South Middlesex Times

Rutgers University-New Brunswick scientists have discovered a virus responsible for a nationwide die-off of superworms, commonly used as food for birds, reptiles, other pets, and increasingly humans as an alternative protein source. This discovery also introduces a novel method for identifying emerging viruses and pathogens in humans, plants, and animals.

Using beetle carcasses processed into a slurry and examined with an electron microscope cooled by liquid nitrogen, the researchers identified what they have named Zophobas morio black wasting virus. The name reflects the virus's lethal impact on Zophobas morio beetles, particularly during their larval stage when they are known as superworms due to their size.

The larvae of Z. morio are a staple diet for various captive exotic animals worldwide. However, in 2019, these larvae began dying off mysteriously, causing concern among pet food suppliers and owners.

Jason Kaelber, an associate research professor at the Institute for Quantitative Biomedicine (IQB) at Rutgers-New Brunswick, collaborated with Judit Penzes, the study's first author and postdoctoral associate at IQB. "Judit was looking to identify the reason beetle farmers were losing all their superworm colonies to a deadly disease and I was looking to develop ways of discovering new viruses that don’t depend on DNA or RNA sequencing," Kaelber said. "We ended up discovering the virus that has been sweeping the country and killing superworms."

The investigation began over a year ago when Penzes was contacted by beetle farm owners experiencing high mortality rates among their superworms. Known for her previous work isolating a virus affecting crickets, Penzes collected infected superworms from pet stores in New Jersey.

She then created a slurry from the worm carcasses using a blender and processed it through virus purification methods. A fluorescent light revealed the presence of the virus when it glowed blue. "I said, ‘I got you,’ when I saw it," Penzes recounted.

Penzes worked with Kaelber to examine the virus using cryo-electron microscopy, which provides detailed three-dimensional views of viruses without analyzing DNA. They compared the structure of this new virus with known proteins in Rutgers' Protein Data Bank database and found similarities to a cockroach-affecting virus but identified it as part of the parvovirus family.

“It’s a new one, different from anything that’s been sequenced or imaged before,” Penzes stated.

The study benefited significantly from samples sent by superworm farmers across the nation once they learned about the research. “The eagerness of the farmers to help us out researching the virus had an enormous role in helping this published study to be born,” Penzes said.

Kaelber emphasized that this effort demonstrates how cryo-electron microscopy can be used to discover and characterize new pathogens directly. “In the future, if there’s ever a really important outbreak we're going to want to throw every tool we can at it to see what we can find,” he said.

Following their discovery, researchers tested protective measures against Zophobas morio black wasting virus by injecting beetles with a related non-symptomatic virus from another species. They are now developing a vaccine based on these findings.

“The discovery is important for two reasons,” Kaelber explained. “First, beetle farmers can use this information to protect their colonies and understand which actions will be effective or ineffective at managing the epidemic. Second, the beetle epidemic was a real-world test of technology that we hope can be useful to rapidly investigate future outbreaks in humans, plants or animals.”

Scientists Martin Holm of Rutgers Institute for Quantitative Biomedicine and Samantha Yost of REGENXBIO Inc., Rockville Md., also contributed to this study.