How does the American cockroach see?
The American cockroach (Periplaneta americana) is a insect in the order Blattodea. Its eyes belong to the vision type Fast fly (slow-motion world).
Measured in this species: colour, sharpness, night vision and motion (flicker fusion). Measured core: measured values on at least 3 of the 6 dials. Every value below carries its evidence level and sources; nothing is typed by hand.
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What stands out
- It has two colour receptor classes (a dichromat): reds and greens fall on one axis, as in red-green colour blindness in people.
- Its sharpest vision resolves 0.21 cycles per degree: the finest stripe pattern it can tell apart from grey.
- It stops seeing flicker at 42.1 Hz, against 60 Hz for people in this dataset, so fast motion looks choppier to it.[7][5]
- Activity pattern: nocturnal.
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.
| Dial | Value | Evidence | Sources |
|---|---|---|---|
| Colour | Colour receptors 2 receptor classes: 365 nm (UVS), 507 nm (MWS (green)) measured in this species | Measured | [1] |
| Ultraviolet yes: at least one receptor peaks in the ultraviolet | Measured | ||
| Sharpness | Acuity 0.21 cycles per degree median of 1 optical rows (method priority rule); acuity_cpd: dim-light rows (bright-light rows used) set aside (labelled alternative: 0.23, 0.43); interommatidial_angle_deg: dim-light rows (bright-light rows used) set… | Measured | [2] |
| Angle between facets 2.4° minimum (acute-zone) interommatidial angle over sources; within caves2018: minimum (round-1 rule: mean of horizontal and vertical when both exist); interommatidial_angle_deg: dim-light rows (bright-light rows used) set… | Measured | [2] | |
| Eye type compound eye | |||
| Field of view | No value in the catalogue. | ||
| Sharp zones (foveas) | Number of foveas 0 median of 91 relatives in class Insecta: Empis prodromus, Rhamphomyia albidiventris, Rhamphomyia breviventris, Rhamphomyia maculipennis, Rhamphomyia marginata, Rhamphomyia murina | Group default | [3] |
| Fovea type none | Group default | [3] | |
| Night vision | Activity pattern nocturnal mode of 1 rows (of 1 rows): nocturnal | Measured | [4] |
| Rods vs cones no rods (invertebrate photoreceptors) nocturnal -> rod-dominated; crepuscular / cathemeral / mixed -> mixed; diurnal -> cone-dominated | Derived | [4] | |
| Motion (flicker fusion) | Flicker fusion frequency 42.1 Hz median of 2 rows (no bright-light flag) (behavioural/whole-eye ERG rows; all rows: [41.8, 42.5]) | Measured | [5][6] |
Related animals
- Fruit fly (Drosophila melanogaster) same vision type
- Housefly same vision type
- Blowfly (Calliphora vicina) same vision type
- Tsetse fly (Glossina pallidipes) same vision type
- Yellow fever mosquito same vision type
- Blowfly (Calliphora collini) same vision type
More insects: all insects with measured vision data.
Sources
- van der Kooi CJ, Stavenga DG, Arikawa K, Belusic G, Kelber A. 2021. Evolution of insect color vision: from spectral sensitivity to visual ecology. Annu Rev Entomol 66:435-461. Supplementary table. doi.org/10.1146/annurev-ento-061720-071644
- Caves EM, Brandley NC, Johnsen S (2018) Visual acuity and the evolution of signals. Trends Ecol Evol 33:358-372. Supplementary Tables S1-S3.. doi.org/10.1016/j.tree.2018.03.001
- Comparative data for dance fly eye morphology and female ornamentation (Empididae). Data: Dryad doi:10.5061/dryad.rr4xgxd5z. doi.org/10.5061/dryad.rr4xgxd5z
- Longcore T. 2023. A compendium of photopigment peak sensitivities and visual spectral response curves of terrestrial wildlife to guide design of outdoor nighttime lighting. Basic Appl Ecol 73:40-50. doi:10.1016/j.baae.2023.09.002. doi.org/10.5281/zenodo.8432720
- Inger R, Bennie J, Davies TW, Gaston KJ. 2014. Potential biological and ecological effects of flickering artificial light. PLoS ONE 9(5): e98631. Table 3. doi.org/10.1371/journal.pone.0098631
- Lafitte A, Sordello R, Legrand M, Nicolas V, Obein G, Reyjol Y. 2022. A flashing light may not be that flashy: A systematic review on critical fusion frequencies. PLoS ONE 17(12): e0279718. S10 File (CFF database). doi.org/10.1371/journal.pone.0279718
- Healy K, McNally L, Ruxton GD, Cooper N, Jackson AL. 2013. Metabolic rate and body size are linked with perception of temporal information. Animal Behaviour 86:685-696. Table 1. doi.org/10.1016/j.anbehav.2013.06.018
Every value cites its sources (all sources). Data: catalogue-v1, built 2026-09-29. Accuracy notes: how accurate is this?