discussion / Camera Traps  / 20 March 2023

Insect camera traps for phototactic insects and diurnal pollinating insects


we developed an automated camera trap for phototactic insects a few years ago and are planning on further developing our system to also assess diurnal pollinating insects, as part of a federal research project.

Does anyone have any useful tips regarding the colours that are best for attracting pollinating insects? I saw that @Max_Sitt you used blue, white and yellow "flowers" to attract insects in your system. Would you be willing to share any information on how well these colours worked for attracting different insects? I would be very grateful for your help :D


Hi Sarah,

in general yellow is probably the color which attracts the widest range of different pollinators, however there are especially many bee species who are mostly (or only) attracted by e.g. white or blue/violet.

We chose the "flower" colors and shapes for our current platform version only by trying to mimic some common flowering plants like Daucus carota, Ranunculus sp. and Cichorium intybus. From our preliminary tests last year I would say there is definitely some attraction but probably not optimised for a wider range of taxa (or specific taxa if a kind of "attraction filter" should be implemented).

Currently we are running several experiments to test different materials, colors (there are many shades of yellow...), shapes and UV reflectant properties. We are especially interested in hoverfly monitoring, so this is our target group for the tests.

@tom_august, @albags and Abra Ash are also doing research on different kinds of artifical flowers and their attraction potential (more focused on bees and bumblebees).

Hi Sarah,

I am working with @Max_Sitt on the same project to develop artificial flowers as a platform for hoverfly monitoring (also as a landing platform for his camera trap).

We have preliminary results on the attractiveness of different shapes and colors on two hoverfly species in the lab. We can not help you with useful results without fieldwork data, but maybe some ideas.

According to the literature, bees will probably go for different (structurally more complex) flowers than hoverflies. If this is the case, you won't find a highly attractive "one-fits-all" solution for the shape or any other floral characteristic. However, the color could be the most basic flower trait and, therefore, could address a variety of pollinators. With a simple structure and a universally attractive color, you might have a chance for a good trade off between attractiveness and species spectrum.

The spray colors used as standard colors for pan traps in Germany (according to C. Westphal) could be a good start for you:

Sparvar 3107 "Leuchtblau", Sparvar 3104 (aka RAL 1026) "Leuchtgelb" and Sparvar "Leuchtweiß" 3108

These strong fluorescent colours have also been tested in Diestelhorst et al. 2014 (only available in German) and they showed a good response of pollinators in general for the white and yellow color in comparison with non-fluorescent colors. If you look for publications by Klaus Lunau, you will find a lot on fluorescent colors and UV-reflectance in (artificial) flowers. But once again, there seems to be no universal pattern among all flowers and all pollinators that we can use to trigger landings.

Currently, we are experimenting with fluorescent, translucent PMMA aka Suncatchers. When we sprayed orange Suncatchers with a strong fluorescent neon yellow on the bottom side, they were very attractive to one of our tested species. Their "sun catching effect" is then visible all over the surface as a diffuse glowing.

We also had good experiences with some glass droplets that resemble nectar. Specifically a half-sphere of 5 mm diameter with mirror foliage underneath. You can get them at a DIY store.

My best guess would be to paint a platform all green and then have circles in different diameters (2-8 cm) sprayed on them with the three pan trap colors. Add some glass droplets, and you might be good for now. However, the field trials will show how much my guesses are worth here:)

Best regards,


Hi Sarah, 

I'm currently doing a PhD with @tom_august to create artificial flowers for pollinator monitoring. I'm currently looking into the key attraction cues for each broad group of diurnal pollinators. These include colour, UV, and scent and I will be performing experiments in the future to see how attractive artificial flowers can be using several different attraction cues.

Much like you already know, yellow, white and blue are good colours. A lot of insects have a preference for yellow and it is a very common generalist colour. A lot of fly species like yellow. Some insects like bees, bee-flies, and diurnal moths prefer blue. Butterflies have a preference for bright reds, oranges, and blues. It is worth having a mix of different colours if you want to attract wider variety of insects and using UV reflectance with the yellow should help as well. Like @MaximilianPink said, a green background has also shown to be effective for contrast. 

I'll be comparing the attraction of realistic 3D printed artificial flowers to coloured paper and pan traps in an experiment with naïve bumblebees soon so I can keep you updated on the results from that.  I hope in the future, if everything works, I can get a bunch of different monitoring system using my artificial flowers. 

Please let me know if you have any questions!