But in the U.S., crossing state lines is free wheeling, according to researchers from the U.S., Australia and New Zealand, who evaluated the threat of invasive pests to states from within the country.
"We concluded that the immediate threat from known invasive insect pests is greater from within the United States than without," the researchers reported in the current issue of Nature Communications.
"Our findings have significant implications for biosecurity policy and the need to consider security measures beyond established national borders," said Matthew Thomas, professor of entomology, Penn State.
Alien invasive species cost the U.S. economy $120 billion annually. Determining the identity and potential entry paths for these species is important for farmers and policy makers, especially in light of the increases in global trade and transport of agricultural materials internationally.
The researchers, who included Thomas; Dean R. Paini, David C. Cook and Paul J. De Barro of CSIRO Ecosystems Science, Canberra; and Susan P. Worner, Lincoln University, Canterbury, New Zealand, looked at a large database comprising details for over 850 pest species across 459 different geographic locations around the globe to determine which insect species are normally found together. Insect pests do not assemble randomly, but come together based on shared ecological and environmental features. For example, two species that feed on citrus crops in sub-tropical environments might often be found together, but they are unlikely to share many features with a pest that attacks sweet corn in temperate environments. This approach of comparing different species assemblages enabled the team to generate lists of the top 100 known insect pests most likely to establish in the U.S. and each of the 48 contiguous states.
The researchers found that, while all the top 100 known exotic insect pests for the entire U.S. already exist in the country, the top lists for each of the states included many species that are yet to establish in those states. In all cases except one, the absent pests do occur somewhere else in the U.S. and more often than not, they are found in a neighboring state. In fact, 12 states had every pest species that they were missing located just across their borders in a neighboring state. The one exception is Florida, which is one of a few states to have a relatively unique pest assemblage, perhaps because of the tropical nature of its environment.
Insect pest assemblages are not necessarily the same across neighboring states. While New York, Pennsylvania, Ohio and Michigan form a cluster of similar species, so does Minnesota. However, Wisconsin does not, but shares a species assemblage more similar to Maine. The south is a solid block from Texas to Virginia, excluding Florida and including Missouri and Illinois. Farther west the Dakotas, Montana and Wyoming share pest profiles with Nevada, but Utah, Colorado and New Mexico are more like Nebraska.
The researchers used a computer approach called artificial neural networking -- a program that links information on branches like biological neurons -- to determine the interconnectivity of the pest assemblages across different sites. They searched an existing database, CABI Crop Protection Compendium, to identify the top 100 potential invasive insect pests for the entire U.S. and individual states. They then determined which species did not yet reside in these top 100 lists.
Thomas and his colleagues found that no relationship existed between the state's size and the number of potential pests still absent in the state. They also found that southern states with their increased biodiversity did not have fewer absent insect pests from their mix of potential pests. They did find significant negative relationships with both the number of incoming domestic air passengers and the gross national product of the state. States with higher gross national products had fewer missing potential insect pests and states with higher domestic air passenger traffic also had fewer absent potential insect pests.
"The fact that exotic species absent from one state were frequently found in a neighboring state implies the ease at which pests could arrive from a neighbor," said Thomas. "Fly into a U.S. airport from overseas and there are many biosecurity measures in place to reduce accidental introduction of a pest, weed or disease. Our analysis suggests the risks might be just as great flying into a domestic terminal or crossing a state boundary by car."
Australia's Cooperative Research Centres Program supported this work.
A'ndrea Elyse Messer | EurekAlert!
Forest Management Yields Higher Productivity through Biodiversity
14.10.2016 | Technische Universität München
Farming with forests
23.09.2016 | University of Illinois College of Agricultural, Consumer and Environmental Sciences (ACES)
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences