Don’t underestimate the power of light. Many animals can’t even survive without light. Light has significant effects on animals, such as growth, development, colouration, movement and migration, reproduction, and metabolism. It is the same with bugs. Light exists of three elements that are important: visible light, UV (sometimes) and warmth.
We already talked about light warmth in the section about ‘temperature and heating‘. In this section, we focus on light cycles and UVB light.
About light and light-cycles for bugs
For many bugs, light triggers all kind of behaviour. Bugs start to search for food, or they start reproducing. Light shows the pathway to a heat source, and heat is necessary because they are entirely depended on external heat to warm their bodies.
Bugs need appropriate light and light cycles. Most bugs will do fine with a light cycle of 12:12 hour. You can achieve this with timed switches. Most insects don’t do well in direct sunlight because of the overheating of the enclosure. So it would be best to use an artificial light source for this purpose.
If you use live plants in your enclosure, you’ll need good lighting for the plants too. Plants need a relatively high brightness of the light. For example, I use HQI lamps in the larger insect enclosure or for desert species. HQI lamps are relatively efficient light sources and produce 6x more light (lumen per watt) than that of a regular light bulb.
Unfortunately, there is not much research done on the effect of required light to keep bugs healthy.
About UVB light for bugs
There is almost no research done on the effect of UVB light for insects and many other bugs. Because bugs are kept for a long time in captivity, kept healthy for their total lifespan, and have bred successfully without the use of UVB light, we can assume that it is not that important to provide to them.
Unfortunately, that is only an assumption because there is no science-based support for this statement. Recently a study is done to see if insects can metabolize UVB to vitamin D using different levels of UVB radiation. It resulted that, apart from black soldier flies, mealworms, locusts and crickets utilize UVB into vitamin D.
But until now, we don’t necessarily need to provide UVB light, unless it is explicitly recommended for a specific species.