Rapid Diagnosis of the Infection of Pine Tree with Pine Wood Nematode (Bursaphelenchus xylophilus) by Use of Host-Tree Volatiles

Abstract

Attraction of the Bursaphelenchus xylophilus nematode toward 18 volatiles of Pinus species was evaluated by a Petri-dish bioassay under laboratory conditions to develop a rapid diagnostic kit. Among these compounds, α-pinene, β-pinene, and camphor showed significantly higher attractiveness to B. xylophilus in both the reproductive and dispersal stages, whereas these compounds were not active against Bursaphelenchus mucronatus. A trap tube was developed as a diagnostic kit, which consisted of a tube filled with 0.8% agar and a matrix impregnated with an attractant: α-pinene, β-pinene, or camphor. All tested compounds attracted a significantly higher number of B. xylophilus than that in the control treatment. No significant difference was observed among attractants. The cotton-ball matrix was significantly more effective than the filter-paper matrix for attracting B. xylophilus in the artificial pupal chamber bioassay. In a bioassay with pine wood nematode (PWN)-infected pine tree logs, B. xylophilus was initially attracted after an 8 h trap period and the number of B. xylophilus increased with time. The trap tube using camphor and the cotton-ball matrix were most effective for attracting B. xylophilus. The semiochemical-based tube-trapping method is simple to use, requires minimal labor, and is economical and effective for detecting B. xylophilus living in host pine trees during field sampling.

Effects of α-pinene on the pinewood nematode (Bursaphelenchus xylophilus) and its symbiotic bacteria

“…The nematocidal activity of pinene was low (LC 50 > 1.0 mg mL −1 ) with treatment of 26 monoterpenoids, including pinene [23]. In the present study, α-pinene had low toxicity to PWNs over a short time period, which is consistent with previously reported results [11,23]. Pinene also has no obvious toxicity in C .…”

“…The results showed that α-pinene applied by fumigation had a certain degree of influence on the survival of nematodes, which differed slightly from previous results obtained by adding nematodes directly to α-pinene solution (LD 50 > 20 mg mL −1 ) [11]. The nematocidal activity of pinene was low (LC 50 > 1.0 mg mL −1 ) with treatment of 26 monoterpenoids, including pinene [23]. In the present study, α-pinene had low toxicity to PWNs over a short time period, which is consistent with previously reported results [11,23].…”

Host Deception: Predaceous Fungus, Esteya vermicola, Entices Pine Wood Nematode by Mimicking the Scent of Pine Tree for Nutrient

“…Yun et al reported that α-pinene, β-pinene, and camphor were highly attractive to PWN and camphor showed significantly higher attractiveness to the PWNs among the three chemicals in the PWN-infected pine tree log bioassay [12]. More interestingly, our research results demonstrated that E. vermicola resorted to host deception, in which this living predaceous fungus enticed PWN by producing VOCs (α-pinene, β-pinene, and camphor) that mimicked the scent of PWN host pine tree for nutrient.…”

“…To date, the most researchers use Petri dish method to study attractive VOCs to nematodes from microbes [6], [12]. The STM bioassay provides a simple and effective way to assist identification of attractive VOCs to nematodes from microbes.…”

Two terpene synthases in resistant Pinus massoniana contribute to defence against Bursaphelenchus xylophilus

“…The oven program temperature started at 50 C (2-min hold), and then ramped to 80 C at a rate of 3 C min −1 (2-min hold), followed by a second ramp to 180 C at a rate of 5 C min −1 (1-min hold), and a third ramp to 230 C at a rate of 10 C min −1 (1-min hold), and then a final ramp to 250 C at a rate of 20 C min −1 (3-min hold Figure S5 in Data S1). PWNs were cultured under the same environmental conditions at 25 C for 24 hr (Yun, Kim, & Park, 2012). The experiment was replicated three times.…”