“…semiochemicals are not poisonous or lethal. Their function is to interrupt the mating process of pests…”
Paulo Rivara is the sales operations manager at Suterra in Chile, and an agronomist from the University of Talca.
Paulo Rivara, manager at Suterra
AgriBrasilis – What is pest control through mating interruption?
Paulo Rivara – It is a strategy used to reduce the population of harmful insects in crops in a more sustainable and environmentally correct way.
Pheromones are chemicals that insects release into the air to attract individuals of the opposite sex during the mating process. When the adult female is in the reproductive phase, she releases a chemical signal that allows distant male insects to find her and reproduce.
The mating interruption technique consists of interfering with this communication, saturating areas of the farms with synthetic pheromones, that mimic the female’s sexual pheromones. These products confuse male insects and divert them from real females, preventing the pests from reproducing.
AgriBrasilis – What is the market for semiochemicals in Chile? For which crops and pests are these products intended?
Paulo Rivara – The semiochemicals market in Chile is focused on mating interruption pheromones and baits for traps used to monitor pests.
The market of greatest interest is that of mating interruption pheromones for the pest Lobesia botrana [vine moth]. This pest is under mandatory official government control protocol, supervised by the Agricultural Service of Chile. It attacks vine crops (table and wine grapes), plums and blueberries.
Lobesia botrana
Second are products based on mating interruption pheromones used to control the Cydia pomonella moth in pomegranates and walnut trees, and the oriental fruit moth (Cydia molesta) in stone fruit farming.
Thirdly, there are also some control alternatives for other pests in vegetables and fruit plants.
AgriBrasilis – How do semiochemicals compare to conventional insecticides? Can this alternative completely replace insecticides?
Paulo Rivara – Unlike conventional insecticides, that are generally toxic compounds designed to directly kill or control insects, semiochemicals are not poisonous or lethal. Their function is to interrupt the mating process of pests.
As for the action mode, conventional insecticides usually have a contact or ingestion effect, killing insects as soon as they come into contact with the product or ingest it, while semiochemicals act by confusing or interrupting the mating behavior of insects.
Another important difference is selectivity. Conventional insecticides, being more aggressive, can have a negative impact on non-target organisms, such as beneficial insects, pollinators or natural predators of pests. In contrast, semiochemicals are more specific and selective, primarily targeting target species and minimizing impact on other organisms.
Cydia pomonella
Conventional insecticides can generate loss of sensitivity or resistance in pest populations over time, that reduces the effectiveness of control. In the case of pheromones for mating interruption, this practice does not exert selective pressure for the development of resistance, since it does not directly affect the survival of the pests.
Both semiochemicals and conventional insecticides have their place in integrated pest management. Depending on the context and characteristics of the pest in question, different approaches can be combined to achieve effective and sustainable control.
AgriBrasilis – In Chile, the law requires biological control using semiochemicals in vineyards. Why did this happen? What are the benefits of this legislation?
Paulo Rivara – Mandatory control using semiochemicals is specific to the pest Lobesia botrana. This pest is quarantined for many markets that are export destinations for fruits from Chile.
Lobesia botrana was detected for the first time in Chile in 2008, in the Linderos area, in the Metropolitan Region. The pest, originally from Europe, attacks the country’s vineyards. Its larva causes direct damage, feeding on bunches of grapes, causing rot, dehydration of the berries, and a great reduction in productivity.
In the case of table grapes, the presence of this pest is a condition for immediate rejection by buyers, especially in destinations where the insect is absent (USA and China, for example).
After a few years trying to control this moth using only chemical control, in 2016/17 the health authorities decided to use semiochemicals as a mandatory control standard. Through this eradication plan, populations of this pest have remained low.
AgriBrasilis – How did the high temperatures in the country affect the population of pests?
Paulo Rivara – High temperatures can significantly impact pest populations. The relationship between high temperatures and the population of lepidopterans (the group that the pest Lobesia botrana belongs to) is complex and depends on several factors, such as the species present in crops and specific environmental conditions.
In general, high temperatures can accelerate the development and life cycle of lepidopterans. This is because they are ectothermic, that means that their body temperature is influenced by the ambient temperature. Higher temperatures accelerate the metabolism of these insects, that can increase the rate of larval development, pupation and emergence of adults.
Life cycle acceleration can have several implications for population dynamics. Under favorable conditions, Lepidoptera populations can increase rapidly because of a higher reproductive rate and overlapping generations. This may result in an increase in the number of individuals and increase of pest pressure on farms.
High temperatures can also have negative effects on lepidopteran populations. Extremely high temperatures can cause dehydration, reduce the availability of food resources and increase the mortality of larvae and adults. Furthermore, temperatures that are too high can interrupt the synchronization between lepidopteran phenology and the availability of their food sources, that negatively affects their survival and reproduction.
Some species may be more tolerant of warmer weather and show more favorable responses, while others may be more sensitive.
AgriBrasilis – What is Suterra’s role in Chile and Latin America?
Paulo Rivara – Suterra has a long history of presence in Latin America. In the last two years we have had significant growth in new products in the company’s portfolio and in the number of partners and farmers who use our products.
Our sexual confusion systems are in countries like Peru and Colombia, that still had no tradition of using this sustainable technique. We have operations in Argentina, Chile, Uruguay and Mexico. Soon we intend to expand to other countries.
Our focus has been on stone fruits, both in Chile and Argentina, but in recent years we have started to act on grape farms (table and wine) and we are also working with citrus fruit crops, blueberries, etc.
AgriBrasilis – What are puffer aerosol systems? How do they differ from other semiochemical diffusion technologies?
Paulo Rivara – Suterra is a company that stands out in terms of innovation. We have advanced in different pheromone emission platforms. Currently, we have three types: sprayable pheromones, passive diffusers, and patented Puffer branded active aerosol diffusers.
Puffers are electromechanical devices capable of releasing pheromones into the environment, in a controlled and uniform manner, throughout the entire harvest. This device is not affected by environmental conditions, that allows a rational and effective use of the pheromone. They are devices programmed to spray the products during the period of greatest activity of the pests.
The Puffer is able to emit a stable and homogeneous concentration of pheromone in a certain time interval, without interruption, and during the entire period of flight of the pests.
This technology allows a very low number of emitters to control a large area: with just two units we can cover approximately 10,000 m2. This low number of emitters facilitates quick installation in the orchard, that reduces labor and operating costs.
READ MORE:
“It is a Mistake to Compare Biological and Chemical Pesticides”