Q-C arborists: Most area trees are surviving drought, insects

Q-C arborists: Most area trees are surviving drought, insects.
Despite invasive insects and drought conditions, trees in the Quad-Cities are healthy overall, and communities are working to keep them that way.
The biggest problem facing Davenport trees remains emerald ash borers, said city arborist Chris Johnson.
Though Moline has 535 ash trees, park operations manager Greg Johnson said the city hasn’t had any trouble with emerald ash borers.
Until he sees changes, he said he expects Rock Island’s trees to continue doing well and offer good canopy cover.
Broken branches, fallen limbs and other such tree hazards need immediate attention, he said.
Chris Johnson said drought also has affected Davenport trees, with some dying this year because of drought stress from the summer of 2012.
Chris Johnson said he expects some local residents will be surprised by how extensive the drought and emerald ash borer damage is in Davenport.
"I still talk to people on almost a weekly basis who have never heard of the emerald ash borer," he said.
"We’re trying to, obviously, replace trees," Greg Johnson said.

Fungi awake bacteria from their slumber

When a soil dries out, this has a negative impact on the activity of soil bacteria.
Using an innovative combination of state-of-the-art analysis and imaging techniques, researchers at UFZ have now discovered that fungi increase the activity of bacteria in dry and nutrient-poor habitats by supplying them with water and nutrients.
Once found, water and nutrients are absorbed and transported through the hyphae, allowing them to be supplied to parts of the fungal network in dry or nutrient-poor areas of the soil.
As part of their investigations, the researchers closely examined the transport of water, substrates and nutrients through the microscopically small hyphae of fungi.
The fungal hyphae had to pass through a dry, nutrient-free zone in order to grow through into a new area containing the culture medium.
In the experiment, these conditions were indeed improved by the growth of the fungi: "As the fungal hyphae grew through the dry zone, the bacterial spores germinated and we noticed clear microbial activity," says UFZ environmental microbiologist Dr. Lukas Y. Wick.
This study has given the UFZ researchers another important insight into fungi and their important function in soils.
This could be important specifically with regard to the impacts of climate change, if the ratio of dry to moist areas of soil dramatically increases," says Kästner.
"We want to carry out soil experiments under different environmental conditions and find out what influence fungal growth has on the breakdown of pollutants," says Wick.
Mycelium-mediated transfer of water and nutrients stimulates bacterial activity in dry and oligotrophic environments.

The drought is over, but now L.A. is being swarmed by bugs

The drought is over, but now L.A. is being swarmed by bugs.
Normally, the office gets about 25 phone calls a day; lately, it’s been around 80.
“They’re getting frustrated and maybe a little freaked out seeing so many insects around their home.” The majority of calls have been about two insects in particular: crane flies and fungus gnats.
Crane flies are sometimes called mosquito hawks or mosquito eaters.
The little black bugs that look like fruit flies are most likely fungus gnats, Sun said.
Though fruit flies and gnats aren’t closely related scientifically — flies are of the family Drosophilidae, gnats are Sciaridae — both are small, winged, black and irritating to find flying around your house.
Crane flies also flourish in damp conditions.
Sun said the best way to prevent fungus gnats is to make sure your yard is cleared of debris or leaves, so that the ground can dry quickly after it rains.
Both crane flies and fungus gnats are seasonal “nuisance insects,” according to Sun: They don’t spread diseases, and as we move closer to summer, you should be seeing a lot less of them.
4:45 p.m.: This article was updated with information about phone calls that the Greater L.A. County Vector Control District has received.

This small molecule could have a big future in global food security

Researchers at the University of Arizona have found a promising way to prevent the loss of millions of tons of crops to a fungus each year, offering the potential to dramatically improve food security, especially in developing countries.
The team’s approach uses transgenic corn plants that produce small RNA molecules that prevent fungi from producing aflatoxin, highly toxic substances that can render an entire harvest unsafe for human consumption even in small amounts.
Although extensive field testing will have to precede widespread application of the new technique in agricultural settings around the world, the results of the study, published in Science Advances, showed that transgenic corn plants infected with the fungus suppressed toxin levels below detectable limits.
Unlike in the U.S., where crops intended for human consumption are tested for aflatoxin and incinerated once levels approach 20 parts per billion (equivalent to one drop of water in a 22,000-gallon pool), no testing is available in many developing parts of the world, especially in Africa, where millions of people depend on consuming what they harvest.
The modified corn plants carry a genetic blueprint for small RNA molecules, each only about 20 base pairs long, only in the edible kernels, not the whole plant.
"The corn is constantly producing that RNA during the entire development of the kernel," Schmidt explained.
In their experiments, the team infected corn plants with Aspergillus and let them grow for one month.
The team took the project a step further and investigated overall gene expression in kernels to see if the transgenic corn plants come with undesired side effects.
This involved co-author Rod Wing’s laboratory, also of the UA’s School of Plant Sciences, to compare thousands of RNA transcripts between the nontransgenic control kernels and transgenic kernels.
"This corn plant would be like any other," she said.