Attraction of second‐stage juveniles of Meloidogyne species to fluopyram

Abstract

BACKGROUND Several benzenoid aromatic compounds were found to attract second‐stage juveniles (J2) of Meloidogyne species in previous studies. Here, the attraction of Meloidogyne J2 to the nematicides fluopyram and fluensulfone, with and without aromatic attractants, was evaluated on agar plates and in sand. RESULTS Fluensulfone mixed with 2‐methoxybenzaldehyde, carvacrol, trans‐cinnamic acid, and 2‐methoxycinnamaldehyde, attracted Meloidogyne javanica J2 on an agar plate, whereas fluensulfone alone did not. In contrast, fluopyram alone attracted J2 of M. javanica, Meloidogyne hapla, and Meloidogyne marylandi, although higher numbers of M. javanica J2 were attracted to the nematicide with the aromatic compounds. Trap tubes loaded with 1 and 2 μg fluopyram attracted M. javanica, Meloidogyne incognita, M. hapla, and M. marylandi J2 in the sand. Fluopyram‐treated tubes attracted 4.4–6.3 times higher numbers of M. javanica and M. marylandi J2 than fluensulfone. Potassium nitrate (KNO3), a Meloidogyne J2 repellent, did not abolish fluopyram's attractiveness to M. marylandi. These results indicate that high numbers of Meloidogyne J2 near fluopyram on an agar plate or in sand are caused by the attractiveness of the nematicide and not by the accumulation of dead J2 after their random encounter with the nematicide. CONCLUSION Aromatic attractants have the potential to attract Meloidogyne J2 to nematicides; however, fluopyram itself was attractive to Meloidogyne J2. The attractiveness of fluopyram to Meloidogyne J2 might contribute to its high control efficacy, and elucidation of the attraction mechanism could be useful for nematode‐control strategies. © 2023 Society of Chemical Industry.

3-(Methylthio)Propionic Acid from Bacillus thuringiensis Berliner Exhibits High Nematicidal Activity against the Root Knot Nematode Meloidogyne incognita (Kofoid and White) Chitwood

“…Due to their covert parasitic characteristics, controlling RKNs can be challenging [11]. Currently, the main control strategy against RKNs relies on chemical nematicides [12]. However, the use of certain effective chemical nematicides has been strictly banned in some countries due to their high toxicity to non-target organisms and the environment.…”