First report of Dryinus garcetei Olmi, 2012 (Hymenoptera, Dryinidae) in the Northeast region of Brazil

. The present study reports the first record of Dryinus garcetei Olmi, 2012 (Hymenoptera, Dryinidae) for Northeast Brazil. This research is very relevant given the scarcity of data regarding the Dryinidae family and the Dryinus Latreille, 1804 genus for this region. Furthermore, illustrations and an updated geographic distribution map of D. garcetei are presented.

In Brazil, knowledge about pincer wasps is still incipient for most of the country.The North, Central-West and Northeast regions are the least covered by studies on Dryinidae (Coelho et al. 2011;Olmi & Virla 2014;Martins 2022;2023;2024).These regions are characterized by the lack of sampling effort aimed at collecting these insects and the lack of specialists of this group working in these regions (Olmi & Virla 2014;Martins 2022;2023;2024).In the Northeast region, only three recent studies present data on dryinids fauna (Martins 2022;2023;Santos et al. 2024).
In this context, Bahia contains areas such as the Chapada Diamantina region, which, in addition to being an important agricultural hub, houses great biodiversity and different types of ecosystems, due to the presence of biomes such as the Cerrado and Caatinga (Fernandes et al. 2020;Castro et al. 2023).Thus, the present study aimed to present the unpublished record of Dryinus garcetei Olmi, 2012 (Dryinidae, Hymenoptera) for the Northeast region of the country and the state of Bahia.
The material was collected in Chapada Diamantina, in the region that comprises the agricultural hub Mucugê-Ibicoara (13°09'10" S, 41°28'40" W), state of Bahia, Brazil.For sampling, Pan Traps were used at 40 sampling points.Each point was sampled bimonthly during eight months of the year 2011.Collections were carried out using three Pan Traps of three different colors (blue with ultraviolet, yellow with ultraviolet and white) at each point.
The material was sent to the Laboratório de Bionomia, Biogeografia e Sistemática de Insetos da Universidade Federal da Bahia (BIOSIS/ UFBA) and deposited under the tomb number MHNBA-Hymeno 16489, in the entomological collection of the Zoology sector of Museu de História Natural da Bahia (MHNBA/UFBA).Taxonomic identification was carried out based on the available literature (Olmi 2012;Olmi & Virla 2014) and terminology to for wing venation by (Martins & Melo 2024), and compared with type specimen.Photography of studied specimen were carried out with the aid of a stereomicroscope, send to the co-author and confirmed by expert on this group (A.L. Martins).
The geographic distribution map of the species (Fig. 1A) was made using the geographic coordinates available in the scientific literature (Olmi 2012;Olmi & Virla 2014;Martins et al. 2015a), added to those obtained in this study.
Only one specimen of D. garcetei (Fig. 1B) was collected in a yellow Pan Trap, in August 2011.According to Olmi & Virla (2014) and Martins et al. (2015a), D. garcetei (Fig. 1B) is morphologically characterized by presenting the following characters: black head, except for dark brown mandibles and antennae and tenth whitish flagellomere; mesosoma black; fore wing venation with two dark transversal bands and metasoma predominantly black, except by dark brown apex; head with reticulated-rough sculpture; posterior ocelli almost reaching the occipital carina; incomplete occipital carina, restricted only at the vertex; pronotum with longitudinal and transverse carinae around the disc; pronotal lobe not reaching the tegula; mesoscutum, scutellum and reticulate-rough propodeum; propodeum with two longitudinal carinae delimiting the median region with hairiness; and 2r-rs short than 3Rs&4Rs; enlarged claw with a subapical tooth and a row of 12 lamellae; 5th protarsomere with two rows of 27 lamellae; and tibial spurs in a 1-1-2 ratio.
Dryinus garcetei, has previously only been recorded to occur in Mexico, Paraguay and Brazil [state of São Paulo -located in the southeast region of the country] (Martins et al. 2015a;Olmi & Virla 2014).This is, therefore, the first record of this species occurring in the Northeast region of Brazil specifically for the state of Bahia (Fig. 1A).
The results presented in this study, therefore, consist of expanding the geographic distribution of D. garcetei for the Cerrado biome in Brazil, since this species was only recorded for the Brazilian Atlantic Forest, thus reducing the Wallacean deficit for this group (Whittaker et al. 2005;Martins et al. 2015aMartins et al. , 2015b;;Ramos et al. 2022;Vergara-Asenjo et al. 2023;Marambaia et al. 2023).This is corroborated by several studies that point out the fact that biomes characteristic of the Northeast region (especially the Caatinga and the Cerrado) are extremely rich in biodiversity, however, they are still poorly sampled (Santos et al. 2011;Oliveira et al. 2016;Martins 2022;Santos et al. 2024).
Such a deficit can make conservation strategies for these species unfeasible, preventing/making it impossible to develop techniques for using these insects as biological control tools for agricultural pests (Lemes et al. 2011;Regos et al. 2019;Melo-Merino et al. 2020).
In this case, the unprecedented record of D. garcetei for the Northeast region of Brazil, along with other work carried out by our research group (e.g., Lopes et al. 2018;Ramos et al. 2018;2021;2022;Marambaia et al. 2023) highlights just how much the Hymenoptera fauna is still unknown in this Brazilian region.Therefore, encouraging research in these areas, not only on Dryinidae, but also involving different taxonomic groups (especially those that do not have specialists working in the area) is essential for the development of more assertive public policies with regard to conservation, management and sustainable use of biodiversity.