TY - JOUR
T1 - Helicoverpa zea males (Lepidoptera: Noctuidae) respond to the intermittent fine structure of their sex pheromone plume and an antagonist in a flight tunnel
AU - Fadamiro, Henry Y.
AU - Baker, Thomas C.
PY - 1997
Y1 - 1997
N2 - We investigated the behavioural response of male Helicoverpa zea (Boddie) to the fine-scale structure of an odour plume experimentally modified in a wind tunnel by using an air-pulsing device. Male H. zea flew upwind to pulsed filaments of a binary pheromone blend of (Z)-11-hexadecanal (Z11-16:Ald) and (Z)-9-hexadecanal (Z9-16:Ald) in the ratio of 20:1. Sustained upwind flight in experimentally altered intermittent plumes was dependent on concentration, as well as the frequency of generation of odour filaments. At a loading of 10 μg of the major pheromone component, Z11-16:Ald, which gave an emission rate of approximately that released by a female H. zea, sustained upwind flight and source contact correlated positively with filament delivery rate, becoming significant at a minimum filament delivery rate of 2/s. Decreases in upwind progress and source location were recorded at a loading of 1 μg of Z11-16:Ald. At this suboptimal dosage, a high filament generation rate of 10/s was necessary for significant upwind progress and source contact. When an interspecific compound: (Z)-11-hexadecenyl acetate (Z11-16:OAc), was added to the attractive pheromone binary aldehyde blend of H. zea at a proportion of 10% of the major pheromone component, and pulsed from the same source, there was a significant reduction in sustained upwind progress and source location by males, indicating that Z11-16:OAc is antagonistic to the upwind progress of H. zea. However, Z11-16:OAc was less antagonistic when its filaments were isolated and alternated with pheromone filaments, indicating a strong effect of the synchronous arrival of odour filaments on the antenna needed for antagonism of upwind flight.
AB - We investigated the behavioural response of male Helicoverpa zea (Boddie) to the fine-scale structure of an odour plume experimentally modified in a wind tunnel by using an air-pulsing device. Male H. zea flew upwind to pulsed filaments of a binary pheromone blend of (Z)-11-hexadecanal (Z11-16:Ald) and (Z)-9-hexadecanal (Z9-16:Ald) in the ratio of 20:1. Sustained upwind flight in experimentally altered intermittent plumes was dependent on concentration, as well as the frequency of generation of odour filaments. At a loading of 10 μg of the major pheromone component, Z11-16:Ald, which gave an emission rate of approximately that released by a female H. zea, sustained upwind flight and source contact correlated positively with filament delivery rate, becoming significant at a minimum filament delivery rate of 2/s. Decreases in upwind progress and source location were recorded at a loading of 1 μg of Z11-16:Ald. At this suboptimal dosage, a high filament generation rate of 10/s was necessary for significant upwind progress and source contact. When an interspecific compound: (Z)-11-hexadecenyl acetate (Z11-16:OAc), was added to the attractive pheromone binary aldehyde blend of H. zea at a proportion of 10% of the major pheromone component, and pulsed from the same source, there was a significant reduction in sustained upwind progress and source location by males, indicating that Z11-16:OAc is antagonistic to the upwind progress of H. zea. However, Z11-16:OAc was less antagonistic when its filaments were isolated and alternated with pheromone filaments, indicating a strong effect of the synchronous arrival of odour filaments on the antenna needed for antagonism of upwind flight.
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U2 - 10.1111/j.1365-3032.1997.tb01175.x
DO - 10.1111/j.1365-3032.1997.tb01175.x
M3 - Article
AN - SCOPUS:0031449646
SN - 0307-6962
VL - 22
SP - 316
EP - 324
JO - Physiological Entomology
JF - Physiological Entomology
IS - 4
ER -