REDUCING THE IMPACT OF LIGHT POLLUTION ON INVERTEBRATES
WHAT'S THIS DEVICE BURIED IN THE GROUND?
It is a firefly trap that we use to assess the effect of light pollution on their intraspecific communication. Females communicate with males using light that can be mimicked. The trap is used to assess when light smog from nearby streetlights no longer interferes with firefly light communication. It is portable device based on a pitfall trap with a light lure simulating a non-flying female ready to mate, used to capture flying males. This trap is composed of two basic structural elements: a light emitter with a fluorescent layer in the spectrum of firefly bioluminescence and an opaque trapping container, secured against the escape of males by a funnel.
WHAT'S THIS DEVICE MOUNTED ON THE LAMP?
It is a device for catching nocturnal insects attracted to the light of a lamp. The light trap for invertebrate monitoring is a portable device based on a flight-interception trap. This trap is composed of two basic structural elements: a transparent plate (impact surface) and a sampling container, which is secured against leakage of the trapped invertebrates by a funnel.
WHAT ARE WE TRYING TO ACHIEVE?
The main objective of the project is to develop a methodological guideline a) usable by local authorities for the selection of suitable street lighting in order to minimize the negative impact on nocturnal insects in general and with a special focus on light-communicating species, b) enabling retrospective assessment of the impact of different types of such lighting on invertebrates. In collaboration with the Czech Technical University, we are developing standardized traps for the purpose of sampling insects for monitoring and evaluation of not only direct (attraction to light) but also indirect (interference with sexual communication) effects of artificial lighting. Based on the data collected, we will then develop standardized methodologies to evaluate the degree of influence of artificial lighting on insects, by processing the data collected using the collection methods to evaluate the direct and indirect influence of artificial lighting.
WHY DO WE DO IT?
Light pollution (LP) is one of the main environmental problems in developed countries and has a negative impact on human health and entire ecosystems. Due to the continuous development of settlements, it is one of the fastest growing threatening factors to the biodiversity of insects and other animal groups. Compared to other negative anthropogenic influences such as agricultural intensification, landscape fragmentation or climate change, this factor has been neglected for quite a long time. However, recent studies have shown that the LP can further amplify these negative effects. Nevertheless, unlike other factors, its effect can be most easily removed from the environment. From a global perspective, LP reduces insect diversity and can thus cause far-reaching negative consequences for the stability of affected ecosystems. In anthropogenic environments, it causes the creation of ecological traps. Insects are attracted to these light sources, even though they are unsuitable for them due to higher predation, lack of food or general unsuitability of the habitat. Insect attraction is strongest at shorter wavelengths (in the blue, green and UV spectrum), and the currently preferred energy-efficient LED lamps contain a significant proportion of these colours. They are therefore at the same time much more effective than older models of lights (more in the orange spectrum) in unwanted insect attraction with all the negative consequences.
Light pollution has an extremely negative effect on fireflies, who use light as a means of sexual communication and are repelled from external light sources in commonly used spectrums. In addition, in most of Europe there are species that form only local populations with little mobility due to flightless females, and new sources of LP are thus capable of causing the extinction of these populations within a single generation.
