- A special issue of the Journal of Economic Entomology in June focuses on the potential for the use of drones in a variety of ways for pest control.
- A special issue of the Journal of Economic Entomology in June focuses on the potential for the use of drones in a variety of ways for pest control.
- Proponents of the strategy believe that providing bio-control resources through drones can be used to reduce or in some cases replace the use of pesticides so that growers can take advantage of the higher prices for organic produce.
- Strict airspace regulations, limited payload capacity, and high take-off costs are some of the speed bumps for the widespread use of drones in agriculture, but experts remain optimistic that drone-based pest control strategies will become more common in the years to come.
In some places in North America, the buzzing over fields and forests may no longer predict problems, but rather an innovative solution to a centuries-old problem.
Drones are gaining in importance as a method of combating insect pests in agriculture. Insect damage to crops costs more than $ 100 billion a year in the United States alone. Instead of just supplying pesticides, researchers and drone technologists are using the machines to create something new: more bugs. A special collection, published this June in the Entomological Society of America’s Journal of Economic Entomology, highlights the potential of drones to aid pest control strategies that can also reduce the use of agrochemicals.
Researchers are testing drones to throw off natural enemies of insect pests, in addition to conventional treatments like mating disruptors or insecticides. The natural enemies known as biological controls or “bio-controls” use natural mechanisms such as predation to remove plant pests. For example, a group in Canada tested drones as a means of laying the eggs of parasitic wasps (Trichogramma spp.) To control pests that infest corn fields and mixed spruce forests in Quebec. The wasps hatch, mature and lay their own eggs in those of the pests.
Researcher Véronique Martel has spent much of her career studying wasp biocontrols in agricultural settings. Breeders typically distribute wasp eggs via costly manned airplane flights or by placing them manually on the ground. Martel from the Canadian Department of Natural Resources wanted to see how biological wasp controls would work in a forest setting.
She initially experienced a backlash from colleagues who thought the strategy was unrealistic. However, the introduction of new technologies changed the calculus.
“When I heard that they tested [drone delivery] I wanted to do it in agriculture [in forests]“Martel said to Mongabay. “I was jealous.”
Martel and her group have teamed up with the Canadian company Canopée to deploy paratrooper parasitoids from specially equipped drones. Their study showed that the drones were just as effective as the manual method in forest settings, meaning the technology could be used to treat larger areas than would be within walking distance.
Researchers and drone technologists use drones to throw off insects such as parasitic wasps, which are natural enemies of insect pests.
Drones could replace the use of pesticides
Organic controls are neither new nor unusual in the world of agriculture. According to Michael Brewer, associate editor of the Journal of Economic Entomology, the move away from bio-controls began when DDT and other pesticides became more common after World War II.
“The nice thing about insecticides is that you can put them in a bottle, right?” Said Brauer. He said that while insecticides have the advantage of being easy to use, they can harm the environment.
However, he noted that biological control methods may not work in every case, for example against insects with large, established populations. In these cases, targeted application of insecticides may be the best option for the grower.
“In order not to keep spraying everything, the few people out there who do pest control need more eyes. This is where imaging drones come in, ”Brewer said.
Depending on the camera on board, a drone can take color, heat or even hyperspectral images. Imaging drones are widely used in conservation today to monitor wildlife and locate rare plants, but they have not yet found a permanent place in agricultural pest control.
Imaging drones help farmers to identify pest infestation at an early stage and to only apply insecticides in affected areas. Image courtesy of M3 Agriculture Technologies.
A drone that carries insects to be released over agricultural land. Image courtesy of Véronique Martel.
The use of imaging drones enables farmers to detect pest infestation at an early stage and to apply insecticides only to affected areas. For example, one of the studies published in the Journal of Economic Entomology used drone images to find the nests of the oriental moth (Monema flavescens), an invasive species that infests trees and fruit trees in the urban landscape.
Canopée began providing drone imagery to landowners, but quickly shifted its focus to interventions. Canopée vice president Frédéric Jean said the technology behind using drones to provide bio-controls isn’t ready for commercial use – but it won’t be long.
“We’re on the threshold,” he said. “No one on their feet could be anywhere near as efficient [as drones]. “
Nathan Moses-Gonzales, CEO of M3 Agriculture Technologies, made a similar statement. He says the breeders are eager to apply the new technology.
“I think there’s some sort of perspective that farmers don’t really look at data. They don’t really think about machines, ”Moses-Gonzales told Mongabay. “But it’s just the opposite.”
Moses-Gonzales, a trained technologist, worked with the United States Department of Agriculture (USDA) to control the Mexican fruit fly (Anastrepha ludens), an invasive and economically harmful agricultural pest that has been documented in Arizona, California, and Texas.
Researcher Hugh Conway poses with the sterile fruit flies they used to control the fruit fly population. Image courtesy of M3 Agriculture Technologies.
The group tested the use of automation to generate swarms of drones in which multiple rotary wing drones are flown at the same time. Moses-Gonzales and his team tested their strategy with groups of three or four coffee table-sized drones, but they flew up to 12 drones at a time. The machines are activated by a controller and sent on specified routes, either simultaneously or in waves.
“The whole thing looks just crazy in my opinion,” he said. “They sound a bit like a swarm of bees.”
The drones delivered sterile fruit flies to citrus groves along the Rio Grande, where they brooded with wild individuals but did not produce offspring, resulting in a significant population decline. Typically, similar strategies would be implemented using ATVs or human-controlled aircraft.
According to Moses-Gonzales, techniques like these can help farmers as public interest in organic produce grows.
“People are really starting to think more about what they’re putting into their bodies,” he told Mongabay.
A drone that releases bio-controls. According to Moses-Gonzales, techniques like these can help farmers as public interest in organic produce grows. Image courtesy of Véronique Martel.
On the threshold – but restrictions remain
While growers may make higher profits from lower pest damage and higher prices for organic produce protected by drone-based bio-control techniques, cost can still be a limiting factor. The upfront investments associated with buying or renting drones can still be prohibitively expensive for some. Even so, it’s already cheaper than manned aircraft and less labor-intensive than ground-based strategies.
In addition, there are some significant restrictions that could slow the rise of this still relatively niche area of the agricultural engineering industry. Studies are still needed to assess how drones can be used most effectively: methods proven from the ground may need to be adapted if deployed from the air.
The drones themselves also have room for improvement. Frequently mentioned problems are the limited weight capacity and the battery life. While today’s drones are efficient in the air, they can only carry limited weight and travel that far before having to return to the launch site.
“We have to invest the money in a drone that is big enough for you to cover a large enough field … but you have to have an operating license under these circumstances,” said Jean from Canopée.
While profits will increase from lower pest infestation and higher prices for organic produce protected by drone-based bio-control techniques, costs can still be a limiting factor. Image courtesy of Véronique Martel.
Strict regulations in the US and Canada pose a constant challenge to the use of commercial drone technologies. One of the most limiting factors, according to the experts surveyed, is the difficulty of being able to fly drones out of line of sight, which discourages the development of larger drones that fly further could carry heavier payloads.
Still, M3 Agriculture Technologies and Canopée say that as technology advances and government bureaucracy removed, they expect growth in agricultural applications for drones.
“The sky is the limit,” said Moses-Gonzales.
Quotes:
Moses-Gonzales, N., Conway, H., Krompetz, D., Rodriguez, R., Adams, CG, Baez, I. & Milam, M. (2021). The use of several unmanned aircraft systems as a swarm to release sterile Mexican fruit flies (Diptera: Tephritidae) in South Texas citrus groves. Journal of Economic Entomology. doi: 10.1093 / jee / toab024
Moses-Gonzales, N., & Brewer, MJ (2021). A special collection: drones to improve pest control. Journal of Economic Entomology. doi: 10.1093 / jee / toab081
Martel, V., Johns, RC, Jochems-Tanguay, L., Jean, F., Maltais, A., Trudeau, S.,… Boisclair, J. (2021). The use of UAS to release the egg parasitoid Trichogramma spp. (Hymenoptera: Trichogrammatidae) against an agricultural and forestry pest in Canada. Journal of Economic Entomology. doi: 10.1093 / jee / toaa325
Park, Y., Cho, JR, Lee, G. & Seo, BY (2021). Detection of Monema flavescens (Lepidoptera: Limacodidae) cocoons with small unmanned aircraft systems. Journal of Economic Entomology. doi: 10.1093 / jee / toab060
Banner image by researchers with a Véronique Martel drone.
Agriculture, Agrochemicals, Agroecology, Conservation, Conservation Technology, Drones, Environment, Insects, Pesticides, Science, Technology, Technology Development, Wildtech
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