Effect of Bursaphelenchus xylophilus (Nematoda: Aphelenchoididae) fourth stage dispersal juveniles and log seasonality on life processes of Monochamus carolinensis (Coleoptera: Cerambycidae)

The pinewood nematode, Bursaphelenchus xylophilus (Steiner and Buhrer) Nickle, and its cerambycid beetle vector, Monochamus carolinensis (Olivier), have a commensal relationship. The nematode is transported from infested trees to new host trees by Monochamus beetles. The influence of nematode load (the number of nematodes carried per beetle), seasonal rearing in pine logs, and the mated status of female beetles on the life processes of M. carolinensis were investigated. Increasing nematode load had a slight negative effect on the reproductive potential of M. carolinensis females. Beetles that emerged from logs cut during the spring had a higher reproductive potential than those emerging from logs cut during the summer or autumn. The flight performance (flight distance, duration, and speed) of M. carolinensis was negatively affected by nematode load when individuals carried 10,000 or more nematodes. Unmated females outperformed their mated counterparts on all flight measure tests.