Antagonistic effect of (Z)-11-hexadecen-1-ol on the pheromone-mediated flight of Helicoverpa zea (Boddie)(Lepidoptera: Noctuidae) (original) (raw)
Related papers
1997
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 (Zll-16:Ald) and (Z)-9-hexadecanal (Z9-16:Ald) in the ratio of 20:1. Sustained ~pwind 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 ~g of the major pheromone component, Zll-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 ~g of Zll-16:A1d. 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)-ll-hexadecenyl acetate (Zll-16:0Ac), 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 Zll-16:0Ac is antagonistic to the upwind progress of H. zea. However, Zll-16:0Ac 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.
Responses of male Helicoverpa zea to single pulses of sex pheromone and behavioural antagonist
2001
Male Hehcoverpa zea (Boddie) (Lepidoptera: Noctuidae) flying in a pheromone plume respond to the loss of pheromone when they fly into a large pocket of clean air by going into crosswind casting flight in a mean of 0 48 s; 0 62 s after re-contacting pheromone presented as a single pulse, they surge upwind in a kind of narrow zigzagging flight After 0 36 s of surging, they lapse into casting flight once again in the clean air following the pulse The addition of a known behavioural antagonist (Z)-11-hexadecenyl acetate (Zll-16:Ac), to the pheromone significantly increases the mean latency of the response to a single pulse to 0 85 s No other aspects of the surge were significantly changed by the presence of antagonist in the single pulse of pheromone Thus, unlike males of the related species, Heliothis virescens, which show significant changes in track and course angles when antagonist is present in single pulses, only an increased latency of response to a filament containing antagonist occurred in H zea males The increased latency could act cumulatively when the male is exposed rapidly and repeatedly to filaments in a natural plume and explain the profound arrestment effect of the antagonist in such plumes The latencies to casting and surging in response to a pulse of pheromone blend are longer than those of the smaller species, H virescens, and may be due to size-related differences in manoeuverability of H zea vs H vzrescens
Journal of Comparative Physiology A: Sensory, Neural, and Behavioral Physiology, 1999
The limits of a male moth's ability to resolve closely spaced odor ®laments have been investigated. Male Helicoverpa zea normally respond to their con-speci®c sex pheromone blend by exhibiting an upwind ight, which culminates in source contact by at least 50% of the bioassayed individuals. When loaded onto the same ®lter paper source containing this hitherto attractive pheromone blend, or onto a separate ®lter paper and co-emitted from the same pipette source with pheromone, (Z)-11-hexadecenyl acetate severely reduced up-wind¯ight and source contact by male H. zea. A similar level of upwind¯ight inhibition was recorded when the antagonist (Z)-11-hexadecenyl acetate was emitted from its own point source placed 1 mm upwind of the pheromone point source, both plumes being simultaneously emitted in a continuous mode to form a con¯uent strand. However, (Z)-11-hexadecenyl acetate was less eective in reducing upwind¯ight and source contact when it was isolated and pulsed from its own source, placed 1 mm either upwind, downwind or cross-wind of a pipette source from which pheromone was simultaneously being pulsed, such that both ®laments were separated in time by 0.001±0. 003 s. These results suggest that male H. zea are able to distinguish between odor sources separated by as little as 1 mm in space and 0.001 s in time.
Entomologia Experimentalis et Applicata, 1993
Three sex pheromonal components, (Z)-ll-hexadecenal (Zll-16:Ald), (Z)-ll-hexadecenol (Zll-16:OH), and hexadecanal (16:Aid), in a ratio of 88.0:7.2:4.8, were identified from ovipositor extracts of the fulvous clover moth, Heliothis maritima Grasl. (Lepidoptera: Noctuidae) by gas chromatographymass spectrometry. In addition, trace amounts of (Z)-9-hexadecenal (Z9-16:AId)were detected in the extracts by GC. A blend of Zll-16:AId, Zll-16:OH and 16:Ald in a ratio of 100:6:3, as well as in combination with 0.1 or 1 part Z9-16:Aid was tested at 0.01, 0.1, 1.0 and 10.0 btg doses in a flight tunnel. In flight tunnel tests male behavioral responses elicited by 0.1 or 1.0 #g doses of the 100:6:3:1 blend were similar to those elicited by an ovipositor extract at 2 female equivalents. Deletion of Z9-16:Ald from the blend at 0.1 #g dose caused a decrease in the male response. In the field test, however, presence or absence of Z9-16:AId did not significantly influence the number of males trapped in sticky traps with rubber septa containing 100/~g of the respective blends.
Journal of Comparative Physiology A, 1995
The behavioural significance of (Z)-9-tetradecenal to male H. assulta was tested by comparing the number of moths attracted to lures containing a standard synthetic female sex pheromone with lures in which (Z)-9-tetradecenal was also added. The standard pheromone mixture used contained 1000lag (Z)-9-hexadecenal, 50 lag (Z)-ll-hexadecenal, 300 lag (Z)-9-hexadecenyl acetate and 15lag (Z)-ll-hexadecenyl acetate impregnated on rubber septa. Addition of (Z)-9-tetradecenal to the standard pheromone was shown to significantly reduce the caught of male H. assulta when added in amounts greater than 10 tag or 1% of the major pheromone component in both field and net-house experiments. The reduction in catch was found to be dependent on the quantity of (Z)-9-tetradecenal added to the standard pheromone. The implications of these results on conspecific and interspecific pheromone-mediated communication in H. assulta and related sympatric heliothine species is discussed.
New Zealand Plant Protection, 2018
Epiphyas postvittana is a major horticultural pest in many countries, including New Zealand. Recently, two minor components (E)-11-tetradecen-1-ol and (E)-11-hexadecenyl acetate were found to increase the attraction of a previously identified two-component sex pheromone (95:5 blend of (E)-11-tetradecenyl acetate [E11-14:Ac] and (E,E)-9,11-tetradecadienyl acetate [E9,E11-14:Ac]) of Epiphyas postvittana. We hypothesised that the interaction between these minor components and the behavioural antagonist (Z)-11-tetradecenyl acetate (Z11-14:Ac) would modulate its antagonistic effect. The effect of increasing the ratio (0.5—10%) of Z11-14:Ac was tested in traps baited with E11-14:Ac and E9,E11-14:Ac (95:5), with or without the addition of the two minor compounds. Catch decreased as the percentage of Z11-14:Ac increased (χ2=108.74; d.f.=9;…
Environmental Entomology, 2013
Sensory adaptation has been measured in the antennae of male Grapholita molesta (Busck) after 15 min of exposure to its main pheromone compound (Z)-8-dodecen-1-yl acetate (Z8-12:OAc) at the aerial concentration of 1 ng/m 3 measured in orchards treated with pheromone for mating disruption. Exposing males to this aerial concentration of Z8-12:OAc for 15 min, however, had only a small effect on their ability to orientate by ßight to virgin calling females in a ßight tunnel. Experiments were undertaken to determine if exposure to the main pheromone compound in combination with the two biologically active minor compounds of this species, (E)-8-dodecen-1-yl acetate (E8-12:OAc) and (Z)-8-dodecen-1-ol (Z8-12:OH) would induce greater levels of sensory adaptation and have a greater effect on male sexual behavior. The exposure of male antennae to 0.5 g/m 3 air of one of the three pheromone compounds induced sensory adaptation to this compound and to the other two pheromone compounds demonstrating cross adaptation. Average percentage sensory adaptation to a pheromone compound was similar after 15 min of exposure to 1 ng/m 3 air of Z8-12:OAc, or to 1 ng/m 3 air of a 1:1:1 or 93:6:1 blend of Z8-12:OAc, E8-12:OAc, and Z8-12:OH. The exposure of males to 1 ng/m 3 air of Z8-12:OAc or the two ratios of Z8-12:OAc, E8-12:OAc, and Z8-12:OH for 15 min had no effect on their ability to orientate to a virgin calling female. The implications of these results for the operative mechanisms of sex pheromone-mediated mating disruption of this species are discussed.
Chemical communication in heliothine moths
1991
Helicoverpa zea males flew upwind and successfully contacted the source when presented with 2component blends consisting of their principal conspecific sex pheromone component, (Z)-11-hexadecenal, plus small amounts of (Z)-9-tetradecenal, a key secondary component in the Heliothzs vzrescens blend which has heretofore been considered antagonistic to H. zea pheromone-mediated behavior Neurophysiological studies of H zea antennal receptor neurons and central interneurons had suggested that this unexpected antagonistic effect on behavior might occur 2 When the amount of (Z)-9-tetradecenal in the blend reached 15% relative to the principal component its effect did become antagonistic with significantly more H zea males remaining quiescent Five-to-fifteen per cent (Z)-9-tetradecenal is emitted by H virescens in its pheromone blend, levels that evoked optimal upwind flight and source contact in H vzrescens males 3 As suggested by studies of H virescens antennal receptor neurons, H vzrescens males were unresponsive to the reciprocal inter-specific blend, comprised of (Z)-11-hexadecenal plus various percentages of (Z)-9-hexadecenal 4 Receptors that allow such mutual replacement of compounds might permit significant shifts in pheromone systems; a single mutation that drastically alters the female sex pheromone blend could still be carried in a population due to the successful attraction of normal males by mutant females Key words: Sex pheromones-Antenna1 neurons-(Z)-11-hexadecenal-Helicoverpa zea-Heliothis virescens
Responses of maleHelicoverpa zeato single pulses of sex pheromone and behavioural antagonist
Physiological Entomology, 2001
Male Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) flying in a pheromone plume respond to the loss of pheromone when they fly into a large pocket of clean air by going into crosswind casting flight in a mean of 0.48 s; 0.62 s after re-contacting pheromone presented as a single pulse, they surge upwind in a kind of narrow zigzagging flight. After 0.36 s of surging, they lapse into casting flight once again in the clean air following the pulse. The addition of a known behavioural antagonist (Z)-11-hexadecenyl acetate (Zl l-16:Ac), to the pheromone significantly increases the mean latency of the response to a single pulse to 0.85 s. No other aspects of the surge were significantly changed by the presence of antagonist in the single pulse of pheromone. Thus, unlike males • of the related species, Heliothis virescens, which show signifi cant changes in track and course angles when antagonist is present in single pulses, only an increased latency of response to a filament containing antagonist occurred in H. zea males. The increased latency could act cumulatively when the male is exposed rapidly and repeatedly to fi laments in a natural plume and explain the profound arrestment effect of the antagonist in such plumes. The latencies to casting and surging in response to a pulse of pheromone blend are longer than those of the smaller species, H. virescens, and may be due to size-related differences in manoeuverability of H. zea vs. H. virescens.