Archaeopodagrion oelmannae, Bota-Sierra, 2025

Archaeopodagrion oelmannae sp. nov.

Examined material ( 1♂): Holotype. COLOMBIA: Antioquia Department, Los Magnolios Reserve , Corcovado Township , Yarumal Municipality, elev. 1263 m, N 7.065918° W 75.410252°, at the forest edge near a stream, 30.iv.2023, Leg. C. Bota & J. Alzate. Deposited in the Colección Entomológica de la Universidad de Antioquia CEUA (Medellín), code: CEUA 144643 . GoogleMaps

Etymology: Yvonne Oelmann is a German geoecologist whose research focuses on biodiversity. She has worked on projects in Europe ( Germany, Estonia, Latvia, Lithuania), Central and South America ( Argentina, Chile, Ecuador, Panama), and China. She is using isotope analysis to research the migration of dragonfly species in Europe. Her husband and dragonfly expert Christoph Willigalla is gifting her a dragonfly species named after her to celebrate their silver wedding anniversary.

Description. Two male individuals of the species have been observed ( Figures 1a–b View FIGURE 1 ), but unfortunately one of them was not collected. The males perch on twigs and leaves with the wings wide open.

Male holotype

Head ( Figures 1a–b View FIGURE 1 , 2a–b View FIGURE 2 ). Black except: labrum cream colored; labium, base of mandible, gena, clypeus except carina separating ante- and post-clypeus, antennal socket, and apex of first antennomere, bluish white. Posterior part of frons sculptured, giving a green iridescent color. Frons rounded.

Thorax. Prothorax bluish white except medial portion of pronotum ( Figures 1a–b View FIGURE 1 ). Posterior lobe of pronotum prolonged laterally into two pairs of processes ( Figures 2b–c View FIGURE 2 ): one on dorsoposterior margin and the other on laterobasal margin; dorsoposterior processes long and sinuously curved dorsoposteriorly, their tips blunt, pointing dorsolaterally ( Figure 2c View FIGURE 2 ), and extending over ⅓ of the pterothorax ( Figures 2b–c View FIGURE 2 ); laterobasal processes shorter and thinner, around a fifth of the length of the dorsoposterior processes, extending posteroventrally and with tips recurved ( Figures 2b–c View FIGURE 2 ). Pterothorax bluish white except ( Figures1a–b View FIGURE 1 ): middorsal stripe, mesepimeron, metepisternal stripe and a small stripe on the posterior fourth of metepimeron which are dark brown ( Figure 2b View FIGURE 2 ). Legs. Coxae yellowish. Internal surface of femora bluish and internal surface of tibiae yellowish, external surface of legs brown ( Figures 1a–b View FIGURE 1 ). Eleven spurs on external side of right metafemur and nine on left metafemur, as long as the space between them or longer, gradually increasing in size toward apex. Nine spurs on anterior side of metatibia, longer than space between them, gradually decreasing in size toward apex. Ten scale-like spurs on apex of protibia. Tarsal claws with developed supplementary tooth. Left proleg underdeveloped. Wings. hyaline. Pt dark brown surmounting one and a half to two cells, ratio between distal and proximal length about 1:1. Px right 20/left 19 in FW, Px right 19/left 18 in HW.

Abdomen. Black except pale areas as follows: distal transverse stripe on S1, S7–9; incomplete apical rings on S3–7; sides of S1–2; a ventrolateral stripe on apical ¾ on S3, apical ¼ on S4–6, and S7–8 ( Figure 1a–b View FIGURE 1 ). Genital ligula. with long paired coiled flagella on distal segment, similar to the other species of genus. Anal appendages. Cercus in lateral view curved upwards, longer than S9+S10, with an internal rounded process at apical third ( Figures 3a–c View FIGURE 3 ). Paraproct as long as ¾ of cercus, apex pointed, curving upwards, with a middorsal process bearing two pointed little teeth ( Figures 3a–c View FIGURE 3 ). Measurements (mm): FW 26; HW 25; abdomen 33; total length 41.

Diagnosis. Archaeopodagrion oelmannae can be easily distinguished by the unique shape of its pronotum ( Figures 2b–c View FIGURE 2 ) and caudal appendages ( Figures 3a–c View FIGURE 3 ). The shape of posterior lobe of pronotum is very elaborated in the genus Archaeopodagrion , and A. oelmannae has probably the most exaggerated of them, with two pairs of processes and the dorsoposterior ones extending over ⅓ of the pterothorax. A. mayi has the most similar shape of pronotum sharing the two pairs of processes, but the dorsal pair reaches ¼ of the length of pterothorax. In lateral view, the most distal point of the body in A. oelmannae is represented by cercus tip; this is only shared with A. fernandoi , since the paraproct tip is the most distal point in all other known species. Finally, the paraproct of A. oelmannae with a midorsal process bearing two pointed teeth is unique within the genus.

Taxonomic key. Amaya et al. (2021) presented a taxonomic key for the genus based on the shape of anal appendages. Here a key for males of the genus based on the posterior lobe of pronotum is given. When using it, it is advisable to consult the illustrations of prothoracic lobes provided by Kennedy (1939, 1946), Tennessen & Johnson (2010), Bota-Sierra (2017), and Amaya-Vallejo et al. (2021). As all known species have restricted geographic distributions ( Figure 4 View FIGURE 4 ), the provenance of the specimen is helpful for species identification.

1. Posterior lobe of pronotum with four narrow processes, the laterobasal ones short compared with the dorsal processes ( Figures 2b–c View FIGURE 2 )............................................................................................... 2

1 -Posterior lobe of pronotum with flap-like processes.......................................................... 4

2. Dorsal processes of pronotum longer and projected parallel to the pterothorax, extending over it ( Figure 2b–c View FIGURE 2 )........... 3

2 -Dorsal processes of pronotum shorter and perpendicular to pterothorax, not extending over it (Colombian Western Andes)............................................................................... Archaeopodagrion fernandoi

3. Long dorsal processes of pronotum extending over ⅓ of pterothorax ( Figure 2b View FIGURE 2 ); tip of pronotum laterobasal processes recurved ( Figure 2c View FIGURE 2 ) (Colombian Central Andes)............................................. Archaeopodagrion oelmannae

3 -Long dorsal processes of pronotum extending over 1/4 of pterothorax; tip of laterobasal of pronotum processes straight (Ecuadorian Western Andes).......................................................... Archaeopodagrion mayi

4. Flap-like process on posterior lobe of pronotum with laterobasal tips curved distad (Colombian Western Andes)...................................................................................... Archaeopodagrion recurvatum

4 -Flap-like process on posterior lobe of pronotum without laterobasal tips curved distad.............................. 5

5. Flap-like process on posterior lobe of pronotum internal border curved proximad (Ecuadorian Eastern Andes)............................................................................................ Arhaeopodagrion bicorne

5 -Flap-like process on posterior lobe of pronotum internal border not curved proximad ( Ecuador)...................... 6

6. Flap-like process on posterior lobe of pronotum projected distad over pterothorax with distal edge bilobated (Ecuadorian Eastern Andes)................................................................ Archaeopodagrion bilobatum View in CoL

6 -Flap-like process on posterior lobe of pronotum projected distad over pterothorax with distal edge slightly sinuous (Ecuadorian Eastern Andes)................................................................. Archaeopodagrion armatum View in CoL

Habitat and Conservation. This species was observed near small streams in mountain forests between 1260 and 1500 m asl. The known habitat of the species is inside a small private reserve, which protects around 65 hectares of suitable habitat. Inside the reserve the size of the population is small, and more research is needed to establish its conservation status. However, there are strong agricultural pressures in the region, which are degrading and reducing the habitat of the species outside the reserve, so it is likely that the species is endangered.