EPN – Dillman Lab

New Publication: The Oral Toxicity of Steinernema carpocapsae Venom Proteins

We are excited to share our newest publication in Toxins, led by Manisha Mishra, which explores a previously unknown aspect of entomopathogenic nematode biology: the oral toxicity of their venom. While Steinernema carpocapsae nematodes are well-known biological control agents, our team demonstrated for the first time that their secreted venom proteins are highly toxic when simply ingested by the destructive crop pest Spodoptera frugiperda (fall armyworm). Feeding these venom proteins to early-instar larvae caused significant developmental delays and mortality, with surviving larvae facing severe carry-over effects such as malformed pupae and a drastically reduced adult emergence rate of only 19% at the highest doses. Furthermore, surviving adult moths lived 30% shorter lives and laid over 90% fewer normal eggs, disruptions that coincided with a massive spike in the insects’ oxidative stress and detoxification enzyme activity. Ultimately, these exciting findings position nematode venom as a promising new resource for discovering eco-friendly insecticidal proteins to improve sustainable pest management strategies.

New Entomopathogenic Nematode, Steinernema adamsi, Described

S. adamsi emerging from host We have characterized a new species of entomopathogenic nematode (EPN). This EPN was isolated from Thailand and falls within the Longicaudatum clade, being closely related to Steinernema hermaphroditum. The nematode was named after Dr. Byron Adams, who was Dr. Dillman’s undergraduate mentor and who introduced Dr. Dillman to EPNs in 2003. Steinernema adamsi is the newest EPN to be described and has much to teach us about how nematodes parasitize insects. It may also be useful in biological control. A UCR press release has additional information.

Proof of Concept Funding

We are excited to learn that our work on nematode-derived toxins will be supported by proof of concept funding by UCR. “We look for projects that promise to solve one or more urgent problems. We help those researchers with a little seed funding to move their work closer to commercialization,” explained Mark Leibowitz, interim director of UCR’s Entrepreneurial Proof of Concept and Innovation Center, or EPIC.”

“Adler Dillman, an assistant professor of nematology, received $30,000 to identify the proteins some nematodes secrete when they infect an insect and kill it. Dillman plans to use the toxin in a pesticide, or genetically modify crops to produce the protein and become naturally insect-resistant. Most corn and cotton in the U.S., for example, has been genetically modified to produce a protein called BT toxin, originally found in a type of bacteria. But insects are starting to resist BT toxin, and the nematode-derived toxin could serve as a supplement or alternative.”

https://news.ucr.edu/articles/2019/01/10/awards-help-faculty-commercialize-inventions

Sand cricket resistance to EPN infection

Congratulations to Sudarshan, Dihong, Kathleen, Lauren, and Carter on the recent publication of their work on sand crickets. We are excited that this paper includes 3 undergraduate students as co-authors. We are eager to continue our research on S. scapterisci and its relationship with its bacterial symbiont X. innexi. This specialist parasite is becoming more interesting the more we learn about it.

New paper published by undergraduate researchers

Congratulations to Valentina and Shyon on the publication of their work on EPN activation. This research effort was led by Valentina and is the culmination of research that she’s been doing in the lab since January 2017. Shyon joined the project in January of this year and was able to make a significant contribution to this project. We support helping undergraduates publish their research.