With The Efforts Of A Group Of Scientists, It Has Become Possible To Mass Produce Pheromones That Prevent The Reproduction Of Insects Near Agricultural Products.

The cotton bollworm, which is a cream color and is only a few centimeters long, is not very attractive; But this lively moth has annoyed farmers worldwide. They don’t just eat the cotton crop; They also attack soybeans, tomatoes, sweet corn, peppers, and many other crops, eating flowers, reproductive tissues, fruits, and kernels. They can destroy the entire crop quickly. Females can lay hundreds of eggs, from which insatiable cocoon-making worms emerge.

Every year, insects like cotton bollworms destroy more than 20% of crops worldwide. Farmers fight them by using pesticides, But some pesticides are dangerous for human health, and many harm the surrounding ecosystems. In this situation, it is clear that we need more environmentally friendly approaches to pest control, and one of the solutions can be targeting the sexual instinct of these pests.

Female insects can attract male insects in total darkness without any audio signal and from hundreds of meters and sometimes more than one kilometer, using sex pheromones. Males follow the scent of these chemical signals and mate with females that reach them. The females then lay eggs that hatch into hungry larvae. This chemical power is fantastic and can be harnessed for your purposes. Hong Li Wang, a researcher in the pheromone group at Lund University in Sweden, says:

We can use synthetic pheromone compounds in the field that are released into the air and mask the primary signal of female insects.

Masking the sex odor makes it harder for the male insect to find and mate with female insects, Wang explains. Therefore, the population of the considered insect decreases; This means that there will be fewer pests in that area to damage the crops. Farmers have been using artificial pheromones this way for decades, But until now, the costs have prevented their widespread use. The production of synthetic pheromones has been costly; Therefore, their use has only been logical for protecting high-value products such as fruits.

Now, Wang and his colleagues have discovered a way to cost-effectively and sustainably produce pheromones that attract pests that destroy cheaper crops such as cabbage and beans, paving the way for the broader use of pheromones for pest control. In a paper published in Nature Sustainability, the group showed how to produce significant amounts of two essential insect pheromones from the oilseed plant Camelina sativa.

Next, they showed that the synthetic pheromones worked well in mass predation experiments and disrupted cotton bollworm mating: Christer Lofstedt, one of the study’s authors and professor of applied zoology at Lund University.

The first thing we had to do was to determine the pathways of pheromone production in insects.

Lofstedt’s group examined the genes of insects to find the genes that control the production of the desired sex pheromone. Then, the researchers inserted these genes into a different biological substrate to produce a large amount of sex pheromone (this study used the linseed plant), although yeast was also effective.

Finally, the intended compound was isolated and purified to be prepared for field testing. New plant-derived pheromones were tested using pheromone diffusers, and their efficacy was compared with conventional synthetic pheromones. Both versions were equally effective in trapping insects and disrupting their mating.

The effectiveness of artificial pheromones was shown in the form of a decrease in the population of male insects over time. These results proved that plant-derived pheromones could be a suitable alternative to synthetic pheromones commonly used. Establishing that the new method of pheromone production is efficient and effective has taken about a decade. Lovett says:

Now we are looking to increase the scale of this process and supply it to the market.

Ofsted’s research paves the way for sexual disruption to protect other crops against nebs pests. Lovett says:

It should be possible to use pheromones in sugarcane and soybean production.

The beauty of pheromones is that they do not kill insects and only affect their behavior. This makes them more environmentally friendly than pesticides, which often kill many non-target species, explains Srinivasan Ramasamy, an entomologist at the World Vegetable Center.

Pesticides are commonly found in soil, air, water, and on non-target organisms in our ecosystems. They can harm plants and animals, ranging from soil microorganisms and beneficial insects such as bees and pollinators to spiders and mites and plants, fish, birds, and other forms of wildlife.

Specificity is one of the most apparent features of the pheromone system. Also, insects recognize whether or not a particular pheromone signal is of their species. This means you can target the life cycle of specific pests; while not affecting other insects. Wang says:

 

This system is suitable not only for many insects in that environment but also for farmers and consumers. Insect pheromones are not toxic to humans, which is a real advantage for farm workers. Lofted explains:

Conventional insecticides negatively affect the fertility of farm workers.

Some pesticides target insect body systems that have physiological similarities to humans, Like neurotransmitters. Ramasamy says:

When you are exposed to these pesticides, they can affect your physiology.

More importantly, Lofted says, insects do not develop resistance to their communication signals, While they become resistant to pesticides.

Even if this technique scales, there will be limits to how it can be used. Repeated use of a family of pesticides usually results in the insects adapting and no longer reacting to the same chemicals; Therefore, to see their effect, we need to apply more significant amounts, which have dire environmental consequences. In this case, cooperation between neighboring farmers is also essential; Because mating disruption works better if a larger area is considered. Female pests may mate outside fields and then travel and lay eggs elsewhere. Lovett says:

Usually, using pheromones to control insects in the home garden is not very successful.

SomRamasamy cautions that the fact that the synthetic pheromones produced in the manner described are genetically modified (GMO) products can be a significant obstacle and increase costs. Lofstedt says strict rules on using GMOs in Europe could mean that Europe loses these crops. Some regulations must be followed. Finally, there are biological limits to how many pheromones can be used. They are not the right choice for all pests. Lofted explains:

Not all insects have sex pheromones.

Some insects produce complex compounds that are not easy to bioengineer. In some cases, the sex pheromone consists of two or three compounds. Ramasamy says:

In that case, you need two or three genetically engineered plants, all of which must be able to pass the regulations.

The reality is that for agricultural sustainability, we may need a combination of pest control techniques, Such as pesticides made from fungi or viruses and pest-resistant plant varieties used alongside engineered pheromones. However, competition for pest control is now fierce: pesticides are readily available, easy to use, target multiple insects, and are relatively inexpensive. Ramasamy says:

If the integrated pest management program includes five different components, farmers will not agree to it.

According to him, the key to this problem is to find a solution that is stable and, at the same time, simple.

However, Ofsted believes that plant-produced pheromones could be a big part of the pest control approach in the future. It’s green chemistry, he says, driven by solar energy; Therefore, if we want to act sustainably and protect wildlife, crops, and human health, we need to find pest control methods like this that can scale up to reduce pesticide use.