Pages

Tuesday, 10 June 2025

Nocticola vagus: A new species of parthenogenetic Nocticolid Cockroach from Florida and Vienna.

Nocticolids are a small group (39 described species in ten genera) of Cockroaches found in tropical Africa, Southeast Asia, Papua-New Guinea, and Australia. They differ from other Cockroach groups in that they are flattened laterally rather than horizontally. Nocticolids are rather cryptic in their habits, and the group is not well studied in the wild; most of what we know about their biology comes from studies of colonies in labs, or the pet trade.

In a paper published in the journal Zootaxa on 5 May 2025, Junkai Wang of the Department of Entomology at Michigan State University, Alan Jeon of the Natural History Museum at Auburn University, and Anthony Cognato, also of the Department of Entomology at Michigan State University, describe a new, and apparently invasive, species of Nocticolid Cockroach from Florida and Vienna.

The new species was originally detected in the wild at University Park in Miami Dade County, Florida, where Alan Jeon collected several female specimens in June 2020.  In captivity, these were found to reproduce parthenogenetically, i.e. the female Cockroaches laid eggs without mating, which hatched into new females, also capable of producing fertile eggs without mating. This trait has not previously been recorded in Nocticolid Cockroaches, although it is known in several other Cockroach groups.

Because Nocticolid Cockroaches are not thought to be indigenous to the Americas, Wang et al. carried out a genetic analysis, in which they also included specimens from the US pet trade, which weren being traded under the name Nocticola sp. 'Malaysia', as well as specimens from a greenhouse at Schönbrunn  Zoo in  Vienna, Austria, where another all female colony of Nocticolid Cockroaches was reported.

The genetic study recovered all three populations as the same species, which Wang et al. name Nocticola vagus, where 'vagus' means 'wandering' in Latin, in reeference to the known distribution of the species. The original location of the Cockroaches traded as Nocticola sp. 'Malaysia' is unknown, but Nocticola vagus was recovered as the sister species to an un-named specimen from Vietnam in the genetic study. Thus, it is likely that the species originates in Southeast Asia, and possibly with a range that includes Peninsula Malaysia. A morphological comparison was more difficult, as many species of Nocticola are known only from male specimens, whereas all known specimens of Nocticola vagus are female.

Nocticola vagus female holotype. Habitus (A) frontal, (B) dorsal, (C) lateral, (D) ventral view and ootheca (E) lateral view. Wang et al. (2025).

Specimens of Nocticola vagus are described as 'small' (although Wang et al.do not provide measurements, and yellow or brown in colour. Their bodies are covered in short sensilla chaetica (sensory bristles). Each eye has eight ommatidia (the individual lenses of an Insect's compound eye), and the maxillary palps (mouthparts) each have five segments, making them almost as long as the head. 

See also...