Biology and associated fungi of an emerging bark beetle pest, the sweetgum inscriber Acanthotomicus suncei
Description
The sweetgum inscriber (SI) Acanthotomicus suncei Cognato is an emerging bark beetle pest that seriously damages American sweetgum trees (Liquidambar styraciflua) and Chinese sweetgum trees (L. formosana) in China. Since 2013, SI has killed more than 30,000 sweetgum trees in Shanghai and adjacent areas. In Shanghai, SI emerged from infested wood from April to September and exhibited two generations per year. Both the flying populations and those in colonized logs were female-biased. After the parental adult bored a gallery, the emergence of new adults required 73.37± 0.69 days at 30 °C and 163.46 ± 0.94 days at 20 °C. SI could not sustain population development at constant temperatures ≤ 15 °C. The fungi Geosmithia spp. and Phaeoacremonium tuscanum were common associates of SI. The results suggest that SI has a long flight periodicity, and its development is sensitive to low temperatures. Fungi associated with SI were not pathogenic to American sweetgum trees, but their presence as mutualists may support the beetle’s mass attack and thereby indirectly increase the probability of tree mortality. Our findings contribute to the prevention and control of this important emerging bark beetle pest