Plusiocampa ( Stygiocampa ) petrovi Sendra & Stoev, 2025

Sendra, Alberto, Stoev, Pavel & Selfa, Jesús, 2025, Cave-adapted Plusiocampinae (Diplura, Campodeidae) from the eastern part of the Balkan Peninsula, Deutsche Entomologische Zeitschrift 72 (2), pp. 317-340 : 317-340

publication ID	https://doi.org/10.3897/dez.72.162647
publication LSID	lsid:zoobank.org:pub:698183AA-967C-4646-A71E-2A02892922B5
persistent identifier	https://treatment.plazi.org/id/CD221991-3EEC-5EB3-8D70-7C0C17C461E7
treatment provided by	Deutsche Entomologische Zeitschrift by Pensoft
scientific name	Plusiocampa ( Stygiocampa ) petrovi Sendra & Stoev
status	sp. nov.

Treatment

Plusiocampa ( Stygiocampa) petrovi Sendra & Stoev sp. nov.

Figs 18 View Figure 18 , 19 View Figure 19 , 20 View Figure 20 , 21 View Figure 21

Etymology.

We name this species after the late colleague and friend Boyan Petrov, a zoologist at the National Museum of Natural History in Sofia, who collected most of the material studied in this publication. The specific epithet is a noun in the genitive case.

Material examined.

Holotype • female deposited in the Natural History Museum of Sofia, Non-insect Invertebrates – Id. 10839 NMNHS. Bulgaria: Vrachanska Planina Mts.: Vrachanski Balkan Natural Park , Vratsa District, Village Pavolche, Cave Pukoya, 750 m alt., 43.16261 ° N, 23.58883 ° E, clay, 03 Jul. 2010, leg. S. Goranov leg. GoogleMaps

Description.

Body. Body length 5.8 mm female holotype. Epicuticle smooth under optical microscope (Fig. 21 a View Figure 21 ); slender body with barbed clothing setae along distal two-thirds of each seta.

Head. Antennae with 41 antennomeres in one completed and intact antenna; antennae, 7 mm long, are approximately ~ 1.2 times longer than the body’s length, with medial antennomeres almost four times longer than wide and apical antennomere three times longer than wide. Cupuliform organ occupying 1 / 9 of total length in the last antennomere has about eight complex olfactory chemoreceptors. Distal and central antennomeres have four to five untidy whorls of smooth macrosetae and scattered smooth setae, in addition to a single distal whorl of 18‒20 long gouge sensilla (35-40 µm long) and up to two very short coniform sensilla 10-12 µm long. Proximal antennomeres with typical trichobothria, plus a small coniform sensillum on the third antennomere in ventral position. Frontal process has non protrusion with clothing setae and a couple of smooth long macrosetae, slightly longer than the three-insertion line macrosetae, with length ratios of a / i / p / x are 21 / 25 / 19 / 19, respectively, in the holotype (Fig. 18 a View Figure 18 ). Labial palps are suboval with small latero-external sensillum, two guard setae, up to six setae on anterior border, and up to 95 neuroglandular setae in the holotype.

Thorax. Thoracic macrosetae distribution (Fig. 19 a View Figure 19 ): pronotum with 1 + 1 ma, 1 + 1 la 3, 1 + 1 lp 1 macrosetae; mesonotum with 1 + 1 ma macrosetae; metanotum without macrosetae. All macrosetae relatively thin, long, and with thin barbs along the basal half to two-thirds of their length; thin marginal setae are also thin, barbed, and double the length of the clothing setae. Legs elongated, and the metathoracic legs overpass 1 / 3 of their length at the end of the abdomen. Tibia longer than the femur or tarsus; coxa / trochanter / femur / tibia / tarsus plus claws: 0.18 / 0.1 / 1.05 / 1.15 / 0.5 mm. Femora I – III with no dorsal macrosetae, and no ventral macrosetae on tibia I-III. Calcars have small thin barbs all over, pubescence type. Two ventral rows of barbed setae on the medial portion of the tarsus; end part of the tarsus with two dorsal smooth long setae plus two ventral long barbed setae. Claws unequal in size, that is, the posterior claw longer than the anterior claw (1.3‒1.4: ratio posterior / anterior). Claws with large lateral crests well developed in posterior claw with a large backward overhang. Pretarsus with similar, long, smooth and setiform lateral processes (Fig. 18 b View Figure 18 ).

Abdomen. Distribution of abdominal macrosetae on tergites: 1 + 1 post 5 short macrosetae on VI, 2 + 2 post 4, 5 on VII, 5 + 5 post on VIII; and 8 + 9 post on IX abdominal segment (fig. 22 b). All tergal abdominal macrosetae long and well-differentiated with thin barbs along their length. Urosternite I with 8 + 8 well-barbed macrosetae (Fig. 20 View Figure 20 ); urosternites II to VII with 5 + 5 macrosetae; urosternite VIII with 2 + 2 macrosetae; long and well-barbed urosternal macrosetae. Stylus with an apical, subapical, and ventromedial seta completely covered with thin barbs all around except at the ending part; apical seta shorter than the others. One apparently intact cercus respectively 1.1 times the body length; divided basal article followed by seven primary articles. Length of the cerci increases from proximal to distal articles (basal: five secondary articles 0.36 mm; 0.19 mm; 0.25 mm; 0.28 mm; 0.30 mm; and seven primary articles 0.33 mm; 0.38 mm; 0.40 mm; 0.40 mm; 0.55 mm; 0.90 mm; 1 mm; 0.90 mm). Each article with a variable number of untidy whorls of macrosetae with short, thin barbs on three / fourth of the distal part and some smooth setae. All primary articles with a distal whorl of longer covered with barbs macrosetae and a more distal whorl of short thin barbed setae.

Secondary sex characters. Female urosternite I with large coniform appendages, bearing each up to 30 glandular a 1 setae in a distal field (Fig. 20 View Figure 20 ). Male unknown.

Taxonomic position.

With the addition of Plusiocampa ( Stygiocampa) petrovi sp. nov., the number of species in the subgenus Stygiocampa Silvestri, 1934 , increases to nine. All are characterized by the absence of notal and urotergal macrosetae, while several species exhibit additional urosternal macrosetae: Plusiocampa ( Stygiocampa) nivea ( Joseph, 1882) , Plusiocampa ( Stygiocampa) remyi Condé, 1947 , Plusiocampa ( Stygiocampa) dalmatica Condé, 1959 , Plusiocampa ( Stygiocampa) christiani Condé & Bareth, 1996 , and Plusiocampa ( Stygiocampa) barethae Sendra & Rađa, 2021 ( Joseph 1882; Condé 1947, 1959; Condé and Bareth 1996; Sendra et al. 2020 b, 2021 b). Among the Stygiocampa species, P. ( S.) bureschi , P. ( S.) christiani , and P. ( S.) petrovi sp. nov. share a pronounced reduction in the number of both notal and urotergal macrosetae. Nevertheless, these species exhibit clear differences, such as the number of macrosetae on the pronotum (1 + 1 ma, 2 + 2-3 + 3 la, 1 + 1 lp in P. ( S.) christiani ; 1 + 1 ma, 2 + 2 la, 2 + 2 lp in P. ( S.) bureschi and 1 + 1 ma, 1 + 1 la, 1 + 1 lp in P. ( S.) petrovi sp. n.) and the number of post macrosetae on the seventh urotergite (0-1 + 1 post in P. ( S.) christiani ; 2 + 2 post in P. ( S.) bureschi and P. ( S.) petrovi sp. nov.). On the other hand, P. ( S.) petrovi sp. nov. has more unequal claws (with a 1.3–1.4: ratio posterior / anterior) than its geographically closest congener, P. ( S.) bureschi (with 1.1: ratio posterior / anterior).

Habitat and distribution.

Pukoya Cave is located in the Krushovitsa area near the village of Pavolche, Vratsa region, within the Vrachanski Balkan Nature Park. The cave is 48 meters long and 178 meters deep. It begins with a short, horizontal gallery, followed by two consecutive shafts; the second of these is approximately 15 meters deep. After that, the cave develops vertically. The middle sections are narrow, requiring ropes to reach the bottom, where water is present (Fig. 21 View Figure 21 ).

In Beron’s (2015) comprehensive monograph on Bulgaria’s cave fauna, no organisms were reported from this cave. Plusiocampa ( Stygiocampa) petrovi sp. nov. is the first species recorded in it. Notably, this new species was found in an area where another representative of the subgenus Stygiocampa , P. bureschi , is also present. The latter was recorded here from caves near the village of Chelopек (about 3 km in a straight line from Pavolche) and Cherepish railway station (approximately 6 km in a straight line).