Canadian Forest Service Publications

Citizen monitoring of invasive species: wing morphometry as a tool for detection of alien Tetropium species. 2017. Goczal, J.; Rossa, R.; Sweeney, J.D.; Tofilski, A. Journal of Applied Entomology 141: 496-506.

Year: 2017

Issued by: Atlantic Forestry Centre

Catalog ID: 38986

Language: English

Availability: PDF (download)

Available from the Journal's Web site.
DOI: 10.1111/jen.12370

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The increasing threat of alien wood-boring insect has resulted in the initiation of large-scale monitoring programmes. These programmes are most often based on pheromone-bailed traps, which allow the early detection and monitoring of invasive species. This approach is expensive because it entails the processing and accurate identification of large numbers of specimens. One of the most often suggested solutions to this problem is citizen participation in the monitoring of invasive species. Such an approach has the potential for reducing costs as well as providing data from a larger number of sites. However, citizens vary in taxonomic expertise and experience which can result in identification errors. This may be particularly important in the case of wood borers which include many morphologically similar species. In this study, we develop and discuss a semi-auto-mated method of identifying four morphologically similar and invasive Tetropium spp. wood borers as a potential tool for citizen-based monitoring programmes. Identification is based on wing measurements and requires neither specialist knowledge nor expensive equipment. The method correctly identified the species of Tetropium with an error ranging from 1.3%for T. fuscum to 7.5% for T. cinnamopterum. We found that experience level of the individual user was not essential for correct identification; on average, inexperienced volunteers correctly identified the Tetropium species in 93% of cases. Further development of this method may be a significant step to overcoming the taxonomical impediment to citizen monitoring of taxonomically challenging groups of insects.

Plain Language Summary

Global trade and the movement of large volumes of containerized goods between continents sometimes results in the accidental introductions of insects from Asia or Europe to North America and vice versa. Wood boring beetles that can live for months inside the wood used to pack many of these goods are especially prone to introduction, and some of them become invasive and damaging forest pests. Trapping surveys are conducted every year in major ports and large cities in an effort to detect these introductions as early as possible. Much of the cost of these surveys is in the labor required to sort beetles captured in traps and identify the species present. Citizen science offers a potential way of reducing costs as well as providing data from a larger number of sites. However, most citizens lack the specialized knowledge required to identify the many kinds of beetles that may be present in traps. This study describes a relatively simple method that citizen scientists could use to distinguish four species of wood boring beetles in the same genus (Tetropium spp.). The method requires the citizen to remove a wing, place it flat between two glass slides, scan the wing on a home photocopier/printer, and then use a software package to mark 17 spots on the wing. The software then identifies the species of Tetropium based on the wing shape and measurements. We tested the method with inexperience volunteers and found their accuracy of identification was 93%. Further development of this and similar methods may help to involve interested citizens in the monitoring of invasive species.