Aromatic compounds that attract Meloidogyne species second‐stage juveniles in soil

• Published in: Pest management science Vol. 77; no. 10; pp. 4288 - 4297
• Main Author: Oka, Yuji
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.10.2021; Wiley Subscription Services, Inc
• Subjects: Acidic soils; Acids; Alcohols; Aldehydes; Aromatic compounds; Assaying; Attractants; attraction assay; Benzoic acid; Cinnamic acid; Dune sand; Exudates; Exudation; Inoculation; Juveniles; Meloidogyne; Meloidogyne hapla; Meloidogyne species; Nematicides; nematode attractant; Nematodes; p-Hydroxybenzoic acid; Phenols; root‐knot nematode; Salicylic acid; Sand; Soils; Species; Tubes; Vanillin
• ISSN: 1526-498X; 1526-4998
• DOI: 10.1002/ps.6506

BACKGROUND Nematode attractants could serve in nematode control strategies by combining with chemical or biological nematicides or by interrupting the nematodes' host‐finding process. The attractiveness of some benzenoid aromatic compounds, mainly benzoic acids, alcohols, aldehydes and phenols, to second‐stage juveniles (J2) of four Meloidogyne species (M. hapla, M. incognita, M. javanica and M. marylandi) was evaluated by using trap tubes and balls filled with washed dune sand buried in nematode‐inoculated sand in Petri dishes. RESULTS Two‐methoxybenzaldehyde, 2‐methoxycinnamaldehyde, 2‐hydroxybenzoic acid (salicylic acid), 2‐hydroxy‐3‐methoxybenzaldehyde (o‐vanillin), 3‐methoxybenzoic acid, 4‐methoxybenzoic acid and trans‐cinnamic acid effectively attracted J2 of all or most of the four Meloidogyne species to trap tubes in a one‐compound assay. When nematodes were exposed to three different compounds simultaneously in the three‐compound assay, J2 of all Meloidogyne species were attracted mainly to 2‐methoxycinnamaldehyde, salicylic acid and 4‐methoxybenzoic acid. Exceptions were M. hapla J2, which were not attracted to salicylic acid. In the soil column assay, M. javanica and M. incognita J2 were attracted upward to 4‐methoxybenzoic acid in a trap ball located 4 or 8 cm above the inoculation point, whereas salicylic acid and 3‐methoxybenzoic acid demonstrated slight, if any attraction. CONCLUSION Although some of the tested compounds exist in root exudates, it is not clear whether they are involved in the nematode host‐searching process in nature. The attractants found in the study have potential for use in Meloidogyne species control, probably as a nematode trap constituent or as compounds that disrupt the nematodes' host‐finding process. © 2021 Society of Chemical Industry. The attractiveness of some benzenoid aromatic compounds to second‐stage juveniles (J2) of four Meloidogyne species (M. hapla, M. incognita, M. javanica and M. marylandi) was evaluated by using trap tubes and balls filled with sand buried in nematode‐inoculated sand. 2‐Methoxybenzaldehyde, 2‐methoxycinnamaldehyde, salicylic acid, o‐vanillin, 3‐methoxybenzoic acid, 4‐methoxybenzoic acid and trans‐cinnamic acid effectively attracted J2 of most of the four species to trap tubes in a one‐compound assay. When they were exposed to three different compounds simultaneously in the three‐compound assay, J2 of all nematode species were attracted mainly to 2‐methoxycinnamaldehyde, salicylic acid and 4‐methoxybenzoic acid, except for M. hapla J2, which were not attracted to salicylic acid. In the soil column assay, M. javanica and M. incognita J2 were attracted upward to 4‐methoxybenzoic acid in the trap ball located 4 or 8 cm above the inoculation point. The attractants found in the study have potential for use in root‐knot nematode control, probably as a nematode trap constituent and as compounds that disrupt the nematodes' host‐finding process.