California Ag Network

Tag: The Agricultural Research Service

  • Breeding Honey Bees for Adaptation to Regionalized Plants and Artificial Diets

    Honey bees could be intentionally bred to thrive on plants that are already locally present or even solely on artificial diets, according to a recent U.S. Department of Agriculture Agricultural Research Service (ARS) study.

    ARS researchers found individual bees respond differently to the same diet and that there is a strong genetic component involved in how they respond to nutrition. This points directly to the concept that managed bees can be intentionally bred to do better on different diets, whether you are talking about an artificial diet or a diet based on specific plants already growing in an area, explained lead researcher Vincent A. Ricigliano. He is with the ARS Honey Bee Breeding, Genetics, and Physiology Research Laboratory in Baton Rouge, Louisiana.

    “Urban development, modern agricultural systems and environmental alterations due to climate change, invasive plants, and even local landscaping preferences have all had a hand in regionalizing plants that dominate available pollen. It could potentially be more beneficial to tailor honey bees to do better on what is already available instead of working hard to fit the environment to the bees,” Ricigliano said.

    The overall aim would be breeding to improve nutrient use by managed honey bees, like we have done for poultry and cattle breeding programs, Ricigliano explained.

    “Now that we know there is room for genetic adaptation to diet, we could also look at breeding honey bees with improved nutrient efficiency or identifying genotype biomarkers that respond to various supplements to promote honey bee health,” he added.

    In most commercial apiaries, honey bees do not have the opportunity to naturally breed to adapt to local conditions because commercial beekeepers typically replace the queen in each colony every year. The queen in a colony is the only bee that lays eggs to produce the next generation.

    Beekeepers usually purchase new queens already inseminated from a handful of queen breeders in the United States. As a result, honey bees across the country generally have the same range of genes for nutritional responses without any specialized adaptation.

    Honey bees have already been successfully bred for a very few selected traits, among them Varroa mite resistance. Varroa mites are among the single largest problem afflicting honey bees in the United States today.

    “It was a little surprising to find when we started this study that, despite a sizable body of research pertaining to honey bee nutrition, relatively little is known about the effects of genetic variation on nutritional response,” Ricigliano said.

    His next step is to refine knowledge about what genes control which nutrient and metabolic pathways and where the greatest amount of genetic variation exists so that breeding plans can be specific and scientifically guided.

    The Agricultural Research Service is the U.S. Department of Agriculture’s chief scientific in-house research agency. Daily, ARS focuses on solutions to agricultural problems affecting America. Each dollar invested in agricultural research results in $17 of economic impact.

  • Disrupting One Gene Could Be First Step Toward Treating Honey Bee Parasite Nosema Ceranae

    BELTSVILLE, MARYLAND, June 20, 2019—Agricultural Research Service (ARS) scientists have taken the first step towards a weapon against the major honey bee parasite Nosema ceranae.

    There is currently no treatment for this parasite.

    The scientists found that feeding honey bees a small amount of an interfering RNA compound (RNAi) could disrupt the reproduction of N. cerana by as much as 90 percent in the laboratory study, according to a study recently published in Insect Molecular Biology.

    This RNAi compound targets a single N. ceranae gene called Dicer, explained Jay Evans, research leader of the ARS Bee Research Laboratory in Beltsville, Maryland, who headed the study.

    “Dicer is a critical part of Nosema ceranae’s machinery for defeating honey bees’ immune responses to infestation by these parasites. It also encodes an essential protein in N. ceranae’s reproduction. So, it could be a double-barreled, practical route for attacking N. ceranae. Even better, RNAi against Dicer is specific to the parasite and will not interfere with the health of the honey bees,” Evans said.

    In earlier studies, the lab had looked at attacking N. ceranea genes that encodes for proteins that make N. ceranae a better parasite such as a polar tube protein that is important in the invasion of bee cells by the parasite.

    “But by striking at a single gene that affects N. ceranae reproduction and the ability of this parasite to counter honey bee immunity, I think we may have found an even better—an excellent avenue of attack,” Evans added.

    But this is just the first step toward a possible treatment. The researchers need to prove the concept in the field and beekeepers’ apiaries.

    Nosema ceranae is widespread problem of honey bees, although the impacts on colony health remain unclear. The best measure of the damage of Nosema comes from Europe where this parasite has been linked to long-term colony declines in Spain.

    A chemical treatment had been available, but it was taken off the market due to production challenges.

    The Agricultural Research Service is the U.S. Department of Agriculture’s chief scientific in-house research agency. Daily, ARS focuses on solutions to agricultural problems affecting America. Each dollar invested in agricultural research results in $20 of economic impact.

    By Kim Kaplan