Silver nanoparticles + wormwood extract = new phytophthera fungicide

Phytophthera is a genus of fungi-like oomycetes (water molds) which can affect about 400 species of plants, including many agricultural, horticultural, and natural areas species.  The diseases can affect many different parts of the plants, causing blights, crown rots, root rots, stem rots, etc. Estimations worldwide are in the multibillion dollar range for crop loss due to Phytophthera diseases.  Phytophthera species have also developed resistance to many existing fungicides, and so researchers have been experimenting to find a new treatment plan.

Phytophthora root and crown rots (Phytophthora spp.) by Don Ferrin, Louisiana State University Agricultural Center, Bugwood.org

Sliver nanoparticles are, like they sound, really, really small pieces of silver.  The average size of a silver nanoparticle is 5-100 nanometers, which, to give you the an idea of size:

10 nm is the lower size of tobacco smoke particles
20-80 nm is the thickness of cell walls in some bacteria
50 nm is the size of the largest airborne viruses

Phytophthora root and crown rots (Phytophthora spp.) sporangia by Bruce Watt, University of Maine, Bugwood.org

Those sporangia are about 50,000 nm long; the largest silver nanoparticles are 50 times smaller!

Silver nanoparticles on their own seem to display antibacterial, antifungal, and antitumor activities and have been evaluated for use in everything from textiles to wound dressings.  There are several hypotheses as to exactly how the silver nanoparticles, primarily about their interaction with elements within the cells inhibiting enzyme and protein functions.

In the last couple of years, researchers have also found that wormwood (Artemisia absinthium) has antioxidant activity.  By combining the silver nanoparticles with the wormwood extract, researchers have come up with a product that is effective against several strains of Phytophthera and, due to the multiple ways that silver nanoparticles affect cells, there is little concern for Phytophthera developing resistance.

wormwood (Artemisia absinthium) by Chris Evans, Illinois Wildlife Action Plan, Bugwood.org

To read about the research: Researchers Find a “Silver Bullet” to Kill a Fungus That Affects More Than 400 Plants and Trees
Phytophthera Images: Phytophthera spp.
Wormwood Images: Artemisia absinthium

Not the avocados! Florida avocado crops under threat from invasive insect-disease duo

The number of avocado recipes seem to have exploded the last few years with the demise of the low-fat diet and the interest in the concept of "healthy fats."  Avocado on toast, eggs baked in avocados, vegan friendly avocado based puddings, and, of course, guacamole are just a few examples of the attention being paid to avocado.  Unfortunately, while the early 2000 were out with the low-fat diets it was also in with the redbay ambrosia beetle.  The redbay ambrosia beetle (Xyleborus glabratus), and it's accompanying fungus laurel wilt (Raffaelea lauricola), came into Georgia likely through infest hardwood pallets or packing material in 2002.  By 2005 it was found to be associated with the rapid decline in redbay (Persea borbonia) and sassafras (Sassafras albidum) in Georgia, Florida, and South Carolina.  So why are we talking about avocados?  Unfortunately, they are all part of the Lauraceae family of trees and once infected, the trees can be dead within six weeks.  While Florida only produces 10% of the avocados in the US, it is still a 64 million dollar industry and is being treated as a urgent threat to the overall crop.

Laurel wilt (Raffaelea lauricola) by R. Scott Cameron, Advanced Forest Protection, Inc., Bugwood.org

 The real concern for growers is that by the time the first signs of infestation by the beetle have shown up, it's already too late.  Finding trees that have been just infested mean that a fungicide can be used to save the tree.  So, what are researchers using to target infested trees?  Drones.  Drones carrying a thermal digital-imaging camera to find stressed trees. Once researchers have identified areas with stressed trees, then they send in the dogs.  Dogs will alert handlers when they find trees that are infested and targeted treatments can be applied.

redbay ambrosia beetle (Xyleborus glabratus) galleries in redbay tree by James Johnson, Georgia Forestry Commission, Bugwood.org

As wide as the beetle and fungus have already spread and as there are multiple hosts for this deadly duo, there isn't a practical hope for eradication and there is potential for the disease to spread to other avocado producing states, California being the most concerning.  While the disease can't be controlled in the natural areas of the states, there is the ability to use the tools researchers are coming up with to save avocado orchards.

Laurel wilt (Raffaelea lauricola) EDDMapS. 2015. Early Detection & Distribution Mapping System. The University of Georgia - Center for Invasive Species and Ecosystem Health. Available online at http://www.eddmaps.org/; last accessed May 5, 2015.

For more on the research on detection strategies: Florida turns to drones, dogs in race to save the guacamole

Redbay ambrosia beetle images: Xyleborus glabratus

Laurel wilt images: Raffaelea lauricola

BugwoodWiki Article: Redbay ambrosia beetle Xyleborus glabratus

EDDMapS: Laurel Wilt Distribution Map

Students Tackle Hydrilla Problem in NC

Fishing, a beloved hobby nationwide, is starting to become a little more involved than digging up some worms and heading out on your boat for an afternoon.  Aquatic invasive species are reproducing rapidly, completely out competing native vegetation in some areas and making it more difficult to even move a motorboat around a pond or river.  Hydrilla (Hydrilla verticillata) has taken over waterways in Edenton, NC and the students and community members have begun an information campaign and will put up cleaning tools to encourage boaters to clean their equipment to prevent further spread in the area.

Hydrilla (Hydrilla verticillata) tangled on a boat motor by Wilfredo Robles, Mississippi State University, Bugwood.org

If you spot hydrilla while out and about, don't forget to report it!  You can find the smartphone application for your area on the BugwoodApps website and download it before you head out.  Don't forget to include a picture with your report!


Want to know if it is in your area?  Hydrilla distribution map
More images of hydrilla?  Hydrilla certicillata
BugwoodWiki: Hydrilla

Community teams up to fight the spread of hydrilla

Lionfish Tournament Northeast Florida, All You Can Catch!

We've post a few times about the invasive lionfish issue in Florida waters, so now's your chance to jump on the bandwagon and, if you're lucky, win a prize! The Northeast Florida Lionfish Blast is taking place from May 1-31 and who ever catches the most lionfish in two days of diving can win up to $1,000 and a sport watch.

lionfish (Pterois volitans) by U.S. Geological Survey Archive, U.S. Geological Survey, Bugwood.org

If you happen to have your smartphone or tablet and catch a lionfish, don't forget to report it!  Check out the IveGot1 application for iPhone and Android and don't forget to include a picture of the lionfish when you report!

Lionfish Tournament Takes Aim At Invasive Species
To learn more about this competition: Northeast Florida Lionfish Blast

Aggressive Eradication Plan for Starry Stonewort in WI Lake

Starry stonewort (Nitellopsis obtusa) was found in Little Muskego Lake, WI last September.  After the Department of Natural Resources and concerned community members collaborated on the best plan for eradication, they are now ready to take action.   Next month, the three acre lake will be populated by trained divers searching for an plucking out the invasive algae.  In August, divers from a commercial company will take to the lake with a vacuum to rid the lake bottom of the algae.  While in more thoroughly invaded lakes, mechanical harvesting seems to have made the issue worse, spreading the plant around more so than removing it entirely, WI DNR is hopeful that it will prove effective in instances where the invasion is caught early.



To read more on the project: DNR, residents wage counterattack on invasive plant in Little Muskego Lake

From thousands to four? Pelicans scoop goldfish from Colorado lake

A few weeks ago, we posted about the goldfish problem in Teller Lake #5, Colorado.  They expected to either shocking the fish to collect them or even drain the lake.  Pelicans have save them the trouble of deciding a course of action.  When Colorado Parks and Wildlife personnel visited the lake on Tuesday to sample the lake, they came up with nary a goldfish.  Whereas a few weeks ago thousands could be seen in the lake, only four goldfish were observed from the boat.  While wildlife biologists had seen American white pelicans (Pelecanus erythrorhynchos) scooping the goldfish and had found some that had been regurgitated, they didn't expect such a reduction of the population.  Due to the fact that the remaining number of goldfish is so small and are expected to be finished off by the pelicans or the bass, Colorado Parks and Wildlife don't need to do anything else.  The "natural control" the pelicans provided may even lead to strategic placement of rehabilitated pelicans, an option which may be brought up at the next state aquatic biologists meeting.

American white pelican (Pelecanus erythrorhynchos) by Terry L Spivey, Terry Spivey Photography, Bugwood.org

The original article: Hungry pelicans credited with gobbling thousands of goldfish infesting Boulder lake
American white pelican images: Pelecanus erythrorhynchos

Nicotine a medicine for parasitized bumblebees

A medicine for ill bumblebees (Bombus terrestris) but a poison for healthy ones, researchers from Queen Mary University of London and Royal Holloway, University of London found that bumblebees infected with the trypanosome gut parasite Crithidia bombi preferred nicotine-laced nectar.  The nicotine had a benefit for infect bees: antimicrobial secondary metabolites which delayed the infection by a few days, though it didn't clear the infection entirely nor extend the overall life expectancy.  When healthy bees consumed nicotine-laced nectar for long periods reduced their life expectancy, an effect not observed in infected bees.

large earth humble bee (Bombus terrestris) by Whitney Cranshaw, Bugwood.org

To read about the research: Bumblebees use nicotine to fight off parasites
Images of Bombus terrestris: Bombus terrestris