Sex pheromone production and response in Korean populations of the diamondback moth, Plutella xylostella

Abstract The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Yponomeutidae), is a worldwide pest of cruciferous crops. We examined the female pheromone production and male response to various pheromone blends in two Korean populations. Gas chromatography (GC) and GC‐mass spectrometry (MS) analyses of pheromone gland extracts revealed that females produce ( Z )‐11‐hexadecenal ( Z 11‐16:Ald), ( Z )‐11‐hexadecenyl acetate ( Z 11‐16:OAc), and ( Z )‐11‐hexadecen‐1‐ol ( Z 11‐16:OH) in a ratio of 8:100:18. However, ( Z )‐9‐tetradecenyl acetate ( Z 9‐14:OAc), a previously reported component of the sex attractant of a Canadian P. xylostella population was not detected in gland extracts of the Korean one. Field tests showed that Z 11‐16:Ald and Z 11‐16:OAc are essential for attraction of male moths, and the highest attraction is obtained with a 10:90 blend mimicking the blend found in gland extracts. Addition of 1 or 10% of Z 11‐16:OH to the 10:90 blend of Z 11‐16:Ald and Z 11‐16:OAc significantly increased attraction. However, attraction was strongly antagonized by the addition of as little as 0.1% of Z 9‐14:OAc to the most attractive ternary blend. The ternary blend of Z 11‐16:Ald, Z 11‐16:OAc, and Z 11‐16:OH at a ratio of 10:90:1 was more effective at catching P. xylostella males than the Japanese three‐component blend or the Canadian four‐component blend in Korea. These results suggest that there is geographical variation in the pheromone systems of this species.