Sunday, June 16, 2024

[Entomology • 2024] Spinanycta alabamensis • A New Genus and Species of nicoletiid Silverfish (Zygentoma: Nicoletiidae) from Caves of northern Alabama, USA


Spinanycta alabamensis Espinasa, Gutierrez & Niemiller, 

in Espinasa,  Gutierrez, Hinkle et Niemiller, 2024. 

Abstract
A new genus and species of troglobiotic nicoletiid (Insecta, Zygentoma, Nicoletiidae) is described from northern Alabama, USA. The type species was collected from three caves in the Highland Rim section of the Interior Low Plateau physiographic province on the northern side of the Tennessee River Valley. Morphological and genetic analysis using the mitochondrial 16S rRNA locus show that Spinanycta alabamensis sp. nov. is quite distinct from related nicoletiids in North America. The species differs from members of other genera by its urosternum I, which in males is modified with a central pointy extension. The new species significantly extends the distribution of cave-dwelling members of the family into the southeastern United States and suggests that additional nicoletiid diversity remains to be discovered from karst regions of the eastern United States.

Keywords: Insect, Interior Low Plateau, subterranean, Thysanura, troglobite, troglobiont

Spinanycta alabamensis sp. nov.
A male holotype (left) and female paratype (right) B–L male holotype B, C pedicellus D head E macrochaetae by insertion of antennae F labium G last article of labial palp H sensilla of maxillary palp I maxilla J apex of lacinia K conules of galea L sensilla of maxillary palp.

Spinanycta alabamensis sp. nov. female in life, observed on 13 September 2023 at the type locality Bobcat Cave, Madison County, Alabama, USA.
Photograph by Eric C. Maxwell.

Class Insecta Linnaeus, 1758

Order Zygentoma Börner, 1904
Suborder Neozygentoma Engel, 2006
Infraorder Euzygentoma Grimaldi & Engel, 2005

Family Nicoletiidae Escherich, 1905

 Spinanycta Espinasa, Gutierrez & Niemiller, gen. nov. 

 Spinanycta alabamensis Espinasa, Gutierrez & Niemiller, sp. nov.

Diagnosis: An American nicoletiid with Urosterna II–VII subdivided into two coxites and one sternite. Urosterna I, VIII and IX of male entire. Coxites on segments II–IX with styli. Urosternum I of males modified with a central pointy extension. Urosternum VIII of male flat posteriorly, without emarginations or projections in between the styli of this segment. Paramera with a distal semi-eversible vesicle and short chaetae, their length being about 1/4 the width of the paramera. Subgenital plate of females subtriangular. Tergum X with one distinct macrochaetae on posterior angles. Cercus of male with sensory pegs (spines) and appendix dorsalis without sensory pegs.

Etymology: Spinanycta. From spina = Greek for spine. It references the diagnostic spine in urosterum I, and nycta = Greek for night. It references in Greek mythology the occupation of caves by Nyx, the primordial goddess of night.

Distribution: This genus is known from just three cave systems on the north side of the Tennessee River Valley in southern Madison and southeastern Limestone counties, Alabama, within the Highland Rim section of the Interior Low Plateau physiographic province (Fig. 1).


 Luis Espinasa, Abrianna Gutierrez, Amata Hinkle and Matthew L. Niemiller. 2024. A New Genus and Species of nicoletiid Silverfish (Insecta, Zygentoma, Nicoletiidae) from Caves of northern Alabama, USA. Subterranean Biology. 49: 1-17. DOI: 10.3897/subtbiol.49.119986