Studies on the flight capabilities of Polygraphus proximus
A study has been conducted in Russia to evaluate the flight capabilities of Polygraphus proximus (Coleoptera: Curculionidae: Scolytinae – EPPO A2 List). The objective of this study was to determine, through empirical and modeling approaches, the maximum distance that young P. proximus beetles can fly under natural conditions. A field experiment was conducted in a region where P. proximus occurs (Emelyanovsky district, Kranoyarsk krai). An experimental plot of approximately 1.5 x1.5 km was selected in a zone where P. polygraphus is absent (i.e. at least 2 km away from fir stands) and without host trees (i.e. with no large fir trees). The experiment used slabs (sections of bark with a thin sapwood layer) with beetles hibernating under the bark, and traps made of short logs of Abies sibirica with no signs of P. proximus infestation. The experiment was conducted from May to July 2023, a period during which weather conditions allow flight dispersal. Trap logs were placed at distances ranging from 50 to 1500 m in the four cardinal directions from the release point to attract beetles. Once the overwintering beetles had left the slabs, the number of parental pairs (male and female) on the trap logs and their number per dm² were evaluated. In addition, a model was used to estimate potential flight distances. Experimental data showed that the maximum flight distance of P. proximus was 1500 m. Using the model, it was estimated that the potential flight range of P. proximus is approximately 3 000 to 5000 m.
Sources
Demidko DA, Kulakov SS, Efremenko AA, Babichev NS, Barchenkov AP, Mikhailov PV (2024) Assessing the flight potential of the four-eyed fir bark beetle Polygraphus proximus Blandford in natural conditions. Forests 15(8), 1316. https://doi.org/10.3390/f15081316