Low risk associated with the import and keeping of Turkestan cockroach

Thus concludes a risk assessment of the non-native cockroach species Periplaneta lateralis, conducted by the Norwegian Scientific Committee for Food and Environment (VKM) on behalf of the Norwegian Environment Agency.

Background

The Turkestan cockroach is one of several insect species used as feed for reptiles, spiders, scorpions, mantises, and other invertebrates kept as hobby animals in Norway. The Norwegian Environment Agency has received three separate applications for the import of this species.
On the basis of these applications, the Agency requested an assessment of the potential risks that importation may pose to biodiversity in Norway. In particular, they were interested in whether the species could establish under current climatic conditions, and how climate change might affect the likelihood of establishment.

Methods

VKM first assessed how likely it is that the species can survive and establish populations in Norwegian nature. This assessment was based on a climate suitability model, which compares Norwegian climatic conditions with those in regions where the species has been observed.

VKM also reviewed available scientific literature to evaluate potential negative impacts if the species were to establish itself. Two mechanisms through which the species could have a negative impact were identified:

• Competition with native species
• Transmission of pathogens

Risk assessments were conducted for each of these factors. Additionally, VKM proposed possible risk mitigation measures.

Results

VKM’s model clearly indicates the Norwegian climate is too cold and wet for the species to survive in natural habitats in Norway. However, the cockroach is often found near human settlements and thrives in man-made habitats such as warehouses and electrical cabinets. Thus, survival in Norway may be possible in such environments.
Nevertheless, VKM concludes that even in artificial habitats, it is highly unlikely that conditions would be warm enough, and for a sufficient period of time, for the species to reproduce.
Should the species manage to survive in the long term, VKM concludes that the risk of competition with native species and transmission of disease-causing organisms is low.

“This species originates from very hot and dry regions in Central Asia—conditions that are the exact opposite of those found in Norway,” says Lawrence Kirkendall, scientific lead for the assessment.

VKM also evaluated how climate change—primarily increased temperature and precipitation—might affect the species’ potential for establishment in Norway.

“When we consider projected climate conditions towards 2040, we see that the species may thrive in some new areas in Central Europe around the Mediterranean. However, most of Europe will remain highly unsuitable for this cockroach,” says Kirkendall.

Although the species is associated with low risk, there is little indication that large quantities would be imported even if permission were granted, as more suitable species are already available in Norway.

The risk assessment has been approved by VKM’s Panel on Biodiversity.

Photo: Happy1892 at English Wikipedia, CC BY-SA 3.0, via Wikimedia Commons. Cropped.