Two new species of Ageniella Banks, 1912 (Hymenoptera: Pompilidae) from Brazil and updated keys

Abstract. Ageniella Banks, 1912 is a paraphyletic group exclusive to the Nearctic and Neotropical regions. The genus has a remarkable morphological diversity among species and strong sexual dimorphism, hampering taxonomic studies of it. Herein, we add two new species to the Neotropical fauna of Ageniella: A. caerulea sp. nov. belonging to the subgenus Ameragenia and A. ruschi sp. nov. belonging to the subgenus Priophanes; both species are described and illustrated. A brief discussion of subgeneric characters and an updated taxonomic key to the species of Ageniella known from Brazil are provided.

Ageniella is exclusive to the New World (Waichert et al. 2018). It was first described by Banks (1912) to house 17 species; currently there are about 200 names attributed to Ageniella, many of which are synonymous (Waichert et al. 2018). Ageniella is a paraphyletic genus (Shimizu et al. 2010;Waichert et al. 2019) that shows considerable structural diversity among species, including strong sexual dimorphism in some species (Evans 1997).
Currently, Ageniella has eight recognized subgenera, namely, Ageniella, Alasagenia Banks, 1944, Ameragenia Banks, 1945, Cyrtagenia Evans, 1973, Leucophrus Townes, 1951, Nemagenia Banks, 1944, Neotumagenia Fernández, 1998, and Priophanes Banks, 1944(Waichert et al. 2018. Of these, Alasagenia, Cyrtagenia and Neotumagenia are endemic to the Neotropical region, which is the most diverse and least studied area of distribution of the genus. Waichert et al. (2018) revised the names occurring in Brazil, reporting 40 species of Ageniella and proposing a key to the subgenera and species of Ageniella. Here, we describe two new species of Ageniella from Brazil. The keys for Priophanes and Ameragenia are updated and photographs of the species are provided.

Abbreviations for morphological terms
The species were described and named according to the International Zoological Nomenclature Code, prepared by the International Commission on Zoological Nomenclature (1999). The specimens had their external and internal structures (male genitalia) described according to the terms proposed by Wasbauer & Kimsey (1985). Wing venation terminology follows Goulet & Huber (1993). DF = facial distance LA3 = length of the third segment of the antenna LC = maximum length of the clypeus MID = maximum interocular distance OLO = ocelocular length PDT = transfacial distance POL = post-cellular length UID = upper interocular distance WA3 = width of antennomere 3 WC = width of the clypeus, measured from the widest points 1M = first discal cell 2M = second discal cell 1Rs = first submarginal cell 2R1 = marginal cell 2Rs = second submarginal cell 3Rs = third submarginal cell Taxonomic characters related to the male genitalia and hypopygium were examined after dissection. Dissected genitalia and hypopygia were soaked in a 10% KOH solution for diaphanization of tissues and transferred into a microvial filled with glycerin for preservation. The microvial was pinned with the specimen for morphological analyses and illustration.
Type specimens were photographed using a Leica Z16 APO stereo microscope fitted with a camera adaptor coupled to a Leica DFC 295 video camera (Leica Microsystems, Switzerland, Germany). The Leica Application Suite ver. 3.6.0 software and Microsystems by Leica Limited (LAS) were used. Illumination was provided by a scaleable and modular LED illumination dome, as described in Kawada & Buffington (2016). Helicon Focus (ver. 4.2.9; HeliconSoft, Dominica) combined stacks into a single image. The male genitalia were photographed using a Euromex microscope (Euromex Microscopen, The Netherlands) fitted with a HD-mini camera. Individual focal photographs were focus stacked in the Focus stacking online (https://focusstackingonline.com/) software using the Beta alignment method.

Results
We recognize two species that are reported here for the first time and included in the subgenera Ameragenia Banks and Priophanes Banks, as detailed below.
Class Insecta Linnaeus, 1758 Order Hymenoptera Linnaeus, 1758 Family Pompilidae Latreille, 1804 Genus Ageniella Banks, 1912 Subgenus Ameragenia Banks, 1945Ameragenia Banks, 1946 1A); the antenna is castaneous; the clypeus is trapezoidal, blue with greenish reflection; and the forewing is hyaline with two darkened bands. In females, the wing cells are darker than in males; the antennae, tibiae and fore tarsi are paler in males than in females ( Fig. 1A, C).

Etymology
The specific epithet is Latin and refers to the blue color that stands out from that of the other spider wasps known from the Amazonian area. Coloration (Fig. 1). Head blue with purple-greenish reflections; antenna dark castaneous; clypeus blue with greenish reflections, apical margin dark castaneous; setae silver; mandible dark castaneous with greenish reflections; maxillary setae castaneous; mesosoma blue with purple-greenish reflections; metasoma dark castaneous with blue-greenish reflections; wings hyaline; forewing with two darkened bands: inner band covering vein M, basal portion of cells R, 2Cu, distal portion of vein 1Cu, and outer band covering cells 2R1, 3Rs, 2Rs, distal portion of 2M; forewing apex slightly darkened; veins castaneous.
MesosoMa (Fig. 1A, C). Punctation inconspicuous. Pubescence sparse, thin; propodeum with long setae. Pronotum not elongated, width about 2.6 × its length; pronotal collar short. Propodeum with slope slightly curved in profile. Forewing long, maximum width 0.35 × its length; 2R1 3.0 × as long as its distance to apex; 3Rs 1.3 × as long as 2Rs; 2Rs cell 2.0 × as wide as long; 3Rs somewhat triangular; second recurrent vein curved, meeting 2Rs at 2.0 × distance from base to apex of cell. Fore, mid and hind tibiae with thick, short spines; hind tibiae with spines arranged in rows.

Remarks
The allotype has lost the antennal segment four onwards and the last three terga of the metasoma. This species has a unique blue-greenish color among the species of Ageniella. Usually the species of Ageniella have dark blue reflections, but they are rarely completely metallic blue and with greenish reflections as seen in this species. Ageniella dominguensis (Banks, 1944) has a blue color similar to that of A. caerulea sp. nov., but it differs from the latter by having a large body size, long setae covering the integument, and wings darkened without bands. Moreover, A. dominguensis is endemic to the Dominican Republic.
Subgenus Priophanes Banks, 1944Priophanes Banks, 1944 Diagnosis Ageniella ruschi sp. nov. is unique among the species of Ageniella by having golden scale-like setae basally and above the clypeus and the wings darkened with the apex white; the integument is dark castaneous (Fig. 3); and the clypeus is trapezoidal with the median apical margin polished and projected. The male of this species remains unknown.

Discussion
The present study adds two species to Ageniella, for the subgenera Ameragenia and Priophanes. The recognized species were included in the identification keys provided by Waichert et al. (2018), which has been improved and updated. Waichert et al. (2018) included both, A. (Ameragenia) rustica (Fabricius) and A. (Ameragenia) zeteki (Banks), in the key for A. (Ameragenia) but listed them as A. (Alasagenia) in table 1. The authors discuss the presence of serrate legs and long-erect setae covering the body of these specimens, characters that overlap descriptions of subgenera Priophanes and Ameragenia, respectively, and also fit within species of A. (Alasagenia). However, Waichert et al. (2018) did not formally transfer the species to A. (Alasagenia) and we keep these two species as A. (Ameragenia) in the taxonomic key. Ageniella (Ameragenia) rustica and A. (Ameragenia) zeteki are probably a distinct lineage within Ageniella, but further data, such as nucleotide sequences, are needed for nomenclatural actions.
Although Ageniella is unquestionably paraphyletic (Shimizu et al. 2010;Waichert et al. 2015), we describe and place each species in a current subgenus for future studies and taxonomic delimitation. Ageniella caerulea sp. nov. is assigned to the subgenus Ameragenia, because it has the propodeum and the pronotum rounded in dorsal and profile views. The dorsal face of the hind tibia is spiny, but the spines are not similar to scales and the forewing is hyaline with dark bands. These features resemble those of other Neotropical species classified as A. (Ameragenia), such as A. fabricii (Banks).
Ageniella ruschi sp. nov. is assigned to the subgenus Priophanes due to the fact that it has a small to medium body size. The female has the hind tibia with scale-like spines, as known females in the subgenus. This species, however, differs from other species of the genus because of its darkened forewing with white tips.
Finally, this study represents a significant contribution to the systematics of a diverse group in a highly threatened biodiversity.