Technology that was first used to distinguish healthy tissues from cancerous tissues in humans has been successfully used to identify insects. Every year insect pests cause massive economic damage to agriculture and forestry, either through direct attack on crops or through the transmission of diseases.
Research by the University of Liverpool in collaboration with International Pheromone Solutions (IPS), a leader in integrated pest management, could have tremendous benefits for the food industry. The technology could enable breeders and importers to identify pest insect species quickly and accurately.
The research was carried out by PhD student Iris Wagner. They used a new analytical method called Rapid Evaporative Ionization Mass Spectrometry (REIMS). REIMS is a real-time analytical method that provides a fingerprint based on the insect’s molecular composition. It involves rapid burning of the sample tissue, typically by applying an electric current to heat it (see figure below). The resulting aerosol (“smoke”) is drawn into the REIMS, creating signal patterns that are diagnostic of the species. Insect samples from different classes, e.g. B. Species 1 and Species 2 are first profiled by REIMS to train the system. Once a classification model has been created, machine learning algorithms can use it to find differences in signal patterns to identify unknown samples very quickly. Each analysis takes seconds.
Arthropod species
To prove the concept, the team of scientists first examined five arthropod species such as spiders and beetles. Once convinced of the technique, the team focused on closely related species of fruit flies (Drosophila spp.). Two of the species were closely related and their females were morphologically very similar, making typing using traditional methods such as identification using morphotaxonomic keys very difficult.
Reims could distinguish between adult and immature species, as well as male from female – all important information for producers who need to monitor and treat the infestation. This work has been described in a new scientific article entitled “The Application of Mass Spectrometry with Rapid Evaporative Ionization in the Analysis of Drosophila Species – A Potential New Tool in Entomology”.
According to Dr. Sam Jones, Technical Director for IPS, DNA analysis is currently the method of choice for identifying very similar species. The ability of REIMS to distinguish the immature stages (larvae) of many groups of insects in seconds is particularly promising. This eliminates the need to raise immaturity as a prerequisite for identification into adulthood.
Dr. Jones explains, “It’s very exciting that we have found another use for Reims. The problem that this application brilliantly overcomes is to distinguish species that are difficult to identify even by experts. We thought REIMS could be a quick alternative to PCR testing and we found it worked really well, which is a fantastic development. When you are talking about an infestation that could destroy a crop and a livelihood or a large shipping container of goods, every day becomes critical and a test that lasts seconds allows many individual insects to be analyzed.
“It is very important that we can identify pests quickly and then define a strategy. Some pests are more serious than others. If you can correctly identify one or more pests, this can aid decision-making. “
information
PhD student Iris Wagner added: “I was surprised by the quality of the information that comes out of burning an insect sample. Although complex, the learning algorithms were able to identify patterns in the data that we couldn’t see manually and create successful classification models. “Integrated pest management is based on a variety of strategies that include monitoring, information and subsequent decision-making. For example, emphasizes Dr. Jones, you should only use pesticides if the number of pests is above a certain threshold.
“When pest levels are below the threshold, natural predators should be used for plants grown outdoors. Pheromone baits are used to monitor and estimate population size. If there are more pest insects than the threshold, you can decide whether to use pesticides or a pheromone control strategy to disrupt mating. “
The next phase of the study that needs funding is to examine how the technology can be used for field use.
Dr. Jones added, “It could be very beneficial if we could use insect food (droppings) from infested plants or larvae that are particularly difficult to identify. This would be particularly useful for “quarantine pests” when imported goods are infected. Sometimes you can’t see the actual pest – just the larvae, the food and the damage. It is important to identify the presence of pests quickly before they can escape and possibly multiply – provided the environmental conditions are suitable.
Quick decisions
Quick decisions are critical to pest control. The sooner you can start pest control, the less damage there is and a few days can mean the difference between a salable or disposable crop.
“Some plants have acceptable levels of damage. If a certain level is exceeded, the buyer will refuse it or it will have to be sold for some other purpose. For example, olives need very little damage to be used as “table olives”. If rejected, they are turned into oil, which means financial losses for the farmer and the local economy. “
There have been cases where South African fruit growers were unable to sell to the EU because the level of infestation was above acceptable limits. In particular, the export of citrus fruits was stopped again in 2020. This was due to damage caused by the fake moth and the black spot on citrus (a fungal disease). Regulations in Asia and Europe tend to be very strict, especially when it comes to damage caused by pests like the fake codling moth.
Dr. Jones said, “We are trying to customize the REIMS system and have many other ideas that could help with integrated pest management.”
In certain circumstances, biological control in pest control involves maintaining the population of certain species, e.g. B. predatory insects to maintain the balance of the ecosystem. Conversely, many insects can cause significant harm, both economically and to human health.
What’s next?
IPS is looking for partners, investors and financial institutions to advance the research. If you are interested, please contact Dr. Sam Jones Sam@ips1985.co.uk.
Wirral-based IPS provides a nature-based approach and expertise for natural and safe solutions to monitor and control pests in agricultural and domestic environments.
The company’s highly qualified entomologists find solutions from nature. Together with universities, scientific partners and farmers, the IPS team works on natural solutions to reduce the use of pesticides and to support integrated pest management (IPM) in agriculture, horticulture and forestry.
A healthier, safer and more productive environment is achieved by harnessing the natural behavior of pests and finding the right pheromone combination and trapping solution for a particular species.
For more informations:
University of Liverpool
www.liverpool.ac.uk
