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Scent of a Dragonfly: Sex Recognition in a Polymorphic Coenagrionid.

Frati F, Piersanti S, Conti E, Rebora M, Salerno G - PLoS ONE (2015)

Bottom Line: The results of the present behavioural and electrophysiological investigations on Ischnura elegans, a polymorphic damselfly, support our hypothesis that chemical cues could be involved in Odonata sex recognition.The ability of male antennae to perceive odours from females has been confirmed by electrophysiological recordings.Behavioural studies in the field are necessary to investigate further these aspects.

View Article: PubMed Central - PubMed

Affiliation: Dipartimento di Scienze Agrarie, Alimentari e Ambientali, University of Perugia, Perugia, Italy.

ABSTRACT
In polymorphic damselflies discrimination of females from males is complex owing to the presence of androchrome and gynochrome females. To date there is no evidence that damselflies use sensory modalities other than vision (and tactile stimuli) in mate searching and sex recognition. The results of the present behavioural and electrophysiological investigations on Ischnura elegans, a polymorphic damselfly, support our hypothesis that chemical cues could be involved in Odonata sex recognition. The bioassays demonstrate that males in laboratory prefer female to male odour, while no significant difference was present in male behavior between stimuli from males and control. The bioassays suggest also some ability of males to distinguish between the two female morphs using chemical stimuli. The ability of male antennae to perceive odours from females has been confirmed by electrophysiological recordings. These findings are important not only to get insight into the chemical ecology of Odonata, and to shed light into the problem of olfaction in Paleoptera, but could be useful to clarify the controversial aspects of the mating behavior of polymorphic coenagrionids. Behavioural studies in the field are necessary to investigate further these aspects.

No MeSH data available.


One-way olfactometer response of I. elegans males raised in different social context.Number of males (% of total tested insects) reaching the sector closer to the stimulus. Males were tested towards: 1) gynochromes, 2) androchromes, 3) males (only for males raised with males), and 4) control. n = sample size. Data with different letters are significantly different at p < 0.05 (X2 test, Goodmans’ post hoc procedure)
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pone.0136697.g004: One-way olfactometer response of I. elegans males raised in different social context.Number of males (% of total tested insects) reaching the sector closer to the stimulus. Males were tested towards: 1) gynochromes, 2) androchromes, 3) males (only for males raised with males), and 4) control. n = sample size. Data with different letters are significantly different at p < 0.05 (X2 test, Goodmans’ post hoc procedure)

Mentions: Moreover, the residence time (s) of the males raised with other males in response to males (81.55 ± 32.48) and control (79.52 ± 34.57) (mean ± SE) was not significantly different (t = -0.143; df = 47; p = 0.887). In males raised either with gynochromes (Χ2 = 8.93; df = 2; p = 0.0115) or androchromes (Χ2 = 7.64; df = 2; p = 0.0230), the number of males (%) reaching the sector closer to the stimulus was significantly higher when the stimulus was represented by androchromes in comparison with the control, while it was intermediate when the stimulus was represented by gynochromes (Fig 4). In males raised with males the number of insects (%) reaching the sector closer to the stimulus was significantly higher when the stimulus was represented by androchromes in comparison with the males and the control, while it was intermediate when the stimulus was represented by gynochromes. In addition, no significant difference was shown between the responses towards the males and the control (Χ2 = 11.57; df = 3; p = 0.0090) (Fig 4).


Scent of a Dragonfly: Sex Recognition in a Polymorphic Coenagrionid.

Frati F, Piersanti S, Conti E, Rebora M, Salerno G - PLoS ONE (2015)

One-way olfactometer response of I. elegans males raised in different social context.Number of males (% of total tested insects) reaching the sector closer to the stimulus. Males were tested towards: 1) gynochromes, 2) androchromes, 3) males (only for males raised with males), and 4) control. n = sample size. Data with different letters are significantly different at p < 0.05 (X2 test, Goodmans’ post hoc procedure)
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4549108&req=5

pone.0136697.g004: One-way olfactometer response of I. elegans males raised in different social context.Number of males (% of total tested insects) reaching the sector closer to the stimulus. Males were tested towards: 1) gynochromes, 2) androchromes, 3) males (only for males raised with males), and 4) control. n = sample size. Data with different letters are significantly different at p < 0.05 (X2 test, Goodmans’ post hoc procedure)
Mentions: Moreover, the residence time (s) of the males raised with other males in response to males (81.55 ± 32.48) and control (79.52 ± 34.57) (mean ± SE) was not significantly different (t = -0.143; df = 47; p = 0.887). In males raised either with gynochromes (Χ2 = 8.93; df = 2; p = 0.0115) or androchromes (Χ2 = 7.64; df = 2; p = 0.0230), the number of males (%) reaching the sector closer to the stimulus was significantly higher when the stimulus was represented by androchromes in comparison with the control, while it was intermediate when the stimulus was represented by gynochromes (Fig 4). In males raised with males the number of insects (%) reaching the sector closer to the stimulus was significantly higher when the stimulus was represented by androchromes in comparison with the males and the control, while it was intermediate when the stimulus was represented by gynochromes. In addition, no significant difference was shown between the responses towards the males and the control (Χ2 = 11.57; df = 3; p = 0.0090) (Fig 4).

Bottom Line: The results of the present behavioural and electrophysiological investigations on Ischnura elegans, a polymorphic damselfly, support our hypothesis that chemical cues could be involved in Odonata sex recognition.The ability of male antennae to perceive odours from females has been confirmed by electrophysiological recordings.Behavioural studies in the field are necessary to investigate further these aspects.

View Article: PubMed Central - PubMed

Affiliation: Dipartimento di Scienze Agrarie, Alimentari e Ambientali, University of Perugia, Perugia, Italy.

ABSTRACT
In polymorphic damselflies discrimination of females from males is complex owing to the presence of androchrome and gynochrome females. To date there is no evidence that damselflies use sensory modalities other than vision (and tactile stimuli) in mate searching and sex recognition. The results of the present behavioural and electrophysiological investigations on Ischnura elegans, a polymorphic damselfly, support our hypothesis that chemical cues could be involved in Odonata sex recognition. The bioassays demonstrate that males in laboratory prefer female to male odour, while no significant difference was present in male behavior between stimuli from males and control. The bioassays suggest also some ability of males to distinguish between the two female morphs using chemical stimuli. The ability of male antennae to perceive odours from females has been confirmed by electrophysiological recordings. These findings are important not only to get insight into the chemical ecology of Odonata, and to shed light into the problem of olfaction in Paleoptera, but could be useful to clarify the controversial aspects of the mating behavior of polymorphic coenagrionids. Behavioural studies in the field are necessary to investigate further these aspects.

No MeSH data available.