Updated: February 11, 2024 17:31 IST
Los Angeles (US), February 11 (ANI): Researchers have identified a species of microscopic worm that infects and kills insects.
These worms, known as nematodes, have the potential to control crop pests in warm, humid environments where other beneficial nematodes do not currently thrive.
The study was published in the Journal of Parasitology.
This new species belongs to the Steinernema nematode family, which has long been used in agriculture to treat insect parasites without the use of pesticides. Steinernema are harmless to humans and other mammals and were discovered in the 1920s.
“We spray billions of them on crops every year and they’re easy to buy,” said UCR nematology professor Adler Dillman, whose lab made the discovery.
“Although there are more than 100 species of Steinernema, we are always looking for new ones because each one has unique characteristics. Some might be better in certain climates or with certain insects.”
Hoping to gain a deeper understanding of a different Steinernema species, Dillman’s lab requested samples from colleagues in Thailand.
“We did DNA analysis on the samples and realized they were not what we had requested. Genetically, they were unlike anything that had ever been described,” Dillman said.
Dillman and his colleagues have described the new species in the Journal of Parasitology. They are almost invisible to the naked eye, about half the width of a human hair and just under 1 millimeter long.
“Several thousand in a flask looks like powdery water,” Dillman said.
They have named the new species Steinernema adamsi after the American biologist Byron Adams, chairman of the Department of Biology at Brigham Young University.
“Adams has helped refine our understanding of nematode species and their important role in soil ecology and nutrient recycling,” Dillman said.
“He was also my college advisor and the person who introduced me to nematodes. This seemed like a fitting tribute to him.”
Adams, who is currently researching nematodes in Antarctica, said he is honored that such a “cool” species bears his name in scientific literature.
“The biology of this animal is absolutely fascinating,” Adams said.
“Aside from its obvious applications in alleviating human suffering caused by insect pests, it also has much to teach us about the ecological and evolutionary processes involved in the complex negotiations that take place between parasites, pathogens, their hosts, and their environmental microbiome.”
Learning about the life cycles of these worms as a college student is what got Dillman hooked on studying them.
When they are juveniles, nematodes live in the soil with their mouths closed, in a state of arrested development. At this stage, they roam the ground looking for insects to infect. Once they find a victim, they enter through the mouth or anus and defecate highly pathogenic bacteria.
“A parasite that expels pathogenic things to help kill its host, that’s unusual right off the bat,” Dillman said. “It’s like something out of a James Cameron movie.”
Within 48 hours of infection, the insect dies. “It basically liquefies the insect, then you’re left with a bag that used to be its body. You could have 10 or 15 nematodes on a host, and 10 days later you have 80,000 new individuals in the soil looking for new insects to infect,” Dillman said.
Researchers are sure that S. adamsi kills insects. They confirmed this by putting some of them in containers with wax moths. “It killed the moths in two days with a very low dose of worms,” Dillman said.
In the future, researchers hope to discover the nematode’s unique properties. “We still don’t know if it can resist heat, ultraviolet light or dryness. And we still don’t know the variety of insects it is capable of infecting.
However, S. adamsi are members of a genus that can infect hundreds of types of insects. Therefore, researchers are confident that it will be beneficial on some level, whether it turns out to be a specialist or generalist parasite of multiple types of insects.
“This is exciting because the discovery adds another insecticide that could teach us interesting new biology,” Dillman said.
“They also come from a warm, humid climate which could make them a good insect parasite in environments where currently commercially available orchard nematodes have not been able to flourish.” (ME TOO)