Asian swallowtail vision: the science and the numbers
Papilio xuthus · order Lepidoptera · Insects: all the numbers
Asian swallowtails have 5 colour channels, including ultraviolet.[1][2][3] Asian swallowtails stop seeing flicker at 107 Hz, against 60 Hz for people.[25]
- 5colour receptor classesMeasured*
- 107hertz flicker fusion (motion)Measured
The Asian swallowtail (Papilio xuthus) is an insect in the order Lepidoptera. Its eyes belong to the vision type Butterfly multispectral: four or more receptor types, including red and ultraviolet. Measured in this species: colour, night vision and motion (flicker fusion). Measured core: measured values on at least 3 of the 6 dials.
This is a simulation built from published eye measurements, not what the animal experiences.
What Asian swallowtails see: colour receptors
What stands out
- It has 5 colour receptor classes, including ultraviolet; people have 3.
- It stops seeing flicker at 107 Hz, against 60 Hz for people in this dataset, so fast motion looks about 1.8 times slower to it.[26][27]
- Activity pattern: diurnal.
The six dials
Evidence levels: how the tiers work. "Measured" means a value measured in this species; "Estimated" values come from a close relative or an eye-size formula. The last column gives the values for people from the same catalogue.
| Dial | Value | Evidence | Sources | People |
|---|---|---|---|---|
| Colour | Colour receptors 5 receptor classes: 360 nm (UVS), 400 nm (VS/SWS (violet)), 440 nm (SWS (blue)), 520 nm (MWS (green)), 600 nm (LWS (long)) measured in this species | Measured (not re-verified) | [1][2][3] | Colour receptors: 3 receptor classes: 421.5 nm (VS/SWS (violet)), 532 nm (MWS (green)), 558.4 nm (LWS (long)) Measured (not re-verified)[2][4][5][6] |
| Ultraviolet yes: at least one receptor peaks in the ultraviolet | Measured (not re-verified) | |||
| Sharpness | Acuity 0.56 cycles per degree median of 1 relatives in genus Papilio: Papilio machaon | Estimated | [7] | Acuity: 63.75 cycles per degree Measured[8][9] |
| Angle between facets 0.9° median of 1 relatives in genus Papilio: Papilio machaon | Estimated | [7] | ||
| Eye type compound eye | ||||
| Field of view | No value in the catalogue. | Binocular overlap: 122.5° Measured[10][11] Total field of view: 200° Measured (not re-verified)[12] Blind area behind the head: 160° Derived[12] Eye placement: frontal Derived[10][11] | ||
| Sharp zones (foveas) | Number of foveas 0 median of 90 relatives in class Insecta: Empis prodromus, Rhamphomyia albidiventris, Rhamphomyia breviventris, Rhamphomyia maculipennis, Rhamphomyia marginata, Rhamphomyia murina | Group default | [13] | Number of foveas: 1 Measured[14] Fovea type: fovea Measured[14] |
| Fovea type none | Group default | [13] | ||
| Night vision | Activity pattern diurnal mode of 1 rows (of 1 rows): diurnal | Measured | [2] | Activity pattern: diurnal Measured (not re-verified)[15][16][17][2][18][19][20][21] Pupil shape: vertical Group default[22][23] Reflective layer (tapetum): no Measured[24] Rods vs cones: cone-dominated Derived[15][16][17][2][18][19][20][21] |
| Rods vs cones no rods (invertebrate photoreceptors) nocturnal -> rod-dominated; crepuscular / cathemeral / mixed -> mixed; diurnal -> cone-dominated | Derived | [2] | ||
| Motion (flicker fusion) | Flicker fusion frequency 107 Hz median of 1 bright-light rows (behavioural/whole-eye ERG rows; all rows: [107.0]) | Measured | [25] | Flicker fusion frequency: 60 Hz Measured[26][27] |
All insects side by side: Insects: every measurement. Method: how we know what animals see.
Sources
- Kelber et al. 2003
- Longcore 2023
- van der Kooi CJ, Stavenga DG… 2021
- Kirwan
- Müller et al. 2009
- Thermal Activation and Photoactivation of Visual… 2004
- Caves et al. 2018
- Kirk et al. 2004
- Veilleux et al. 2014
- Heesy 2004
- Heffner et al. 1992
- Campbell & Green 1965
- Comparative data for dance fly eye…
- Kopania et al. 2025
- Anderson et al. 2017
- Borges et al. 2018
- Wilman et al. 2014
- Maor et al. 2017
- Jones et al. 2009
- Schmitz et al. 2011
- Moura et al. 2024
- Banks et al. 2015
- Cervino et al. 2021
- Guareschi et al. 2025
- Lafitte et al. 2022
- Healy et al. 2013
- Inger et al. 2014
Every value cites its sources (all sources). Values were extracted from these works and converted (units, medians, derived values); changes are ours, and the listed sources do not endorse this site. Data: catalogue-v1, built 2026-09-29. Accuracy notes: how accurate is this? Method: how we know.