Olfactory learning in Pieris brassicae butterflies is dependent on the intensity of a plant-derived oviposition cue
Data files
Mar 12, 2024 version files 226.82 KB
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GHdata_dp.xlsx
56.49 KB
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OUTdata_dp.xlsx
50.93 KB
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pierislegtaste.xlsx
31.14 KB
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README.md
5.04 KB
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workingdataGH.xlsx
43.25 KB
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workingdataOUT.xlsx
39.97 KB
Jul 26, 2024 version files 123.15 KB
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GHdata.xlsx
64.10 KB
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OUTdata.xlsx
47.69 KB
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pierislegtaste.csv
6.15 KB
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README.md
5.20 KB
Abstract
Butterflies, like many insects, use gustatory and olfactory cues innately to assess the suitability of an oviposition site and are able to associate colours and leaf shapes with an oviposition reward. Studies on other insects have demonstrated that the quality of the reward is a crucial factor in forming associative memory. We set out to investigate whether the large cabbage white Pieris brassicae (Linnaeus) has the ability to associate an oviposition experience with a neutral olfactory cue. In addition, we tested whether the strength of this association is dependent on the gustatory response to the glucosinolate sinigrin, which is a known oviposition stimulus for P. brassicae. Female butterflies were able to associate a neutral odour with an oviposition experience after a single oviposition experience, both in a greenhouse and in a semi-natural outdoor setting. Moreover, butterflies performed best when trained with concentrations of sinigrin that showed the strongest response by specific gustatory neurons on the forelegs. Our study provides novel insight into the role of both gustatory and olfactory cues during oviposition learning in lepidopterans and contributes to a better understanding of how these insects might be able to adapt to a rapidly changing environment.
Folder structure and contents:
These files are related to the behavioural observations in both indoor and outdoor settings:
- GHdata.xlsx
- OUTdata.xlsx
- GH_Sinigrin_Behaviour.R
- OUT_Sinigrin_Behaviour.R
- Peftuloglu_et_al_Electronic_Supplementary_Material.pdf
These files are related to the electrophysiological taste recordings performed:
- pierislegtaste.csv
- Pierislegtaste script.R
Pieris_ovi.mp4: Mp4 video of oviposition instance by a female Pieris brassicae on green paper disc impregnated with sinigrin.
Peftuloglu_et_al_Electronic_Supplementary_Material.pdf: This file contains a picture of the indoor set-up, as well as graphs showing the proportion of time spent on vanilla-scented vs. unscented discs for control butterflies as well as butterflies trained with different concentrations of sinigrin in the indoor trails (figure S1). The file also contains images of the outdoor set-up and graphs showing the proportion of time spent on vanilla-scented vs. unscented discs for control butterflies as well as butterflies trained with different concentrations of sinigrin in the outdoor trails (figure S2). Finally, the file provides additional statistical results for the time spent and the number of visitations to scented and unscented discs in the indoor and outdoor set-up by both trained and untrained butterflies (table 1-4).
MEASUREMENTS IN “GHdata” and “OUTdata”:
- Consolidation: time (expressed in minutes) used to consolidate memory formation after conditioning.
- Testing time: length (expressed in minutes) of the behavioural observation.
- Flight: binary expression (1 or 0) to express whether flight (i.e., behavioural response) occurred.
- Training: used to express whether the tested animal was conditioned or naive (i.e. control)
- ConcentrationTraining: milli molar concentration value of the unconditioned stimulus used during
training. - EggsTraining: number of eggs laid during the training event by the conditioned animal.
- TimeScentedDiscs: time spent on vanilla-scented discs during testing, expressed in seconds.
- TimeControlDiscs: time spent on control discs during testing, expressed in seconds.
- Total time: sum of the time spent on both disc classes, expressed in seconds.
- PercentScent: percentage of the time spent on vanilla-scented discs in Total time.
- PercentControl: percentage of the time spent on control scented discs on Total time.
- PrefIndexTime: preference index for time spent on vanilla scented discs, calculated as:
(TimeScentedDiscs)-(TimeControlDiscs)/(TotalTime) - TotalTrial: time spent on vanilla scented discs during the total trial, calculated as TimeScentedDiscs/1800
- TotalTrialC: time spent on control discs during the total trial, calculated as TimeControlDiscs/1800
- VisitsScent: total number of visits (i.e. approaches) to vanilla-scented discs during testing.
- VisitsControl: total number of visits (i.e. approaches) to control discs during testing.
- TotalVisits: sum of VisitsScent and VisitsControl.
- EggsScentedDiscs: number of eggs laid on vanilla-scented discs during testing if oviposition occurred.
- EggsScented: binary value (1 or 0) that expresses whether oviposition on vanilla-scented discs occurred during testing.
- EggsControlDiscs: number of eggs laid on control discs during testing if oviposition occurred.
- EggsControl: binary value (1 or 0) that expresses whether oviposition on control discs occurred during testing.
- T: temperature measured in Celsius degrees at the beginning of each test.
- rH: percent relative humidity (for outdoor observations only).
- Wind: windspeed in m/s (for outdoor observations only).
- Pressure: pressure value measured in millibars at the beginning of each test (hPa).
- Lux: light intensity (lx) measured at the beginning of each test.
- Notes: additional remarks.
- Empty cells indicate missing values.
MEASUREMENTS IN “Pierislegtaste”:
- ID: numerical value used to identify an animal used for a complete electrophysiological recording round.
- Animal: numerical value used to identify recordings within a single day (not used in analysis).
- Sensillum: identifies the sensillum type implied with the recording, namely “medial” or “lateral”.
- Spikes_large: number of spikes with amplitude greater than 1 mV during the 1st second after stimulus onset.
- Spikes_medium: number of spikes with amplitude between 0.5 and 1 mV during the 1st second after stimulus onset.
- Spikes_small: - Spikes_large: number of spikes with amplitude smaller than 0.5 mV during the 1st second after stimulus onset.
Not used in analysis since not easily distinguishable from recording artifacts. - Empty cells indicate missing values.
Version changes:
26-July-2024: A new version of “Peftuloglu_et_al_Electronic_Supplementary_Material.pdf” was added including updated supplementary statistical results tables.
Software Required:
- R 4.3.1
- Rstudio 2023.12.1
Contact: dimitri.peftuloglu@wur.nl, alexander.haverkamp@wur.nl
Butterflies were conditioned by spraying 1 ml sinigrin solution on a green paper disc (9.5 cm in diameter) as an unconditioned stimulus, coupled with 20 microliters of vanilla scent as a conditioned stimulus. Three different concentrations of sinigrin solution were used. 3 different conditioning treatments plus one group of non-conditioned naive animals --> four different treatments. Tests consisted of releasing one animal in a testing environment provided with four green paper discs, identical to the ones used during training, but without sinigrin. Two of these were scented with vanilla scent, while the other two were scented with 30% alcohol-water solution. Each test lasted 30 minutes. Parameters recorded for each test are listed and explained below. Please note that not all of the recorded parameters have been used for analysis.
Electrophysiology
Response of the trichoid taste sensilla to sinigrin was assessed with single sensillum recordings. Sinigrin was dissolved in 1 mM KCl, 4 different concentrations were used (1, 10, 20, 30 mM), while 1 mM KCl was used as blank control. The foretarsi of female Pieris brassicae present two different sensilla classes, namely medial and lateral, with two clusters for each class. One random sensillum for each class was screened for responses to sinigrin.