Detecting invasive species with PCR and machine learning

With increasing trade and travel around the world more and more different species have been able to cross their natural geographical barriers and invade a new region. These kinds of biological invasions may pose threats to native fauna and flora, the economy and even human health, which is why doing thorough research on the invasive species is helpful for their effective management and quarantine.

The longan lanternfly (Pyrops candelaria) is a new invasive species on the main island of Taiwan. It was first observed in 2018 and was considered by Bureau of Animal and Plant Health Inspection and Quarantine (BAPHIQ) as a species that needed to be studied and removed. 

“Some Taiwanese people considered the longan lanternfly a native species, which has not been recorded before and objected to remove these insects from the main island of Taiwan. The results of our research have proved the invasion of the longan lanternfly,” says You-Sheng Lin, the main author of the study.

Because of their fascinating appearance lanternflies are very popular among collectors. The longan lanternfly is regarded as a mascot on Kinmen Islands. Their remarkable appearance makes them an excellent subject for environmental education and attracts many wildlife photographers. However, some lanternfly species could become serious pests. For example, the spotted lanternfly (Lycorma delicatula) causes great economic losses to the grape industry.
The invasive longan lanternfly, Pyrops candelaria, stayed with a native lanternfly species from Taiwan, Pyrops watanabei.

The research conducted by You-Sheng Lin and his colleagues aimed to infer the invasion history of longan lanternfly, predict habitat suitability, potential expansion and assess the risk to crop cultivation areas in Taiwan. This was done using genetic analysis and machine learning. The genetic structures of P. candelaria from the main island of Taiwan and related regions were analyzed based on partial COI and ND2 sequences.
“I chose two genes as markers for investigating the invasion source of longan lanternfly. To amplify the ND2 gene using PCR, I designed a pair of species-specific primers for the longan lanternfly, which have never been used in the other studies,” explains You-Sheng Lin.

The results suggested that the Taiwanese populations of longan lanternfly may originate from the Kinmen Islands. In addition, the comparison of potential distribution and crop locations revealed high risk to both longan and pomelo, which showed high habitat suitability for P. candelaria.

This study can be used as a reference for quarantine policies aimed at outlying islands and for environmental education about exotic species. The research group’s future studies will focus on developing higher resolution molecular markers to assess the expansion pattern of longan lanternfly. 
Solis BioDyne product used: FIREPol® Master Mix
“The Solis BioDyne product I used was the 5x FIREPol® Master Mix. This product includes not only DNA polymerase, ddNTPs, and buffer used for PCR, but also loading dye used for electrophoresis. With this product, researchers can save a lot of time and efforts on experiments,” says You-Sheng Lin, the main author of the paper. He adds that he would recommend this product to others and has already done so.
Lin, Y. S., Liao, J. R., Shiao, S. F., & Ko, C. C. (2021). Origin and Potential Expansion of the Invasive Longan Lanternfly, Pyrops candelaria (Hemiptera: Fulgoridae) in Taiwan. Biology, 10(7), 678.