University of TyumenGetting to the root of pest control

Getting to the root of pest control


The University of Tyumen is finding biological solutions to benefit agriculture and forestry

There are more than 50,000 species of mites and ticks known to science. But, because they are tiny and their complex morphology is difficult to categorise, they are among the world’s least studied invertebrates.

When we consider that new research led by the American Museum of Natural History suggests there are 18,000 species of birds on the planet, 50,000 species of mites and ticks seems a substantial number, a huge biodiversity hidden in plain sight. Yet acarologists, who study mites and ticks, insist that this number is relatively small.

“According to some reports, the number of species of mites could reach up to a million,” says Alexander Khaustov, a senior researcher in the acarology research group at Russia’s University of Tyumen. “Each year a huge number of new species of mites are discovered, and our laboratory is one of the world leaders in this field. Over the past six years, we have found about 600 new species,” he says.

The group’s research is divided between the fundamental study of acarology – the taxonomy, fauna, evolution and ecology of mites and ticks – and adopting an applied approach that could benefit industries such as agriculture and forestry. This feeds into the Institute of Environmental and Agricultural Biology (X-BIO) at Tyumen’s broader strategy of looking for scientific breakthroughs to support agriculture and biosecurity, and its efforts to protect humans, animals and plants from biological threats.

Mites and ticks may be small in stature, but they are massively important to industries such as agriculture, where pest control is a perennially evolving problem. With a short life cycle, high fertility and the ability for successive generations to develop a genetic resistance to pesticides, mites are a major concern.

“Some mites pose a serious threat to various agricultural sectors,” explains Dr Khaustov. “For example, spider mites are able to multiply very quickly and completely destroy agricultural plants and crops in a short time. This is especially true for greenhouses. Some species of mites can transfer spores of pathogenic fungi and are indirect pests. Significant damage is caused by mites that harm food supplies, especially grain and its processed products.”

While mites are part of the problem, they can also be part of an ecologically sound solution. Tyumen’s acarology research group is collaborating with industry partners in the search for predatory mites that could be used for plant protection. Introducing a predator to depopulate a crop of potentially damaging mites offers an organic alternative to a problem that might currently be controlled through pesticides. This is an area in which Omid Joharchi, an X-BIO Institute researcher and associate professor at Tyumen, has considerable experience.

Dr Joharchi has a PhD in agricultural entomology from the Islamic Azad University in Iran, where his research involved the study of Gaeolaelaps aculeifer, a soil-dwelling predator mite that could potentially be deployed to control nematodes, thrips and acarid mites among bulb crops. Dr Joharchi says that finding biological solutions to pest control might not only be more effective in protecting agricultural yield, but safer than chemical alternatives.

“Pesticides sprayed on fruits and vegetables accumulate on the outer peel or skin, but the skin does not form an impermeable barrier,” Dr Joharchi explains. “Some pesticides are actually designed to be absorbed into the tissue of the fruit or vegetable to protect it from pests that penetrate the skin to suck out the liquid inside. Imagine that just one drop of pesticide has accumulated in an apple… how many apples do you eat in your whole life? That’s just one example. Long-term pesticide accumulation in human bodies has been linked to the causation of diseases.”

Finding predatory mites and developing practical biological solutions to pest control leads back to the fundamentals of acarology, and the discovery and classification of new species of mites and ticks. In conducting this work, Tyumen’s research group collaborates with acarologists across the globe. “Research in acarology is virtually impossible without international cooperation,” says Dr Khaustov. “A constant exchange of information and materials is required.”

One ongoing collaboration is Tyumen’s new Forest Biosecurity Center, a joint research laboratory that enables the group to work with their US counterparts at Northern Arizona University to learn more about a pest that is a clear and present danger to US forests, the bark beetle. There are thousands of species of them. Some are healthy to forestry, taking root in rotting bark and dying trees, accelerating the composting of organic matter. Others, such as the mountain pine beetle, kill healthy trees in their millions.

“Researchers at the University of Tyumen have extensive experience in studying mites associated with bark beetles,” says Dr Khaustov. “And researchers at the Northern Arizona University have extensive experience in the study of the biological and environmental characteristics of bark beetles. This cooperation is complementary and mutually beneficial.”

Dr Khaustov believes that Tyumen’s excellent technological and academic infrastructure equips it to support more collaborations and continue to seek biological solutions to pests such as termites and bark beetles. “One of the most important practical tasks will be searching for predatory mites in Western Siberia to identify species that can control these pests,” he notes.

In this regard, acarologists have observed the phenomenon of parallel evolution in parasitic mites. “Highly specialised forms of parasites or symbionts appear in relation to a particular species or group of host species,” Dr Khaustov explains. This phenomenon may help to identify mites that could control pests such as bark beetles.

The research group will also continue to study the fundamentals of mites. As the numbers suggest, there is much work yet to be done.

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