alecto : Betrem & Bradley 1964: 443; Bradley & Betrem 1967: 296; Osten 2005b: 26. Megascolia ( Regiscolia) alecto regnatrix Betrem & Bradley, 1964: 443 ; Bradley & Betrem 1967: 300; Bradley 1973a: 287;

Osten 2005b: 26 ( nomen novum for Scolia cincta Smith, 1858 ). Megascolia ( Regiscolia) philippinensis : Betrem & Bradley 1964: 443; Baltazar 1966: 230; Osten 2005b: 40. Paconzitva alecto : Argaman 1996: 196. Sugorpilfa philippinensis : Argaman 1996: 196.

Material examined. Indonesia. South Sulawesi province. 1♀ 3♂, Tompobulu , 12.XI.2020 (local coll. leg.) [ CJBC]; 1♀, Palolo, 4.XII.2017 (local coll. leg.) [ CJBC]. West Kalimantan province. 1♀, Mont Bawang, 10.IX.2014 (local coll. leg.) [ CJBC]. The Philippines. Baatan province. 2♀ 1♂, Mariveles, 10-15.V.2017 (local coll. leg.) [ CJBC]. Cotabato province. 1♀, Alamanda, 8.XII.2018 (local coll. leg.) [ CJBC]; 1♀ 1♂, Arakan, 10.IV.2021 (local coll. leg.) [ CJBC]. North Samar province. 1♀, Lope de Vega , 26.XI.2023 (local coll. leg.) [ CJBC]. South Agusan province . 1♂, San Luis, 10.IV.2018 (local coll. leg.) [ CJBC]. South Davao province. 1♀, Kapatagan, 18.II.2017 (local coll. leg.) [ CJBC]; 1♀, same place, 9.III.2017 (local coll. leg.) [ CJBC] .

Diagnosis. Regiscolia alecto (Smith, 1858) , comb. nov. differs from R. almoraensis ( Gupta & Jonathan, 2003) , comb. nov., R. bidens ( Linnaeus, 1767) , comb. nov., R. maculata ( Drury, 1773) , comb. nov., and R. rubida ( Gribodo, 1893) , comb. nov., in females by having the apical part of scutum with sparse punctures medially or without puctures, thus not forming a continuous band of punctures along the scutellum; the dorso-median area of propodeum distinctly longer than the metanotum; and the basal part of T2 has finer and denser punctures forming a band, the median part being sparsely and coarsely punctate. In contrast, in R. almoraensis , R. bidens , R. maculata , and R. rubida the apical part of scutum has a denser and uninterrupted band of punctures along the scutellum; the dorso-median area of propodeum is shorter, approximately equal to the length of the metanotum; and the basal part of T2 has sparser punctures similar to those of the median part. In males, R. alecto differs by having the area around and between the posterior ocelli with sparse and coarse punctures; and the length of the dorso-median area of propodeum significantly greater than that of the metanotum. In contrast, in R. almoraensis , R. bidens , R. maculata , and R. rubida , the area around and between the posterior ocelli has very denser, tighter, finer, and agglomerated punctures; and the length of the dorso-median area of propodeum is nearly equal to that of the metanotum. In both sexes, the wings of R. alecto are entirely dark. Whereas in R. almoraensis , R. bidens , R. maculata , and R. rubida , they are bicolored, yellowish in the cells and dark elsewhere (in R. almoraensis the wings are almost entirely black).

R. alecto is easily distinguished from R. capitata ( Fabricius, 1804) , comb. nov. in both sexes by having the head with coarse and dense punctures; and the mesosoma and metasoma entirely melanistic. In contrast, in R. capitata the head is almost entirely impunctate with finer and sparser punctures; and the scutellum, metanotum, dorso-median area of propodeum, T1, and T3 are generally marked with yellow.

R. alecto is distinguished from R. azurea ( Christ, 1791) , comb. nov. in female, by having the pronotum with dense, tight, and fine punctures over its entire surface; the transition between the dorso-median and postero-median areas of propodeum forming an angle without a protrusion; and the basal part of T2 with dense and fine punctures forming a continuous band across its entire width. In contrast, in R. azurea , the pronotum has coarser and sparser punctures on the posterior half, showing a large impunctate area anterior to the pronotal excavation; the transition between the dorso-median and postero-median areas of propodeum generally forms a protruding ridge; and the basal part of T2 usually has denser and finer punctures forming a band, but the punctation is interrupted medially. In males, R. alecto differs by having the T1 with dense and fine punctures across its entire surface; and the metasomal pilosity entirely black. Whereas in R. azurea , the basal part T1 has an impunctate area at the level of the tubercle; and the metasomal pilosity is reddish apically.

R. alecto is distinguished from R. fulvifrons ( Saussure, 1855) , comb. nov. and R. splendida ( Saussure, 1858) , comb. nov., by having the mesosoma and metasoma entirely melanistic. Whereas in R. fulvifrons and R. splendida , at least the metasoma is marked with orange-yellow on the T3, and sometimes the mesosoma as well.

Redescription. Female ( Fig. 49 View FIGURE 49 ). Length 32–40 mm.

Head ( Figs 49B, C View FIGURE 49 ). Mandibles short and thickened at the apex. Median mandibular tooth small and prominent, sometimes blunt. Anterior margin of clypeus rounded, without prominent lateral lobes; disk of clypeus not-domed and reticulated apically. Fissura frontalis weak and inconspicuous. Frons with numerous and sparse punctures. Vertex almost impunctate, except behind posterior ocelli with few sparse punctures.

Mesosoma ( Fig. 49D View FIGURE 49 ). Pronotum finely and densely punctate over its entire surface. Tegula with coarse punctures at base and along scutum; with micro-punctures often effaced on rest. Scutum finely and densely punctate basally; more sparsely laterally, except for lateral corners with very dense and fine punctures; largely impunctate medially and apically. Scutellum with fine and dense punctures basally; sparser medially and apically, with distinctly impunctate surfaces. Metanotum finely and densely punctate with a small impunctate central band. Dorso-lateral area of propodeum densely and finely punctate, anteriorly with an impunctate area (mirror). Dorso-median area of propodeum clearly longer than the length of the metanotum; punctures fine and dense over its entire surface. Upper plate of metapleuron impunctate on its lower third, finely and densely punctate on the rest. Anterior margin of marginal cell longer than posterior margin. Forewing with three submarginal cells. Hind tibiae spurs of similar length.

Metasoma ( Fig. 49E View FIGURE 49 ). T1 with a tubercle not depressed in the middle; coarsely and sparsely punctate basally revealing a small impunctate area in its center; very densely and finely punctate laterally and apically. Basal part of T2 densely and finely punctate continuous along its entire width; very sparsely punctate medially; very finely and densely punctate apically. T3 almost entirely impunctate basally and medially; densely and finely punctate apically. T4 to T5 with similar punctation, but the central impunctate area gradually reduced. S1 densely and finely punctate over its entire surface. S2 with strong tubercle; with fine and dense punctures basally; with sparse and coarse punctures medially; with dense and fine punctures on sides apically, sparsely punctate in the middle apically. S3 to S5 with similar punctation.

Coloration ( Figs 49 View FIGURE 49 , 51 View FIGURE 51 ). Head marked with yellow on frons and vertex; ocellar region black. Antennae black. Mesosoma black. Metasoma black. Legs black. Wings entirely dark, with blue/purple or blue/greenish reflections. Body pilosity black. In subspecies regnatrix ( Fig. 50 View FIGURE 50 ) as in the nominotypical subspecies ( Fig. 49 View FIGURE 49 ), except with the apical fringes of T2, sometimes those of T 3 in part and those of T 5 in the middle reddish. The subspecies philippinensis ( Fig. 51 View FIGURE 51 ) is not distinguishable from the nominotypical subspecies.

Male ( Fig. 52 View FIGURE 52 ). Length 25–29 mm.

Head ( Figs 52B, C View FIGURE 52 ). Inner margin of mandible with three distinct tooth (third apical tooth sometimes blunt and barely visible). Disk of clypeus with few shallow and sparse punctures medially, denser and coarser punctures basally and laterally. Fissura frontalis barely visible after the frontal spatium, not reaching the anterior ocellus. Frontal cross-furrow barely visible, its extension reaching the upper lobe of the eye. Frontal spatium with dense, tight and fine punctures. Anterior ocelli depressed, larger than posterior ocelli. Frons with dense and coarse punctures, except in front of anterior ocellus with an impunctate area. Vertex behind the ocelli with sparse and fine punctures, dense punctures near the occipital carina.

Mesosoma ( Fig. 52D View FIGURE 52 ). Pronotum with dense, tight and fine punctures over its entire surface, inter-points spaces almost coalescent. Tegula with few coarse punctures anteriorly, with shallow and dense micropunctures on the rest. Scutum with fine and dense punctures, more sparser apically. Scutellum with fine and dense punctures basally, sparser and coarser medially and mostly impunctate apically. Metanotum with fine and dense punctures laterally, impunctate line in the middle. Dorso-lateral area of propodeum with a large impunctate area (mirror); with fine, dense and deep punctures; in front of mirror, with a patch of very fine and dense punctures. Dorso-median area of propodeum with coarse and dense punctures over its entire surface. Anterior margin of the marginal cell longer than posterior margin. Forewing with three submarginal cells.

Metasoma ( Fig. 52E View FIGURE 52 ). T1 with a strong tubercle; very dense and fine punctures laterally and apically; more coarsely and sparsely punctate basally at the level of tubercle. T2 with fine and dense punctures; more denser and finer punctures basally and apically, at these levels pilosity forming a large band. T3 largely impunctate medially, with very dense and fine punctures apically, less dense and sparse basally. T4-T6 similarly punctate, but the central impunctate area smaller. S1 raised in the middle, with dense punctures. S2 with dense and fine punctures basally, sparser laterally, mostly impunctate medially and apically. S3 with very sparse punctures medially, more denser laterally. S4-S6 similarly punctate.

Coloration ( Figs 52 View FIGURE 52 , 53 View FIGURE 53 ). Frons, vertex and tempora yellow-orange, black on the rest. Clypeus black in philippinensis ( Fig. 53 View FIGURE 53 ), yellow-orange in nominal subspecies ( Fig. 52 View FIGURE 52 ). Mesosoma and metasoma black. Pilosity black. The male of subspecies regnatrix is unknown.

Genitalia. See Fig. 31A View FIGURE 31 .

Distribution. Indonesia ( North Maluku, South Sulawesi, West Kalimantan), The Philippines (Baatan, Batangas, Cotabato, Laguna, North Samar, South Agusan, South Davao) ( Rohwer 1921; Micha 1927; Betrem 1928 1941; Betrem & Bradley 1964) ( Fig. 54 View FIGURE 54 ). Betrem (1928, 1941) mentions the locality of Malacca (a city in Malaysia) for two female specimens of Scolia alecto . These identifications appear doubtful, these specimens mostly belong to R. azurea (see remarks of R. azurea ).

Biology. Unknown.

Remarks. To date, two subspecies have been recognized ( Betrem & Bradley 1964; Osten 2005b): ssp. alecto alecto (Smith, 1858) from Sulawesi and ssp. regnatrix Betrem & Bradley, 1964 from Borneo, known only from the female. R. alecto regnatrix differs from the nominate subspecies ( Fig. 49 View FIGURE 49 ) only in female, with all-black pilosity, and reddish apical pilosity on T2, T5 and pygidium (sometimes also on T1 and/or T3) ( Fig. 50 View FIGURE 50 ). We were able to examine two females whose coloration conforms to the original description, and this taxon appears to be restricted to Borneo.

Examination of numerous specimens of Scolia ( Triscolia) philippinensis Rohwer, 1921 , syn. nov. shows that this taxon is synonym with Scolia alecto Smith, 1858 . The males of S. ( T.) philippinensis differ only from the males of R. alecto alecto by the clypeus entirely black ( Fig. 53 View FIGURE 53 ), whereas in R. alecto alecto it is almost entirely orange ( Fig. 52 View FIGURE 52 ). There are no morphological or coloration differences in females ( Figs 49 View FIGURE 49 , 51 View FIGURE 51 ), contrary to what is stated by Betrem (1928). S. ( T.) philippinensis must now be considered as a subspecies of R. alecto . Regiscolia alecto philippinensis ( Rohwer, 1921) , stat. nov. is known only from The Philippines.

Key to potential subspecies of Regiscolia alecto

Females

1. Metasoma with black pilosity ( Figs 49 View FIGURE 49 , 51 View FIGURE 51 ). Indonesia ( Sulawesi) and The Philippines............................... 2

- Metasoma with black pilosity mixed with reddish pilosity on T2 apically and pygidium ( Fig. 50 View FIGURE 50 ). Indonesia (Borneo).......................................................................................... ssp. regnatrix (Smith)

2. The Philippines ( Fig. 51 View FIGURE 51 ................................................. ssp. philippinensis (Rohwer) , stat. nov.

- Indonesia ( Sulawesi) ( Fig. 49 View FIGURE 49 )............................................................. ssp. alecto (Smith)

Males (unknown in ssp. regnatrix )

1. Clypeus almost entirely orange ( Fig. 52 View FIGURE 52 ). Indonesia............................................ ssp. alecto (Smith)

- Clypeus black ( Fig. 53 View FIGURE 53 ). The Philippines.................................... ssp. philippinensis (Rohwer) , stat. nov.

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Hymenoptera

Family

Scoliidae

Genus

Regiscolia

Loc

Regiscolia alecto (Smith, 1858)

Castagnet, Jean-Baptiste & Cabon, Flavien 2025
2025
Loc

Scolia alecto

Betrem, J. G. 1928: 237
Smith, F. 1858: 10
1858
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