Feeding Preferences and Responses of Monochamus saltuarius to Volatile Components of Host Pine Trees

SIMPLE SUMMARY: Bursaphelenchus xylophilus causes pine wilt disease, which is one of the most devastating forest diseases in the world. However, B. xylophilus cannot spread naturally and must be carried by vector insects from infested trees to healthy ones. Monochamus saltuarius is a B. xylophilus vector that has caused massive pine tree mortality in Japan, South Korea, and China’s middle temperate zone. In China, there have been only a few reports of this species. The feeding preference of M. saltuarius on different host pine trees was determined, and the volatile components of the host pine trees were analyzed. Furthermore, the responses of M. saltuarius to different host volatiles were determined, and the correlation between M. saltuarius preference and host pine tree volatiles was investigated. This study will serve as a reference for the development and application of M. saltuarius attractants, which will aid in the control of M. saltuarius and pine wilt disease. ABSTRACT: Monochamus saltuarius is a vector of Bursaphelenchus xylophilus and has caused massive mortality in pine trees in Japan, South Korea, and the middle temperate zone of China. In this study, the feeding preferences of M. saltuarius to four common host pine species in the middle temperate zone of China were investigated in a laboratory. The volatiles of the four host pine species were sampled and analyzed by gas chromatography and mass spectrometry. The responses of M. saltuarius to host pine tree volatiles were measured using a four-arm olfactometer. The results showed that: (1) the preference of M. saltuarius for Pine tabulaeformis was significantly higher than the other ones. (2) The composition and content of the volatiles of the four tested host pine twigs were different, and the relative content of α-pinene was the highest. (3) M. saltuarius was highly sensitive to α-pinene, β-pinene, limonene, and 3-carene, and the attracting effect was enhanced by the mixture of volatile components. This study provides a reference for the development and application of attractants for M. saltuarius. Our results would be helpful in controlling M. saltuarius and pine wilt disease.