Limits...
Pheromone mediated modulation of pre-flight warm-up behavior in male moths.

Crespo JG, Goller F, Vickers NJ - J. Exp. Biol. (2012)

Bottom Line: This resulted in less time spent shivering and faster heating rates.Two interesting results emerge from these experiments.Our results shed light on thermoregulatory behaviour of unrestrained moths associated with the scramble competition for access to females and suggest ecological trade-offs between rapid flight initiation and sub-optimal flight performance.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, University of Utah, Salt Lake City, UT 84112, USA. jose.crespo@utah.edu

ABSTRACT
An essential part of sexual reproduction typically involves the identification of an appropriate mating partner. Males of many moth species utilize the scent of sex pheromones to track and locate conspecific females. However, before males engage in flight, warm-up by shivering of the major flight muscles is necessary to reach a thoracic temperature suitable to sustain flight. Here we show that Helicoverpa zea males exposed to an attractive pheromone blend (and in some instances to the primary pheromone component alone) started shivering earlier and took off at a lower thoracic temperature than moths subjected to other incomplete or unattractive blends. This resulted in less time spent shivering and faster heating rates. Two interesting results emerge from these experiments. First, the rate of heat generation can be modulated by different olfactory cues. Second, males detecting the pheromone blend take off at lower thoracic temperatures than males exposed to other stimuli. The take-off temperature of these males was below that for optimal power production in the flight muscles, thus generating a trade-off between rapid departure and suboptimal flight performance. Our results shed light on thermoregulatory behaviour of unrestrained moths associated with the scramble competition for access to females and suggest ecological trade-offs between rapid flight initiation and sub-optimal flight performance.

Show MeSH

Related in: MedlinePlus

Helicoverpa zea male orientation at take-off whenexposed to different female pheromone compounds. Each point represents asingle individual and arrows indicate the preferred direction (Rayleightest). S indicates the position of the odor source. Treatments are asfollows: attractive, Z11-16:Ald + Z9-16:Ald; primary component,Z11-16:Ald; non-attractive, Z11-16:Ald + Z9-16:Ald + Z11-16:OAc;secondary component, Z9-16:Ald; primary component + acetate, Z11-16:Ald+ Z11-16:OAc; and blank, hexane. The averaged preferred take-off angles(a), Rayleigh vector lengths (r),z-statistics (z), sample sizes(n) and P-values are shown foreach treatment.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3368620&req=5

Figure 1: Helicoverpa zea male orientation at take-off whenexposed to different female pheromone compounds. Each point represents asingle individual and arrows indicate the preferred direction (Rayleightest). S indicates the position of the odor source. Treatments are asfollows: attractive, Z11-16:Ald + Z9-16:Ald; primary component,Z11-16:Ald; non-attractive, Z11-16:Ald + Z9-16:Ald + Z11-16:OAc;secondary component, Z9-16:Ald; primary component + acetate, Z11-16:Ald+ Z11-16:OAc; and blank, hexane. The averaged preferred take-off angles(a), Rayleigh vector lengths (r),z-statistics (z), sample sizes(n) and P-values are shown foreach treatment.

Mentions: Because male moths fly upwind to a pheromone source, it was expectedthat they would also orient upwind at take-off. Fig. 1 shows that the take-off direction of males exposed to theattractive blend (Rayleigh test,P<10–4), as well as to theprimary component alone (Rayleigh test, P=0.02), wassignificantly oriented toward the source (i.e. upwind). During exposure to theother treatments (in which the pheromone blend was altered or completelyabsent), males took off in random directions (Rayleigh test,P>0.1). These behavioral data not only show that malesare attracted to the pheromone blend but also that the experimental approachutilized in this study (see Materials and methods) is appropriate for evaluatingthe pre-flight behavior of male moths. Furthermore, at least 80% of males testedin all treatments took off (data not shown), and no differences were foundbetween treatments (chi-square test, P>0.08).


Pheromone mediated modulation of pre-flight warm-up behavior in male moths.

Crespo JG, Goller F, Vickers NJ - J. Exp. Biol. (2012)

Helicoverpa zea male orientation at take-off whenexposed to different female pheromone compounds. Each point represents asingle individual and arrows indicate the preferred direction (Rayleightest). S indicates the position of the odor source. Treatments are asfollows: attractive, Z11-16:Ald + Z9-16:Ald; primary component,Z11-16:Ald; non-attractive, Z11-16:Ald + Z9-16:Ald + Z11-16:OAc;secondary component, Z9-16:Ald; primary component + acetate, Z11-16:Ald+ Z11-16:OAc; and blank, hexane. The averaged preferred take-off angles(a), Rayleigh vector lengths (r),z-statistics (z), sample sizes(n) and P-values are shown foreach treatment.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3368620&req=5

Figure 1: Helicoverpa zea male orientation at take-off whenexposed to different female pheromone compounds. Each point represents asingle individual and arrows indicate the preferred direction (Rayleightest). S indicates the position of the odor source. Treatments are asfollows: attractive, Z11-16:Ald + Z9-16:Ald; primary component,Z11-16:Ald; non-attractive, Z11-16:Ald + Z9-16:Ald + Z11-16:OAc;secondary component, Z9-16:Ald; primary component + acetate, Z11-16:Ald+ Z11-16:OAc; and blank, hexane. The averaged preferred take-off angles(a), Rayleigh vector lengths (r),z-statistics (z), sample sizes(n) and P-values are shown foreach treatment.
Mentions: Because male moths fly upwind to a pheromone source, it was expectedthat they would also orient upwind at take-off. Fig. 1 shows that the take-off direction of males exposed to theattractive blend (Rayleigh test,P<10–4), as well as to theprimary component alone (Rayleigh test, P=0.02), wassignificantly oriented toward the source (i.e. upwind). During exposure to theother treatments (in which the pheromone blend was altered or completelyabsent), males took off in random directions (Rayleigh test,P>0.1). These behavioral data not only show that malesare attracted to the pheromone blend but also that the experimental approachutilized in this study (see Materials and methods) is appropriate for evaluatingthe pre-flight behavior of male moths. Furthermore, at least 80% of males testedin all treatments took off (data not shown), and no differences were foundbetween treatments (chi-square test, P>0.08).

Bottom Line: This resulted in less time spent shivering and faster heating rates.Two interesting results emerge from these experiments.Our results shed light on thermoregulatory behaviour of unrestrained moths associated with the scramble competition for access to females and suggest ecological trade-offs between rapid flight initiation and sub-optimal flight performance.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, University of Utah, Salt Lake City, UT 84112, USA. jose.crespo@utah.edu

ABSTRACT
An essential part of sexual reproduction typically involves the identification of an appropriate mating partner. Males of many moth species utilize the scent of sex pheromones to track and locate conspecific females. However, before males engage in flight, warm-up by shivering of the major flight muscles is necessary to reach a thoracic temperature suitable to sustain flight. Here we show that Helicoverpa zea males exposed to an attractive pheromone blend (and in some instances to the primary pheromone component alone) started shivering earlier and took off at a lower thoracic temperature than moths subjected to other incomplete or unattractive blends. This resulted in less time spent shivering and faster heating rates. Two interesting results emerge from these experiments. First, the rate of heat generation can be modulated by different olfactory cues. Second, males detecting the pheromone blend take off at lower thoracic temperatures than males exposed to other stimuli. The take-off temperature of these males was below that for optimal power production in the flight muscles, thus generating a trade-off between rapid departure and suboptimal flight performance. Our results shed light on thermoregulatory behaviour of unrestrained moths associated with the scramble competition for access to females and suggest ecological trade-offs between rapid flight initiation and sub-optimal flight performance.

Show MeSH
Related in: MedlinePlus