from Predators:

Researchers Look for

Small Control Organism

Science (June 21, 2010) — One way to keep from getting eaten is to run. But recent research at the University of Guam’s Western Pacific Tropical Research Center shows that sometimes it’s better to just hide.

“The small size of an alien insect that feeds on a native tree from the western Pacific island of Guam allows it to hide in cracks and other locations that are out of reach for its only local natural enemy,” said UOG entomologist Aubrey Moore.

Moore has teamed up with UOG ecologist Thomas Marler to study the relationship between the native cycad tree, known as “fadang” in the Chamorro language, and a minute alien insect pest called cycad aulacaspis scale (CAS). The pest arrived on Guam in 2003, and then spread to Rota 50 miles north and Palau 800 miles southwest of Guam. The pest has killed 90% of Guam’s wild cycads. Findings about the ability of CAS to go undetected in secretive locations on cycad plants were published by Marler and Moore in the May issue of the journal HortScience.

The researchers have been interested in using biological control efforts to save the native fadang populations on Guam, Rota, and Palau. A predatory lady beetle that feeds on CAS was introduced to the three islands to control the pest. “Our initial Guam release was in early 2005 and the beetle established quickly and appeared to be doing a good job of controlling the scale insects by preying on them,” said Moore. But then a second epidemic outbreak of the scale pest occurred in late 2008 on Guam and early 2010 on Rota. Ecologists call this type of population behavior an “irruption” and it was this secondary increase in the pest population that caught the attention of the researchers.

“We wanted to know how the insect pest population could increase to such a serious threat level after the initial threat was brought under reasonable control by the predatory beetle,” said Marler. When some of the tiny insects find a hiding spot where they can feed and make babies without fear of being eaten by the beetle, all it takes for a sudden increase in the pest population is for the beetles to migrate away from the area after they run out of accessible scale insects.

The HortScience article also explains a more insidious outcome of this ability to hide. Cycads are valuable landscaping plants. Many species of cycads are susceptible to the pest, and the out-of-sight crannies on the plants can harbor a few undetectable scale insects. “We believe this is one of the reasons the insect has been so successful in spreading throughout many countries in recent years, as visual inspection of imported plants cannot detect the hiding insects,” said Marler.

Most programs for control of a pest that causes major agricultural or ecological damage do not rely on a single biological control organism. So the Guam team is making plans to introduce a second natural enemy of CAS. They contend that the findings about the secretive nature of the scale pest help inform what sort of natural enemy is needed on Guam and Rota. “Our work has shown that we need to find a biological control organism that is small enough to follow CAS into its tiny hiding places,” concluded Moore.

Sourced and published by Henry Sapiecha

LED Color to Grow Plants?

Nabesei Co Ltd, a company specializing in electronic parts, exhibited plants grown under LED lights in three different colors at an exhibition that took place from April 15 to 17, 2009, in Tokyo.

Plants of the same size were continuously irradiated with light from a lighting device equipped with 630nm red LEDs, a device with 430nm blue LEDs and a pink-colored LED light composed of half red LEDs and half blue LEDs.

After three weeks of irradiation, the growths of the plants were compared with one another. As a result, it was discovered that the pink LED light most effectively promotes the growth of plants, the company said.

According to Nabesei, plants do not need all wavelengths in the visible light range for their growth, but they absorb light with certain wavelengths to grow. For example, when they perform photosynthesis or come into bloom, red light around a wavelength of 660nm, which is the absorption peak for chlorophyll, promotes the growth. Meanwhile, when the plants form flower buds, blue light around a wavelength of 450nm promotes the growth.

When comparing the plants under the three kinds of light, those under the red LED light grew slower than others and were smaller as a whole. The plants under the blue LED light had fewer leaves and were spindly on the whole. On the other hand, the plants under the pink LED light had larger leaves and had generally grown in a more balanced way.

However, the wavelength ranges that affect the growth of plants are slightly different depending on the plant type. Therefore, field tests to evaluate the irradiation time and other issues should be conducted at agricultural experiment stations from now on, Nabesei said.

INCANDESCENT LIGHT GLOBE

In line with the ban on the sale of incandescent bulbs in 2012, the company plans to focus on the application of LEDs to illumination equipment for growing chrysanthemums. The irradiation of red LED light can delay the formation of buds on chrysanthemums. Moreover, LED light keeps bugs away because the LED emission spectrum is deviated from the bugs’ visibility curve.

In addition, Nabesei exhibited a completely watertight LED light in a tank. The product is also available in a bendable type, which is suitable for interior lighting and plant cultivation requiring water sprinkling, the company said.

Sourced and published by Henry Sapiecha 1st JULY 2009

WASHINGTON (UPI) — The U.S. Environmental Protection Agency has revoked all regulations permitting small amounts of the residue of carbofuran in food.

The EPA’s Monday decision was hailed by the American Bird Conservancy as marking “a huge victory for wildlife and the environment.”

The action involves a pesticide sold under the name “Furadan” by the FMC Corp. The EPA said the toxic insecticide does not meet current U.S. food safety standards. The EPA said its ruling will eliminate residues of carbofuran in food, including imports. Ultimately, the federal agency said, it will remove the pesticide from the market.

The conservancy said the agency’s announcement confirms a proposed action first announced in July. FMC Corp. will have 90 days to challenge the decision. Once the rule becomes final, the EPA will proceed with the cancellation of registration for all uses of the pesticide.

“Carbofuran causes neurological damage in humans, and one of the most deadly pesticides to birds left on the market,” said George Fenwick, president of the conservancy. “It is responsible for the deaths of millions of wild birds since its introduction in 1967, including Bald and Golden Eagles, Red-tailed Hawks and migratory songbirds. This EPA decision marks a huge victory for wildlife and the environment.”

The EPA said it was encouraging growers to “switch to safer pesticides or other environmentally preferable pest control strategies.”

Copyright 2009 by United Press International

Sourced and published by Henry Sapiecha 18thn May 2009

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Sourced and published by Henry Sapiecha 13th May 2009

MINNEAPOLIS (UPI) — U.S. scientists say they’ve developed a technique for modifying plant genes that could help provide sustainable food, fuel and fibre supplies.

Researchers at the University of Minnesota and Massachusetts General Hospital said their genome engineering tool can make a model crop plant herbicide-resistant without significant changes to its DNA.

“It’s still a (genetically modified organism), but the modification was subtle,” said Professor Daniel Voytas, lead author of the study and director of the university’s Center for Genome Engineering. “We made a slight change in the sequence of the plant’s own DNA rather than adding foreign DNA.”

Voytas said the technique has the potential to help scientists modify plants to produce food, fuel and fiber sustainably, while minimizing concerns about genetically modified organisms.

The scientists said they created a customized enzyme called a zinc finger nuclease to change single genes in tobacco plant cells. The altered cells were then cultured to produce mature plants that survived exposure to herbicides.

“This is the first real advance in technology to genetically modify plants since foreign DNA was introduced into plant chromosomes in the early 1980s,” Voytas said. “It could become a revolutionary tool for manipulating plant, animal and human genomes.”

The research was published online by the journal Nature.

Copyright 2009 by United Press International

Sourced and published by Henry Sapiecha 11th May 2009