Pacific Nut Producer Magazine

Tag: ARS

  • Buzzing Spring Pollinator Plays Significant Role in Almond Industry

    The USDA’s Agricultural Research Service (ARS), in collaboration with the Ecological Forestry Applications Research Centre in Spain and North Dakota State University, conducted a comparison of the physiological and molecular processes involved in the summer and winter dormancy of Osmia lignaria, also known as blue orchard bee or orchard mason bee.

    This analysis of gene expression is believed to be the first to compare the dormancy periods of this species in their natural habitat, and more importantly, it led to sequencing the first draft genome of this important pollinator for the almond industry.

    According to the U.S. Forest Service, North America has 140 species of Osmia. Osmia lignaria, a solitary bee, follows a one-year lifecycle that includes two periods of dormancy. During summer, the bee develops to the prepupal stage (the stage of larva after its final molt), pauses, then finishes to developing to the adult stage before winter. Adult bees slow their metabolic activity while overwintering [second dormancy]. When spring arrives, adult bees emerge from dormancy and become highly active in pollination. Although this species does not produce honey, it is very effective in pollinating almond trees due to cross-pollination among different varieties, which leads to higher crop yields.

    “This species inhabits a wide latitudinal range in North America, with populations in the north having different developmental rates and lengths of dormancy periods than those in southern populations,” said Alex Torson, a computational biologist with ARS’ Insect Genetics and Biochemistry Research in Fargo, North Dakota.

    “In the future, we can use the genome presented in this study to start comparing the genomes of individuals from these different geographic populations. If these differences in development and dormancy can be traced to their genetics, then we could develop managed populations from different geographic locations, and time the characteristics of those populations with peak floral blooms for different types of crops.”

    By aligning their emergence with the timing of crops, it would allow for better management and pollination, as this bee species emerges in the spring and is a significant pollinator of almond trees due to how it pollinates.

    Understanding how this lifecycle occurs has become increasingly important due to changes in environmental conditions. A better understanding of the evolutionary relationships among populations of this species will be critical for developing managed populations we can use for pollination services.

    The study is available in Insect Biochemistry and Molecular Biology.

    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 U.S. agricultural research results in $20 of economic impact.

  • Winter Honey Bees Show Resistance to a Common Insecticide

    Winter honey bees, compared to newly emerged summer bees, have a better ability to withstand the harmful effects of a widely-used insecticide in pest management, according to a recent study published in Apidologie.

    Honey bees feed on imidacloprid during a cage experiment. (Photo by Mohamed Alburaki, ARS)

    United States Department of Agriculture (USDA), Agricultural Research Service (ARS) researchers from the Bee Research Laboratory in Beltsville, Maryland, found winter honey bees’ consumption of a nearly lethal, imidacloprid-laced syrup did not affect their survival during the study.

    Imidacloprid is an insecticide made to mimic nicotine and is toxic to insects. This powerful insecticide is widely used in agriculture for pest management control. Honey bees are likely to encounter imidacloprid while foraging in the field or through contaminated hive products.

    “Although imidacloprid toxicity to honey bees is an important concern for beekeepers, our results provide good news,” said Miguel Corona and Mohamed Alburaki, researchers at the ARS Bee Research Laboratory. “Our research shows that winter honey bees have unrecognized physiological mechanisms to counteract the effects of insecticides.”

    The study assessed differences in diet behaviors for summer and winter honey bees in a controlled laboratory setting. Researchers provided sublethal doses of the imidacloprid-laced syrup to bees as necessary. Winter bees showed a preference to consuming imidacloprid-laced syrup over untreated sugar syrup while summer honey bees made the safe choice and avoided consuming the laced syrup each time.

    According to Corona, it is important to study the differences of summer and winter honey bees’ diets.  Honey bee colonies survive extreme seasonal differences in temperature and forage by producing two seasonal phenotypes of workers: summer and winter bees. These seasonal phenotypes differ significantly in their psychological characteristics as well as their susceptibility to disease and ability to handle poisonous substances.

    “Winter bees and summer bees undergo physiological changes to cope with drastic seasonal changes in temperature and the availability of nutritional resources,” said Corona and Alburaki. “Our results suggest that long-lived winter bees are especially well-adapted to tolerate higher levels of chemical stressors.”

    Corona said that although the study’s results show that winter bees could tolerate more intoxication by imidacloprid, they are still susceptible to higher concentrations of this insecticide in field settings. — By the USDA-ARS

  • Scientists Bring in Arch Enemy to Deal With Brown Marmorated Stink Bug

    A tiny wasp may be the solution for managing an agricultural pest causing major economic damage to fruit, vegetable, and field crops in North America and Europe.

    A female samurai wasp (Trissolcus japonicus) emerges from a brown marmorated stink bug (Halyomorpha halys) egg. (Photo by Elijah Talamas)

    Agricultural Research Service (ARS) scientists are currently studying Trissolcus japonicus, commonly known as the samurai wasp, to see if this parasitoid wasp is the right biological control agent for reducing brown marmorated stink bug (Halyomorpha halys) (BMSB) populations outside of Asia.

    Biological control is the process of reducing or mitigating pests or pathogens by using the pest’s or pathogen’s natural enemies. The samurai wasp is a known natural enemy for the BMSB in Asia, and researchers are understanding how it behaves in non-native environments.

    At the ARS Beneficial Insects Introduction Research Unit in Newark, DE, researchers are observing the behaviors of both quarantined samurai wasps from Beijing and local wild populations. They found these wasps have a strong preference for parasitizing BMSB’s eggs.

    “Parasitic wasps have the amazing ability to detect kairomones [chemical substances emitted by one organism and detected by another organism] that are left on surfaces or in the air of their hosts,” said Dr. Kim Hoelmer, research entomologist and research leader at the Beneficial Insects Introduction Research Unit.

    “In the field, when a female samurai wasp looks for evidence of her host in the environment, she can detect her host’s kairomones left on a leaf’s surface. The wasp increases her search when she detects the kairomones and that increases her probability of finding the host.”

    The research shows promise in that samurai wasps prefer their natural hosts’ eggs over those of other species.

    This finding does not surprise researchers since it is common for parasitoid wasps to have close relationships with their hosts.

    “The more intimate the relationship is, the better parasitoid wasps are as biocontrol agents,” said Dr. Matt Buffington, research entomologist with the ARS Systematic Entomology Laboratory, located in the Smithsonian National Museum of Natural History in Washington, DC.

    The tiny size of the samurai wasp (Trissolcus japonicus) is apparent from this dime, which has several of the insects sitting on it. (Photo by Ashley Colavecchio)

    Buffington and postdoctoral ARS scientist Elijah Talamas were instrumental in correctly identifying the samurai wasp from other Trissolcus species.

    “Parasitoid wasps play major roles in population regulation [of pests]. With this one species, we can explain how biological control works in our environment,” said Buffington.

    But do samurai wasps exhibit the same behaviors in the wild?

    In addition to laboratory studies, researchers are observing samurai wasps in natural environments, such as orchards and crop fields, where the BMSB is present. These wasps are adventive in North America, meaning they arrived accidentally without any human aid.

    At the ARS Appalachian Fruit Research Station in Kearneysville, WV, researchers are studying how samurai wasps reduce BMSB populations across a landscape. The research aims to determine if samurai wasps can survive in areas with other agricultural factors such as pesticides.

    According to research entomologist Dr. Tracy Leskey, BMSB populations can disperse and develop in areas outside of orchards and crop fields. The stink bugs constantly reinvade new areas, called wild host habitats, for survival.

    “We hope that samurai wasps can reduce those populations in wild host habitats, so we have less pressure in our agricultural areas,” said Leskey.

    The wasp is tiny; approximately 1.5 mm or the size of a sesame seed.

    Even though the samurai wasp shows promise as a biological control agent, researchers must follow a rigorous process to ensure that the samurai wasp’s impact is limited to its host and is not a threat to animals, humans, and crops.

    ARS researchers are in the process of requesting a permit for quarantined samurai wasps from Beijing to be approved for field release. Currently, wild populations of the samurai wasp are in 14 states. The permit would allow states without wild populations to use the wasp as a biocontrol agent for managing their BMSB populations. In addition, the permit would allow states with existing wild populations to introduce new samurai wasps in their management efforts.

    BMSB has been detected in 47 states and four Canadian provinces. BMSB is responsible for crop damage costing millions of dollars each year. This pest is also causing agricultural damage abroad after its infestation in European countries.

    Researchers from other ARS laboratories are also studying the samurai wasp, including the Invasive Insect Biocontrol & Behavior Laboratory in Beltsville, MD, Southeast Watershed Research Laboratory in Tifton, GA, Horticultural Crop Research Laboratory in Corvallis, OR, Sino-American Biological Control Laboratory in Beijing, China, and USDA-ARS European Biological Control Laboratory in Montpellier, France. – By Jessica Ryan, USDA ARS Office of Communications

  • 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.

  • Protecting Pecans with Friendly Fungi

    On July 1, 1930, the Agricultural Research Service (ARS) formally began its pecan research and breeding program in Austin, TX. With this support from ARS scientists, the United States became the world’s leading producer of pecans, a crop estimated to be worth over $560 million.

    Nearly a century later at the ARS Fruit and Tree Nut Research Station in Byron, GA , team members David Shapiro-Ilan, Fernando Vega, Tshima Ramakuwela (visiting Borlaug Fellow), and collaborators from Fort Valley State University and University of Georgia continue to build upon this legacy by developing newer and smarter ways to protect this beloved crop.

    According to their research, fungi that can naturally disable or eliminate insects may be key to protecting pecans’ future. Shapiro and his team identified two particularly “friendly fungi,” Beauveria bassiana and Metarhizium brunneum.

    Although harmless to humans, both fungi have shown an ability to effectively control economically damaging insects like pecan weevils, aphids, and stink bugs. There also appears to be a positive correlation between the presence of those fungi and the growth of the plants they’re applied to, leading to increased plant height, number of leaves, and root length.

    “For growers and consumers interested in organically grown pecans, this is an exciting finding,” said Shapiro. “More than ever, conventional pesticides are discouraged because of the chemical residues they leave behind that can hurt not only nontarget organisms, but also the overall environment. Fungi like B. bassiana, on the other hand, are naturally occurring, relatively widespread, and safe for people and plants. This is a big step in ensuring the productivity, profitability, and environmental sustainability of U.S. pecan production.”

    In conventional agriculture, crops are typically sprayed with chemically formulated pesticides. Insect-killing fungi such as B. bassiana and M. brunneum can also be sprayed using most standard agricultural equipment. However, fungi like B. bassiana are also endophytes – meaning they can live within the tissues of a host plant. Because of this characteristic, B. bassiana can coexist with and offer protection to pecan plants at the earliest stages of growth. The fungus is applied via a relatively simple inoculation process.

    There are several different approaches that even home gardeners or noncommercial pecan tree growers can replicate, said Shapiro. For example, a pecan seed can be rolled in fungus-spore powder or soaked in a fungus-spore solution. If the pecan plant has already sprouted into a seedling, drenching the soil around it with a high concentration of the fungus or spraying the leaves with the spores will also inoculate the crop. The protection provided by the inoculation can last as long as 3 years, which may be critical to ensuring the plants reach pecan-producing maturity.

    Beyond their potential as biopesticides and organic growth promoters for pecans, B. bassiana and M. brunneum have also successfully defended plants and people from threats like fungal diseases and pests such as mites, bedbugs, and mosquitoes. ARS continues to investigate the additional benefits of endophytes to pecan trees and other crops. – By Georgia Jiang, USDA-ARS Office of Communications