Practice Abstract - Research and innovation

How do laser beams affect beetles?

How do laser beams affect beetles?

Beetles
Beetles belong to the order Coleoptera and are insects characterized by having their front pair of wings hardened into wing cases. There are about 400,000 beetles described, and Coleoptera is the largest of all orders, constituting almost 40% of described insects and 25% of all known animal species. Beetles are found virtually in every habitat. Beetles often feed on fungi and plants and break down plant debris and animals. Some beetles are agricultural pests, while others are beneficial insects (e.g., ladybirds or ladybugs) eating plant-sucking insects like trips and aphids that damage crops. The Tenebrio molitor beetle, is a large one reaching 25 mm in length. It has often been used as a test insect in ecotoxicological studies as it is easy to propagate, feed and keep indoors in laboratories.
We exposed T. molitor beetles to increasing dosages of laser energy (Joule) from a collimated thulium-doped 2 µm 50 W fiber laser with a 2 mm beam diameter. Afterward, we recorded the number of dead beetles 8 and 15 days after treatment.
 
Results and Conclusion
The mortality of the beetles increased with increasing dosages. All beetles were dead after 15 days when exposed to a dose of 25 J appropriate to kill weed seedlings (see figure). At low dosages, the mortality increased between 8 and 15 days after treatment, while the beetles almost immediately died at the highest dosages. The T. molitor beetle is a big one with wings hardened into thick wing cases. Therefore, it is likely that smaller beetles that are less protected would be more sensitive to laser irradiation (see Practice Abstract 43). However, only a tiny part of the total field (less than 1%) will be exposed to the laser treatment, even with a high weed density in the field. Therefore, the probability of hitting a beetle with the laser beam is low.
Beetles
Beetles belong to the order Coleoptera and are insects characterized by having their front pair of wings hardened into wing cases. There are about 400,000 beetles described, and Coleoptera is the largest of all orders, constituting almost 40% of described insects and 25% of all known animal species. Beetles are found virtually in every habitat. Beetles often feed on fungi and plants and break down plant debris and animals. Some beetles are agricultural pests, while others are beneficial insects (e.g., ladybirds or ladybugs) eating plant-sucking insects like trips and aphids that damage crops. The Tenebrio molitor beetle, is a large one reaching 25 mm in length. It has often been used as a test insect in ecotoxicological studies as it is easy to propagate, feed and keep indoors in laboratories.
We exposed T. molitor beetles to increasing dosages of laser energy (Joule) from a collimated thulium-doped 2 µm 50 W fiber laser with a 2 mm beam diameter. Afterward, we recorded the number of dead beetles 8 and 15 days after treatment.
 
Results and Conclusion
The mortality of the beetles increased with increasing dosages. All beetles were dead after 15 days when exposed to a dose of 25 J appropriate to kill weed seedlings (see figure). At low dosages, the mortality increased between 8 and 15 days after treatment, while the beetles almost immediately died at the highest dosages. The T. molitor beetle is a big one with wings hardened into thick wing cases. Therefore, it is likely that smaller beetles that are less protected would be more sensitive to laser irradiation (see Practice Abstract 43). However, only a tiny part of the total field (less than 1%) will be exposed to the laser treatment, even with a high weed density in the field. Therefore, the probability of hitting a beetle with the laser beam is low.
Source Project
WeLASER-SUSTAINABLE WEED MANAGEMENT IN AGRICULTURE WITH LASER-BASED AUTONOMOUS TOOLS
Ongoing | 2020-2023
Main funding source
Horizon 2020 (EU Research and Innovation Programme)
Geographical location
Spain
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