Mosquitoes can carry viruses that threaten human health, making surveillance and prevention a continuing public health priority. Image: U.S. Centers for Disease Control and Prevention.

A new approach to capture waste from mosquitoes could strengthen early warning systems for emerging health threats

When public health researchers want to know whether diseases such as COVID-19 or polio are circulating in a community, they can look for genetic evidence in wastewater.

Entomologist Dana Price holds a tube containing mosquito waste collected for genetic analysis. Courtesy of Dana Price.

Entomologist Dana Price wondered whether the same principle could be applied to mosquitoes. The question led to an unconventional experiment.

“What we did, colloquially, was build a mosquito toilet,” said Price, an associate professor at the Center for Vector Biology, Department of Entomology in the School of Environmental and Biological Sciences and a lead author of a study published in Microbiology Spectrum.

The device, Price said, is deceptively simple: a 3D-printed funnel coated with a superhydrophobic (water-repelling) material that causes liquid to bead up and slide into a collection tube. 

The tiny traces of mosquito waste it captured revealed a hidden world.

By sequencing genetic material in mosquito excrement, Price recovered a complete West Nile virus genome, found the first known evidence of a Hedwig-like virus in the Americas and detected several viruses that may be new to science. The approach also identified parasites and confirmed the mosquito species that deposited the waste droplets.

Findings from the study suggest mosquito waste could become a powerful surveillance tool, allowing scientists to search broadly for familiar pathogens as well as threats they don’t yet know exist, Price said.

“If you don’t look for it, you won’t find it,” Price said. “But what if you don’t know what to look for?”

Mosquito surveillance historically involves collecting large numbers of insects, sorting them by species, combining them into pools and grinding them up for laboratory testing.

The labor-intensive process requires scientists to preserve the insects carefully, so their genetic material doesn’t degrade. During an outbreak, those steps can delay information needed to direct mosquito-control efforts. Conventional tests also target specific pathogens, so researchers must know what they are looking for.

Mosquitoes excrete small amounts of liquid containing genetic traces of viruses and other organisms. Because the waste contains far less mosquito tissue, and therefore less mosquito DNA, than a crushed insect, the scientists reasoned that viral material might be easier to find.

Dana Price of the Center for Vector Biology sets a mosquito-waste collection trap in the field as researchers work to adapt the approach for real-world surveillance. Courtesy of Dana Price.

The researchers collected two groups of 50 wild Culex mosquitoes from a yard in New Brunswick, N.J., in 2021 and 2022. They placed each group in a screened container over the funnel and fed them a sugar solution. The mosquitoes produced drops of waste, which slid into a tube.

The scientists used shotgun metagenomic sequencing – used to sequence all genetic material present in a mixed sample. Computers then assembled the millions of fragments generated and compared them with known sequences in scientific databases.

The 2022 sample contained a complete, high-quality genome of West Nile virus, which can cause serious neurological illness in people.

The researchers identified the virus as belonging to the NY07 genetic variant previously found in the region. Such detail eventually could help scientists track how genetic variants of a virus emerge, spread and change.

“What came out was an entire viral genome,” Price said. “Rather than just positive or negative, we have genetic data.”

The researchers were even more intrigued by evidence of a Hedwig-like virus, which hadn’t previously been reported in the Americas.

Hedwig virus was first identified in Europe in snowy owl tissue, prompting scientists to name it after Harry Potter’s famous white owl. Some of the infected birds also had West Nile virus.

Scientists don’t know whether Hedwig-like viruses make birds sick, facilitate West Nile infections or simply coexist with other viruses. The Rutgers finding doesn’t establish that the virus is a threat, Price said. It shows that it has been circulating where no one knew to search for it.

“We didn’t even look for it specifically,” Price said. “We just looked for everything, and we found Hedwig in there.”

He currently is working with officials at the New Jersey Department of Environmental Protection’s Division of Fish and Wildlife to screen organ and tissue samples for the virus. The samples are collected from deceased birds during a post-mortem examination.

A virus found for the first time in a region may have recently arrived or may have gone unnoticed for years. Because few broad mosquito-virus studies have been conducted in North America, organisms that seem geographically restricted may prove widespread.

“The more data we generate, the more we start to wonder if everything is everywhere,” Price said. “Although we don’t yet know how much of everything is everywhere, it may be a lot more than we realize.”

The samples also contained sequences so different from known examples that the researchers classified the viruses as potentially new. They included a partiti-like virus, a picorna-like virus and a possible new virus associated with single-celled parasites infecting the mosquitoes. More study is needed to confirm they are previously undescribed species.

Most appear to infect mosquitoes, other insects or microorganisms living inside mosquitoes and are not known to cause human disease. Some insect-specific viruses may even interfere with mosquitoes’ ability to carry West Nile, dengue or Zika viruses.

The waste also contained traces of trypanosomatids, a group of single-celled parasites known to infect mosquitoes. Mosquito DNA confirmed that the insects belonged primarily to the Culex pipiens group, a West Nile carrier.

Price said the research was an initial demonstration, not a replacement for existing surveillance. It examined 100 mosquitoes from one location, which were transferred to the funnel in a laboratory.

Researchers also cannot conclude from waste alone that a mosquito can transmit a virus, Price said. It could be infecting the mosquito or another organism inside it or simply passing through.

For now, the technique can answer a broader question: Is a pathogen circulating in this environment?

The team is working toward a field-ready trap that would collect mosquitoes and their waste. Price eventually envisions a system that could prepare samples, sequence genetic material, analyze the results remotely and alert scientists to a possible threat in real-time.

“The pie-in-the-sky idea is a device that we place in a forest somewhere, and it’s constantly just beaming back data to us,” Price said.

Such a system could be especially valuable in remote or resource-limited areas, he said. It could reveal known pathogens before they cause widespread illness and expose the ones no one yet knows to look for.

Other Rutgers researchers on the study include: Mehdi Javanmard from the Department of Electrical and Computer Engineering in the Rutgers School of Engineering; Taewon Han, an assistant research professor from the Department of Environmental Sciences in the School of Environmental and Biological Sciences; 

Nicole Wagner, a laboratory researcher; and former undergraduate students Miranda Barnes and Fiona Bezhani.

This article first appeared on Rutgers Today.

 

Scientists are solving the mystery of how rats and mice are growing resistant to conventional pest control methods.

For years, pest control professionals throughout the Northeast have reported a troubling pattern. In some neighborhoods, rodents seemed increasingly more difficult to eliminate, even when standard control methods were used.

Now researchers at Rutgers University believe they may know one reason why.

A study found that 84% of house mice sampled from urban areas in the Northeast carried at least one genetic mutation linked to rodenticide resistance, suggesting many mouse populations may be evolving ways to survive the poisons commonly used to control them. The research was published in the international journal Pest Management Science.

“Pest management professionals often told us that rodent control was becoming more difficult in some areas, even though they applied the effective rodenticides,” said Jin-Jia Yu, a postdoctoral fellow in the Department of Entomology at the Rutgers School of Environmental and Biological Sciences and the first author of the study. “I wanted to find out whether this was occurring in the northeastern United States, especially the metropolitan areas, and how widespread the problem might be.”

Yu works in the laboratory of Changlu Wang, an extension specialist in the Department of Entomology and one of the nation’s leading experts on the management of urban pests, including cockroaches, bed bugs and rodents.

Rutgers researchers Changlu Wang, right, and Jin-Jia Yu found that many urban rats and house mice in the Northeast carry genetic mutations associated with resistance to commonly used rodenticides. Credit: Wang Lab

The researchers analyzed DNA from 147 house mice and 143 Norway rats collected from urban areas in New York, New Jersey, Pennsylvania and Washington, D.C. They focused on a gene called Vkorc1, where certain mutations have been associated with resistance to anticoagulant rodenticides, the most widely used rodent-control chemicals in the U.S.

The results were striking.

Among the house mice examined, 84% carried at least one mutation in the Vkorc1 gene, and nearly 70% carried mutations already known to help mice survive common rodenticides. About 35% of the Norway rats also carried mutations in the same gene.

“We found that resistance appears to be much more widespread in house mice than many people realized,” Yu said. “Norway rats also carried genetic mutations, but scientists do not yet know whether most of those mutations affect Norway rats’ susceptibility to rodenticides.”

The team also identified several genetic variants that had never before been reported in house mice or Norway rats. Scientists don’t yet know whether those newly discovered mutations contribute to rodenticide resistance.

The study emerged from several years of conversations between Rutgers researchers and pest-management professionals, many of whom reported persistent rodent problems despite repeated treatments.

The findings point to a long-running evolutionary contest between humans and one of their oldest urban adversaries. Anticoagulant rodenticides have been used for decades to suppress rat and mouse populations. Over time, rodents carrying mutations that help them survive exposure to those chemicals may gain an advantage, allowing resistance traits to spread through populations.

Researchers found that house mice appear to be adapting more rapidly than rats. One possible explanation involves behavior. Mice are naturally curious and more likely to investigate and consume unfamiliar food sources, including poison baits, Yu said. Rats, by contrast, tend to be cautious and suspicious of new objects.

“Rats are very clever,” Yu said. “They will approach the novel food many times before they really take the food or the bait.”

The findings have important implications for public health. Rodents, which contaminate food, damage buildings and infrastructure, can spread diseases and parasites. If commonly used rodenticides become less effective, communities may face greater challenges controlling infestations.

“This research provides some of the first information on rodenticide resistance in the northeastern United States,” Yu said. “By understanding how prevalent the mutations are and where resistance exists, pest management professionals and public health agencies can make better decisions about how to control rodents.”

Wang, a coauthor of the study, said the findings underscore the need for a broader approach to rodent management.

“Rodents are more than a nuisance,” Wang said. “As resistance becomes more common, it becomes even more important to use science-based management strategies that protect both public health and the environment.”

The scientists’ goal is to help communities manage rodent populations effectively while reducing environmental risks. “Studies like this help us understand how rodent populations are changing and how our management strategies need to evolve with them,” he added.

Rather than relying exclusively on chemical controls, researchers recommend combining multiple strategies, including sealing entry points, improving sanitation, modifying habitat and using traps when appropriate.

“Ultimately, we want to help communities maintain effective rodent control, reduce unnecessary pesticide use and protect public health,” Yu said.

Other Rutgers researchers who contributed to the study included: Alvaro Toledo, an assistant professor; Xiaodan Pang, a postdoctoral associate, and Babatunji Daramola, a graduate student, all in the Department of Entomology in the School of Environmental and Biological Sciences.

This article first appeared in Rutgers Today.

 

Grayson Tung, Senior Coordinator for the Pesticide Safety Education Program, RCE.

We are pleased to announce that Grayson Tung has joined Rutgers Cooperative Extension as the new Senior Coordinator for the Pesticide Safety Education Program (PSEP).

As Senior Coordinator of PSEP, he will help lead statewide educational and certification programs for pesticide applicators across New Jersey. The Rutgers Pesticide Safety Education Program provides training and educational resources to farmers, landscapers, pest management professionals, mosquito control personnel, and other stakeholders to support safe, effective, and legally compliant pesticide use throughout the state. 

Tung brings strong expertise in insect biology, applied entomology, education, and public engagement. We are excited to welcome him to Rutgers and look forward to the many contributions he will make to Rutgers Cooperative Extension and New Jersey integrated pest and mosquito management.

Please join us in welcoming Grayson Tung to Rutgers University!

 

George Hamilton, professor and extension specialist, retired from Rutgers on January 1, 2026.

Effective January 1, George Hamilton GSNB’85, extension specialist in pest management and professor in the Department of Entomology, retired from Rutgers University, concluding a distinguished 38-year career marked by excellence in extension, research, teaching and service to the university and the agricultural community.

A member of the faculty since 1987, Hamilton made significant contributions to the fields of entomology, pesticide safety education, and the management of invasive insects affecting agriculture in New Jersey. He served as chair of the Department of Entomology for 15 years and held numerous university and statewide advisory roles related to pesticide regulation, environmental protection and agricultural policy.

Trained as an environmental biologist and entomologist, Hamilton earned his doctoral degree in entomology from Rutgers in 1985. Over the course of his career, he authored more than 200 research and extension publications addressing integrated pest management, pesticide use and environmental protection.

Through his work with Rutgers Cooperative Extension, Hamilton became widely recognized for advancing pesticide safety education and integrated pest management programs that support New Jersey’s agricultural industries while protecting environmental and public health. His extension efforts reached thousands of growers, professionals and residents each year through workshops, training programs and outreach presentations.

Among his many contributions, Hamilton played a key role in statewide and national efforts to manage the invasive brown marmorated stink bug, a pest that threatens fruit, vegetable and specialty crops. His research helped improve monitoring and management strategies and contributed to multi-state integrated pest management initiatives aimed at reducing the pest’s impact on agriculture.

He also led and supported the development of integrated pest management programs for a range of crops in New Jersey, including tree fruit, vegetables, blueberries and field crops. These programs helped growers reduce pesticide use while maintaining crop productivity and environmental stewardship.

Nationally, Hamilton was an active leader in the Entomological Society of America, serving as treasurer and president of the Eastern Branch and completing two terms on the ESA Board of Governors.

During his career, Hamilton received numerous state, national and international honors, including awards from the ESA and the U.S. Department of Agriculture recognizing his contributions to research, extension and integrated pest management programs.

 

Adult female Asian longhorned ticks attached to vegetation and waiting for a host to come by. Photo: Jim Occi.

A pair of new studies led by researchers at the Rutgers Center for Vector Biology use genetic data to help trace the potential routes of introduction of the invasive (ALT), Haemaphysalis longicornis, into the United States, and to identify potential vaccine targets within the tick that can be exploited to protect vulnerable livestock populations.

While this tick is native to China, Japan and the Republic of Korea, one lineage in particular is rapidly spreading through multiple countries, including Australia, New Zealand and various Pacific Islands. This lineage has the rare ability to reproduce without the presence of male ticks, a phenomenon known as parthenogenesis.

In 2017, the presence of parthenogenetic Asian longhorned ticks in the U.S. was first reported in New Jersey, said Dana Price, assistant professor in the Department of Entomology. However, historical samples have now shown evidence of the ticks’ establishment as early as 2010 in West Virginia. As vectors of Theileria orientalis—a parasitic livestock pathogen—H. longicornis poses a substantial threat to U.S. livestock. 

Assistant professor Dana Price in the lab.

In the first study, published in Ecology and Evolution, researchers led by Price and doctoral student Zoe Narvaez, utilized genome sequence data from the tick’s mitochondrion (or mitogenomics) to determine the source and frequency of ALT introductions to the U.S. By comparing DNA from hundreds of Asian longhorned tick samples from different regions in the U.S. to those of native and invasive samples from East Asia and Oceania, the authors were able to determine that there were very likely at least four separate introduction events to the United States from particular regions in Japan and the Republic of Korea.

Global economic losses due to tick-borne diseases are estimated at $22-30 billion annually. To mitigate such huge losses, chemical acaricides are routinely used to control ticks, including ALT, on and around livestock, companion animals, and humans.  Reliance on chemical treatments alone can result in the development of resistance in tick populations. Vaccines administered to animal hosts (cows, for example) that prime the host immune system to generate “anti-tick antibodies” that are in turn delivered to the tick as it feeds on host blood represent novel and emerging tools for tick control in conjunction with acaricide treatments.

In their paper published in BMC Genomics, Price and postdoctoral research associate Mohamed Moustafa, in conjunction with collaborators at USDA-ARS and Texas A&M AgriLife Extension Service, sequenced the complete genome of North American H. longicornis ticks and screened more than 21,000 of its genes to identify those that the cattle immune system would recognize as “foreign” (or antigenic) to induce antibody production.

The Price lab has currently moved four such genes to the next step in the process, which involves assessment of reproductive capacity and/or morbidity in the tick when each gene is silenced using RNA interference.

“These studies are a critical step toward protecting livestock producers in the United States,” said Price. “By tracing the origins of this invasive species and identifying genetic weak points to exploit with emerging technologies, we’re developing tools that could ultimately transform how we manage ticks and the diseases they carry.”

References:
Narvaez, Z.E., Egizi, A.M., Yabsley, M.J., Thompson, A.T., Moustafa, M.A.^**, Alt, E., Bickerton, M., Bjorgo, K., Butler, R.A., Cumbie, A., Eastwood, G., Falco, R.C., Fonseca, D.M., Hang, J., Harper, V.L., Lewis, N., Lovy, J., Maestas, L.P., Mather, T.N., Nakao, R., Occi, J.L., Rainey, T., Sal, M., Stoops, C.A., Trout-Fryxell, R.T., Watson, W., Wagner, N.E., Zheng, A., Saelao, P., & Price, D.C. (2025). Multiple introductions of the Asian Longhorned Tick (Haemaphysalis longicornis) to the United States revealed using mitogenomics. Ecology and Evolution, 15(4): e71312, 14pp. https://doi.org/10.1002/ece3.71312 

Moustafa M.A., Barnes M.M., Wagner N.E., Bodine D., Bendele K., Teel P.D., Saelao P., Price D.C. (2025). Genome of the invasive North American Haemaphysalis longicornis tick as a template for bovine anti-tick vaccine discovery. BMC genomics, 26(1):307.

 

Cesar Rodriguez-Saona.

The Award for Excellence in Integrated Pest Management recognizes outstanding contributions to IPM, with special consideration for independence of thought and originality. Rodriguez-Saona’s research on IPM in blueberry and cranberry crops has provided growers with practical, science-based tools to manage insect pests while reducing reliance on broad-spectrum insecticides. His work has significantly advanced the use of behavior-based strategies, biological control, and reduced-risk insecticides.

Through his extension program, Rodriguez-Saona has reached hundreds of growers across New Jersey and beyond, promoting sustainable pest management practices that enhance both the economic and environmental sustainability of berry production systems. He has delivered more than 300 presentations to growers, crop consultants, extension agents, and researchers nationally and internationally. His outreach efforts include field days, grower meetings, newsletter articles and educational videos focused on pest identification and management.

“I am honored to receive the Award for Excellence in Integrated Pest Management from the Eastern Branch of the Entomological Society of America. I am deeply grateful to my colleagues, growers, research collaborators, and funding agencies for their invaluable support of my work in insect pest management research and extension,” said Rodriguez-Saona.

Changlu Wang at work implementing integrated pest management in multi-family housing.

The Distinguished Achievement Award in Extension recognizes outstanding contributions in the area of extension and demonstrated excellent performance through program creativity, impact, achievement and delivery. Wang’s research on IPM in apartment buildings have provided practical solutions on how to implement IPM in multi-family housing and the benefit of IPM for reducing indoor health risk including pests, pest allergens, and insecticide residues. His extension program has reached thousands of low-income homes throughout New Jersey and other states, with the goal of reducing pest problems and environmental risks in the urban environment, improve quality of life and protect public health. Wang has also presented numerous talks to pest management professionals, housing staff, public health workers in the U.S. and internationally.

“I feel honored to receive this prestigious award from the Eastern Branch of ESA. I am thankful to the colleagues, housing authorities, funding agencies for supporting my effort in urban pest management research and extension,” said Wang.

As part of a broad-based urban pest management outreach program, Wang has produced several highly impactful bed bug videos with the most popular video receiving 47 million views.

 

Zoe Narvaez presenting statewide tick-borne pathogen surveillance results at the 2024 meeting of the New Jersey Mosquito Control Association, Atlantic City, NJ.

Zoe Narvaez, a PhD candidate in Entomology and a National Science Foundation Graduate Research Fellow, was awarded a travel grant by the Northeastern Mosquito Control Association (NMCA) to present the findings of her dissertation at their 2024 annual meeting in Plymouth, Massachusetts this month. In late 2023, the NMCA awarded Narvaez the Jobbins Scholarship, which honors outstanding research in vector biology.

For her doctoral dissertation, Narvaez has been researching the ecology of tick-borne diseases in the “fragmented” forests of New Jersey. Her findings reveal another layer to the folly of urban sprawl – that the rich patchwork of undisturbed forests and preserves, cherished as respites from the downsides of urban and suburban life, may be incubators for tick-borne pathogens like those causing Lyme disease and Powassan virus.

“NJ has the highest density of preserved parkland in the contiguous U.S. We have so many small, isolated urban forests – tick habitats adjacent to where we live and work,” said Narvaez. “There’s a growing body of evidence that when you fragment forests and habitats, there can be changes in the abundance of ticks and tick-borne pathogens. Some worry that human development may be driving more intense tick-borne disease.”

An undergraduate entomology researcher collects host-seeking ticks from dense foliage through the “flagging” method at Cheesequake State Park, July 2023.

Narvaez also presented this work at the November 2024 meeting of the Entomological Society of America in Phoenix, AZ where she won first place in the “Ecology, Vector Biology, and Management” graduate competition section for the second year in a row.

“I’ve always been interested in diseases transmitted by bugs,” said Narvaez, whose work in vector biology started when she was in high school working in mosquito control, helping to kill larvae. “The diseases are really complex and have to be very clever and insidious to evade the immune systems of both the bug and the animal.”

Fortuitously, her employer from high school introduced her to her PhD advisor at Rutgers. Narvaez studied public health at the University of Oklahoma as an undergraduate and plans to complete her PhD in the spring of 2025.

 

Honeybee pollinating blueberries. Photo courtesy of Cesar Rodriguez-Saona.

Cesar Rodriguez-Saona, extension specialist in entomology, Department of Entomology, is the principal investigator of a two-year, $199,783 grant from the USDA Crop Protection and Pest Management program for the project, “Improving Management of a Key Insect Pest of Blueberries Through Optimization of Pollination Services,” from September 1, 2024, to August 31, 2026.

Plum curculio adult on blueberry fruit. Photo courtesy of Cesar Rodriguez-Saona.

This grant is part of a $20 million investment by the Crop Protection and Pest Management (CPPM) program to address high priority issues related to pests, including insects, nematodes, pathogens, and weeds, and their management using IPM approaches at the state, regional and national levels. The program supports projects that will increase food security and respond effectively to other major societal challenges with comprehensive IPM approaches that are economically viable, ecologically prudent, and safe for human health.

Rodriguez-Saona and Rutgers post-doc Beth Ferguson, who is co-principal investigator on the grant-funded project, are investigating an integrated pest and pollinator management strategy for plum curculio, a persistent pest of blueberries in the mid-Atlantic. This pest damages the blueberry fruit through a scar left by feeding damage and from laying eggs, resulting in premature fruit drop from larvae.

Rutgers post-doc Beth Ferguson, in the field.

Management can be conducted post-bloom, but pesticides cannot be applied while honeybees are present, explained Rodriguez-Saona.

“Because plum curculio adults arrive in blueberries around peak bloom, growers cannot adequately respond to increasing populations. Honeybee hives are currently kept in blueberries until the end of bloom, but whether this contributes significantly to yields is not known. The benefits of removing hives early to increase yields and better manage plum curculio may outweigh any effects on late-season fruit production.”

The overall goal of the funded project is to use plum curculio management as a model for effective creation and implementation of integrated pest and pollinator management strategies in pollinator-dependent crops.

 

In an ever more connected world, scientists say that the appearance of invasive insects, such as the spotted lanternfly, should be expected.
A. Nielsen

In 2003, Anne Nielsen became the first doctoral student in the U.S. to study the brown marmorated stink bug, which was beginning its ascendancy as an invasive species notoriously damaging to crops.

Working with her mentor, Rutgers entomologist George Hamilton, Nielsen traced the stink bug’s life cycle and origins. By the time the stink bug populations exploded in 2009-2010, Nielsen and Hamilton were in a unique position to advise farmers on countermeasures.

Now an associate professor in the Department of Entomology in the Rutgers School of Environmental and Biological Sciences (SEBS), Nielsen is also an Extension Specialist in tree fruit, with a special focus on invasive species like stink bugs and spotted lanternflies and their effects on fruit crops. Her goal is to protect the natural world by developing sustainable management practices.

After a morning spent with students in a peach orchard at the Rutgers Agriculture Research and Extension Center in Bridgeton, N.J., Nielsen discussed the threat of invasive species and the continuing effort to contain them.

Rutgers entomologist Anne Nielsen (second from right) employs a peach orchard at the Rutgers Agriculture Research Extension Center in Bridgeton as a natural laboratory. (From left) Tara Esposito, a Moorestown Friends School student, SEBS sophomore Abigail McFarland, Nielsen and Ann Rucker, a tree fruit entomology technician, collect invasive insects for study. Anne Nielsen.

What are invasive species?

An invasive species is a non-native species that is causing economic or ecological harm. They are more than just minor annoyances. They can cause major economic damage each year.

Invasive species are not going away. They are part of our lives because the world is so connected now. It’s something we need to continue to confront because it’s going to keep happening.

You just spent hours in a peach orchard with your students. What were you studying?

I’m out there looking at the whole system, the ecological environment. We look at the fruit trees, the grass underneath and the woods surrounding the orchard, and think about the natural enemies present. We take the whole picture into account and fit puzzle pieces together.

We study the biology of invasive insects so that we can figure out when they’re present and identify the correct timings for management. We also look at their behavior. We’ve done a lot of work looking at how they move across the surrounding landscape and within an orchard, and then we can exploit that behavior for management. We’ve found what we call border spray techniques, so we can reduce the amount of area in the orchard that is sprayed with pesticides. This is part of the strategy we are developing to incorporate biological techniques that are more environmentally friendly.

You are engaged in an ongoing battle against invasive species. What are the stakes?

New Jersey is the Garden State; agriculture is at the heart of who we are. These invasive species come in and they change our production practices, how we view agriculture and insects. Insects get vilified. We must balance our management of invasive insects with consumer demands for clean fruit and less pesticides.

Peach crops, and fruit crops in general, can be destroyed by invasive species. New Jersey is the number four growing region for peaches in the country. At the height of the marmorated stink bug infestation from 2010 to 2011, we lost 60 percent of our peach crops.

We also have a lot of apple orchards and wine vineyards that are vulnerable to these pests, as well as farms with equally imperiled small fruits like blueberries and raspberries. These crops are tied to a lot of people’s livelihoods and provide great economic value to the state.

When we think of economic loss from invasive insects, we see there are multiple factors driving that phenomenon, including some that incur hidden costs. There’s an invasive fruit fly called spotted wing drosophila that is a major pest of small fruit like blueberries and raspberries. I know growers who have pulled up all their raspberry plants. One wine grape grower handpicks stink bugs out of the grapes on the processing line before crushing the grapes to maintain high quality wines.

How do invasive species get here?

There are a lot of different routes of introduction for an invasive species. The most common one that we see is associated with shipping containers and global trade. We have a lot of ports of entry in this region. New Jersey and most of the mid-Atlantic are so densely populated that farms are often near urban areas, forming what we call the agro-urban interface, increasing the odds of invasive species reaching crop areas.

When you refer to achieving a balance in nature, what do you mean?

Invasive insect species, such as the brown marmorated stink bug, are believed to have arrived in the U.S. through international shipping containers. Anne Nielsen

We had been looking at marmorated stink bugs for some time before they reached outbreak levels. We had a couple of bad years and then the populations naturally declined. A lot of invasive species exhibit these boom-and-bust cycles in their populations. Several factors come together – the environment starts pushing back, scientists develop new methods – and we’re able to reduce the population.

What sort of natural controls are evolving for the brown marmorated stink bug?

A lot of our focus now is on biological control of the stink bug using a parasitoid species – a tiny stingless wasp about the size of a poppy seed. They lay their eggs inside stink bug eggs. When those eggs hatch, they destroy the stink bug eggs. This has the potential to help control populations over time in a more sustainable manner.

We have done a few small releases of the wasps with farmers in New Jersey and at the Rutgers research station. We’re still working out the method’s biological impact.

How did you get involved in spotted lanternfly research?

The lanternfly was first detected in New Jersey in 2018 and in Pennsylvania a few years before that. Most of the explosive growth of the lanternfly coincided with the pandemic.

We studied it in Pennsylvania early on, learning how to identify it, and understand what trees it liked. In 2019, we started receiving significant reports from farmers in New Jersey about infestations in wine grapes.

In collaboration with Julie Lockwood, [a professor in the Department of Ecology, Evolution and Natural Resources at SEBS], we devised a method identifying lanternflies through genetic signatures. We were able to combine this detection method to inform our growers during the pandemic and reducing pesticide use by figuring out the best materials to use and the best times to spray. And we’re still battling them.

We are actively looking for biological control approaches to limit the lanternfly population and have found a few candidates. But we are still figuring this out.

This article first appeared in Rutgers Today.

 

Anne Nielsen is an Associate Extension Specialist in Entomology at Rutgers–New Brunswick. Courtesy of Anne Nielsen.

Rutgers groundbreaking women researchers are making history and making a difference in the world every day. From serving as mission head for NASA’s next space telescope to creating nanorobots to target disease and studying the survival of orangutans in Borneo – one of our closest living relatives – they are advancing our understanding of the natural and physical world around us.

For Women’s History Month, Rutgers Today asked some of Rutgers acclaimed scientists to share their own history of what inspired them to enter their field. Among them is Anne Nielsen, Associate Extension Specialist in Entomology at the School of Environmental and Biological Sciences.

Here is her story.

Somewhere in my parent’s house is a childhood video of me explaining the 17-year cicada life cycle to my much less enthused friends. I didn’t know it then, but this was an early insight into what grew into a love of insects (bugs specifically). 

I grew up in a family where a passion for science was a thread that bound us together. We lived outdoors as we gardened, hiked and vacationed in national parks. Through these experiences, I gained an appreciation for the natural sciences and was convinced I would spend my adult life as a National Geographic photographer lying in wait for the perfect lion picture. That dream meandered a bit to something a bit more practical as a physical therapist or orthopedic surgeon but I didn’t lose my love of the outdoors. 

I was first exposed to entomology while studying biology at Virginia Tech where I assisted in honeybee research. These tiny animals quickly fascinated me with their intricate behaviors and connections. However, it took a three-year break after college before the pull of entomology and the outdoors was too great, and I started a doctoral program at Rutgers with George Hamilton studying the life history of an invasive stink bug species. While my route to becoming a ‘Woman in Science’ wasn’t linear, the culmination of my experiences allowed me to appreciate the opportunities that led me here. Now as an extension specialist and associate professor in Entomology at Rutgers, I can integrate my passion for protecting our natural world through studying sustainable management practices to protect tree fruit from insects.  

Anne Nielsen’s story first appeared in a Women’s History Month feature in Rutgers Today.