Prairie Research Institute

Illinois Natural History Survey

Invasive species pose many risks to native biodiversity, including outcompeting and displacing native species, consuming vulnerable native species, and spreading diseases. Some invasive species can become numerically dominant, disrupting native food webs and altering the physical environment. Invasive species can damage natural areas, degrade ecosystem services, are expensive to control, and once established can be almost impossible to eradicate.

INHS has well established research programs and partnerships working to combat the threat of invasive species. INHS scientists are working to control existing invasions—from the infamous invasive carps to the lesser-known spotted wing drosophila—and prevent future ones.

Aquatic invasive species

Illinois has many aquatic invasive species because of its connection to both the Great Lakes and the Mississippi River, which are common pathways for invasive species introduction.

Invasive carp in Illinois’ rivers

Scientists at the INHS Illinois River Biological Station (IRBS) in Havana, Illinois, are monitoring, controlling, and managing bigheaded carp species (bighead carp and silver carp) in the Upper Mississippi River. Commercial anglers remove the carp species in various strategic locations, and station staff survey the fish through mark and recapture efforts to assess the effectiveness of the harvest. Ultimately, their efforts benefit fisheries biologists and managers concerned with the threat and control of invasive carp species, inform the public and stakeholders about bigheaded carp population dynamics in the Upper Mississippi River, and remove fish to preserve the native ecological integrity of the river.

IRBS researchers also study the underlying factors of a rapid invasion of invasive aquatic species and how these can be exploited to limit the speed and spread of an invasion. This information is key to enhancing and expanding the Illinois Department of Natural Resources-led response and control efforts, as well as continuing to understand bigheaded carps’ effects and constraints.

Scientists at the INHS Kaskaskia Biological Station (KBS) in Sullivan, Illinois, conduct annual monitoring of invasive carp reproduction within the Illinois Waterway to both provide an early warning of any increase or spread of reproductive activity further upriver and to understand how carp removals may impact reproductive productivity of these nuisance species.

KBS and IRBS scientists collaborate on research focused on the effects of bigheaded carp populations on zooplankton communities in the Illinois River and the potential for carp removals to diminish these effects. In addition, INHS researchers at KBS and the Sam Parr Biological Station in Kinmundy, Illinois, use the experimental facilities at these field stations to conduct experiments to assess the risks posed by black carp as predators on native mollusks and the ability of native fish predators to consume bighead carp and silver carp.

Recent research topics related to invasive carps include:

  • Catch rates and cost effectiveness of entrapment gear for bigheaded carps: A comparison of pound nets, hoop nets, and fyke nets in backwater lakes of the Illinois River
  • Evaluation of gear efficiency and bigheaded carp detectability
  • Impacts of invasive bigheaded carp on native food webs
  • Understanding the effects of bigheaded carp on native fishes

Read more about INHS fish and fisheries research.

Invasive clams

Clams in the genus Corbicula are invasive freshwater bivalves that pose a threat to native freshwater mussel fauna in lakes and streams in the United States. In 2008, Corbicula largilllierti appeared in the navigable rivers in Illinois, and an unfamiliar species was discovered in the Illinois River in 2015.

Through collaborations with scientists at the University of Michigan–Museum of Zoology, INHS researchers confirmed this occurrence as a new introduction of a unique Corbicula species. They continue to monitor and track its spread across the United States with the help of colleagues. This research will contribute to our understanding of the effects of Corbicula on native mussels and the extent to which Corbicula may be a factor in mussel declines.

Great Lakes research

The Great Lakes illustrate virtually every problem associated with transfers of species by humans, culminating in an altered ecosystem that no longer maintains itself but requires costly human intervention. For example, quagga mussels have altered energy pathways and significantly reduced overall productivity of the lake, and invasive round gobies and alewife dominate prey fish resources for predators. These changes have led to new questions that Lake Michigan Biological Station (LMBS) scientists strive to answer in studies using a combination of long-term datasets and focused research projects. Annual nearshore fish community monitoring provides the data for a better understanding of invasive species’ habitats, diet, reproduction, and distribution.


Aquatic invasive species specialists with INHS and the Illinois-Indiana Sea Grant provide tools and education that boaters, anglers, water gardeners, aquarium hobbyists, and K-12 educators need to help prevent the introduction and spread of aquatic invasive species affecting Lake Michigan and the inland waters of Illinois and Indiana. They also connect decision makers with the latest information on these detrimental species to inform high-level actions that strengthen and preserve aquatic ecosystems and communities.

Botanical invasive species

Because new botanical invasive species are introduced almost every year, and we are seldom able to completely eradicate them, the total number of plant invasive species in Illinois is increasing. Approximately one-third of the plants in most woodlands, wetlands, and grasslands in Illinois are non-native species. These invasions can cause economic damage, displace native species, alter ecosystem functions, and interfere with ecological restoration goals.

Scientists in the Critical Trends Assessment Program (CTAP) study Illinois wetlands, monitoring their biological condition and tracking changes through time. Since 1997, CTAP has conducted an ongoing, statewide survey of wetlands to document their condition and develop a deeper understanding of how these communities are changing. Researchers are using the CTAP dataset to draw inferences about the nature of these changes, and the conclusions they reach can guide land management decisions. In this way, CTAP is helping to ensure that the rich ecological communities of Illinois wetlands have a promising future.

Researchers in the INHS Wetland Science Program work closely with the Illinois Department of Transportation (IDOT) to protect, maintain, and restore wetlands. These efforts include performing biological surveys and conducting studies of wetland soils, plants, and animals. Previous studies have addressed the causes and consequences of non-native plant invasions in Illinois wetlands and forests. This information informs decisions on IDOT transportation infrastructure initiatives.

Read more about INHS plant research.

Agricultural pests

Agricultural insect pests have always caused problems for Illinois growers. Some pest species have affected crop production for the past century, but newly arrived pests, new pest behaviors, and changes in management tactics demand continued vigilance, research, and action to maintain sustainable and profitable crop production in Illinois. 

The Illinois Cooperative Agricultural Pest Survey Program (CAPS) focuses on the early detection and surveillance of harmful or economically significant exotic plant pests, diseases, and weeds that have eluded first-line of defense inspections or have been identified as threats to U.S. agriculture or the environment. The program’s goal is to safeguard our nation’s food and environmental security from exotic pests and to detect and prevent the spread of invasive species such as the Asian longhorned beetle, spotted lanternfly, sudden oak death, and others. The CAPS program is a joint effort between several state and federal agencies, including INHS, Illinois Department of Agriculture, and the USDA Plant Protection and Quarantine program.

Corn rootworm

Corn rootworm beetles are the most devastating pests of America’s most valuable crop, corn. Annual yield losses and management costs of western corn rootworms (WCR) and the closely-related northern corn rootworm (NCR) may exceed $2 billion across the U.S. Corn Belt. These agricultural pests have evolved resistance to insecticides, annual crop rotation, and every rootworm-specific bacterial toxin engineered into transgenic “Bt” corn hybrids. 

INHS insect behaviorist Joseph Spencer has studied the ecology, behavior, biology, and resistance of WCR for over 25 years, making progress in understanding the role of WCR behavior in pest adaptations to annual crop rotation and Bt corn hybrids. From changes in female egg-laying affinity for cornfields to patterns of intra- and interfield movement in Bt corn and startling adaptations of the WCR microbiota and gene expression in feeding individuals, “paying attention” to what WCR are actually doing is a foundation for understanding. Current work studying the status of WCR and NCR resistance to the toxins expressed in Bt corn hybrids as well as efforts to improve adoption of integrated pest management-based controls are aimed at providing sustainable tactics that work for farmers. Resistance has long been a driver of innovation in rootworm management. Our hope is that studying mechanisms of adaptive rootworm behavior will reveal new vulnerabilities that may make our tactics more durable and effective.

Pest degree calculators

INHS scientist Kelly Estes and Illinois State Water Survey researchers recently updated two pest degree day calculators for commodity and specialty crop growers in Illinois, featuring seven-day weather forecasts, graphs, and insect emergence maps to track accumulated degree days and light for the most notorious pests, including corn flea beetle and the prediction of potential Stewart’s Wilt severity, Japanese beetle emergence, and brown marmorated stinkbug activity. These tools help farmers plan pest management efforts and use pest control more efficiently. Because temperature controls the rate that insects develop, the new degree day calculators use data from the Water Survey’s network of weather monitoring stations so growers can calculate degree days accumulated in their region of the state for specific pests, such as the codling moth, spotted wing drosophila, corn rootworm, or emerald ash borer.

Human pests


Mosquitoes can be vectors for pathogens that infect both people and animals, such as Zika virus and West Nile virus. INHS Medical Entomology Lab scientists conduct statewide monitoring and surveillance of mosquito vectors. Using applied field and lab research, the research team generates ecological, genetic, behavioral and epidemiological data that can guide infection prevention measures in Illinois and more effectively detect, prevent, and control mosquito-borne diseases.

Recent work has focused on detecting the distribution and abundance of the Asian tiger mosquito throughout Illinois; this mosquito can transmit exotic diseases like chikungunya and dengue fever as well as local viruses such as La Crosse virus. Since 2020 the lab has been conducting statewide surveillance of mosquitoes in collaboration with the Illinois Department of Public Health (IDPH). This includes identifying every mosquito to species and testing them for West Nile virus, La Crosse virus, Jamestown Canyon virus, and Eastern Equine Encephalitis virus, as well as others. This work will lead to a major update to our knowledge of statewide presence and abundance of mosquito species diversity in the state.  

The research team is also conducting studies on: 

  • insecticide resistance in Illinois mosquito populations and the genetic mechanisms behind it; 
  • mosquito behavior and ecology, physiology, and immunology in the lab to better understand how resources in the landscape and climate change can affect vector-borne pathogen transmission;
  • the efficacy of different surveillance methods for vectors of concern and the use of novel traps and bait stations as a control method; 
  • the impact of vegetation on West Nile virus vector abundance, behavior, and infection; 
  • effects of climate change on mosquito abundance, physiology, and spread; and
  • mathematical models to optimize integrated control responses. 


Ticks harbor and transmit numerous pathogens that can make people sick, including the agents of anaplasmosis, babesiosis, ehrlichiosis, Heartland virus, Lyme disease, Rickettsia parkeri-rickettsiosis, Rocky Mountain Spotted Fever, and tularemia. Alpha-gal Syndrome (also known as the “mammal meat allergy”) is an emerging tick-associated disease of concern in Illinois that can cause allergic reactions to mammal meat and mammal byproducts.

Active tick surveillance

The INHS Medical Entomology Lab launched Illinois’ tick surveillance program in 2019, with support from the Illinois Department of Public Health (IDPH). INHS scientists actively collect ticks at selected sites around the state via dragging and traps per Centers for Disease Control (CDC) criteria and conduct special investigations after human tick-borne diseases are reported.

The program has already dramatically improved understanding of the geographic distribution of known ticks and tick-borne diseases in Illinois and has documented the presence of new disease-carrying ticks in Illinois. An online interactive map makes it easy for all Illinoisans to access the tick surveillance data and find out what ticks have been found in their area.

Medical Entomology Lab scientists also train staff from forest preserve and park districts, county health departments, and mosquito abatement districts to conduct tick surveillance, provide them with materials, and receive ticks from them for identification and testing.

Passive tick surveillance

Illinois Tick Inventory Collaboration Network (I-TICK) scientists identify ticks encountered and submitted by private citizens whose work or leisure takes them outdoors. The program seeks to better understand where and when ticks come in contact with people, pets, and livestock, and also examine what human activities affect the risk of finding a tick. I-TICK is a collaborative effort between the INHS Wildlife Veterinary Epidemiology Lab and the University of Illinois College of Veterinary Medicine. The INHS Medical Entomology Lab also offers a free tick identification service for Illinois residents and identifies ticks for health care and public health professionals who submit requests using the IDPH arthropod diagnostics form.


The INHS Fish Collection contains more than 890,000 catalogued specimens. Search the online database for invasive species.

The INHS Mollusk Collection contains over 485,000 catalogued specimens and is particularly strong in freshwater mussels, freshwater and terrestrial snails from the midwestern United States, and cone shells. Data from the mollusk collection can be searched online.

The Illinois Plants Database is an online resource that summarizes each Illinois plant species’ scientific name and taxonomic classification, distribution and occurrence records, trait and habitat data, and other information. The database also includes a photo gallery for each species.