gut

A fern-based insecticide

December 8, 2023 By EarthWise Leave a Comment

A spore-producing bacterium is the source of various crystal toxins (known as Cry proteins) that are widely used in modern agriculture to combat insect pests – generally caterpillars and other larvae – that attack important crops. Pest control in corn, soybean, and cotton use these insecticidal proteins for protection against major insect pests. The pesticides are obtained from Bacillus thringiensis (Bt) bacteria to produce the proteins.

Bt Cry proteins are secreted by the bacteria but are harmless to the bacteria. They are harmless until ingested by insects and are then activated by the alkaline environment in the gut of insects which is entirely different from the acidic environment of our own digestive systems. In the insect’s gut, the proteins become a powerful feeding inhibitor by breaking down the insect’s gut lining. Bt Cry proteins are considered safe for humans.

Researchers continue to seek alternative solutions because there are concerns that insect pests could develop resistance to these toxic proteins.

Researchers from two Australian universities have analyzed the structure of a novel insecticidal protein that could be effective in protecting essential crops. The protein is naturally produced by ferns including common houseplants like brake ferns.

The newly discovered proteins offer a different mode of action from the Cry proteins and therefore are a potential solution to the problem of pest resistance to existing insecticides. The new family of insecticidal proteins is designated as iPD113 and has been shown to be very effective against caterpillar pests of corn and soybeans.

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Discovery: ferns produce crop-saving insecticide

Photo, posted October 5, 2015, courtesy of Marianne Serra via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The Plight Of Monarch Butterflies | Earth Wise

April 20, 2022 By EarthWise Leave a Comment

The monarch butterfly is one of the world’s best-known butterflies and has become the symbol for a whole class of imperiled pollinators. Populations of the iconic orange-and-black insects have declined dramatically in recent decades.

According to the U.S. Fish and Wildlife Service, the eastern monarch population has dropped 88% between 1996 and 2020. Habitat loss, pesticide use, and global climate change are some of the factors driving monarch butterfly population declines.

According to a new study led by scientists at Emory University, monarch butterflies are also increasingly plagued by a debilitating parasite. The study, which was recently published in The Journal of Animal Ecology, reviewed 50 years of data on the infection rate of wild monarch butterflies by the protozoan Ophryocystis elektrosirrha (or O.E.). The research team found that the O.E. infection rate had increased from less than 1% of the eastern monarch population in 1968 to as much as 10% today.

The O.E. parasite invades the gut of monarch caterpillars. If the adult butterfly leaves the pupal stage with a severe parasitic infection, it begins oozing fluids from its body and dies. If the infection is lighter and the butterfly survives, it will not fly as well or live as long as uninfected butterflies.

The study found that one of the contributors to the rise in parasitism is the increased density of monarchs in places where they lay their eggs. The increased density may be due to several factors, including the loss of habitat, the widespread planting of non-native milkweed, and by people raising large numbers of monarchs in confined spaces.

If the infection rate continues to increase, monarch butterfly populations will likely continue to plummet.

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Monarch butterflies increasingly plagued by parasites

Plight of the Monarch

Saving The Monarch Butterfly

Photo, posted September 18, 2008, courtesy of Roy Niswanger via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Animals And Social Distancing | Earth Wise

June 16, 2020 By EarthWise Leave a Comment

As the spread of COVID-19 continues throughout the U.S. and around the world, health officials continue to ask people to keep physical space between themselves and others outside their homes. It’s an important and effective way to slow down and prevent the spread of disease.

But it’s not just humans who can benefit from social distancing. It turns out that animals can, too.

Microorganisms living on or inside our bodies are important for both our health and for the development of disease. Researchers from the University of Texas at San Antonio have found evidence for the importance of social distancing to minimize the spread of microbes among individuals. The researchers studied wild monkeys to find out what role diet, genetics, social groupings, and distance in a social network play when it comes to the microbes found inside the gut. The gut microbiome refers to all the microorganisms living in the digestive tract.

The research team studied the fecal matter of 45 female colobus monkeys that congregated in eight different social groups in a small forest in Ghana. The researchers observed major differences in gut microbiomes between the eight social groups. But individual monkeys from different groups that were more closely connected to the population’s social network had more similar gut microbiomes. The findings, recently published in the journal Animal Behaviour, indicate that microbes may be transmitted between monkeys during occasional encounters with other monkeys from different social groups.

Learning how microorganisms pass among monkeys can help researchers understand how diseases spread. Understanding how diseases spread can help guide decision making during this pandemic and any future disease outbreaks.

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Even animals benefit from social distance to prevent disease, research shows

Photo, posted January 10, 2007, courtesy of Silke Baron via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Microplastics And Humans

November 27, 2018 By EarthWise Leave a Comment

Microplastics are everywhere. The tiny plastic particles pose a massive environmental challenge. Microplastics are polluting oceans at an alarming rate. Much of the oceanic microplastics result from the breakdown of plastic litter. Another source of microplastics pollution is microbeads. Microbeads, which are commonly added to cleansing and exfoliating personal care products, pollute the environment when they get flushed down the drain.