Feral honey bees offer tools for managed honey bee health

Honey bee. Photo:SDF

People have domesticated many different plant and animal species to utilize for food, fiber, or other resources. To domesticate a plant or animal people deliberately breed individuals that have valuable or desirable traits – big ears in corn, longer shelf life in vegetables, less fat (unfortunately) in pigs, large, dry flavorless breasts in chickens. The value and desirability of these traits are in the eye of the beholder.

Organisms cannot excel at everything. Breeding to enhance one trait inevitably diminishes another trait. This is called a trade-off and occurs in most domesticated plants and animals. Crops bred for greater yield often have lower resistance to pests and diseases. Animals often have the same problems; bred for rapid growth domestic pigs, chickens, cows often have lower immune function or resistance to disease.

Honey bees have been on the world stage for several years since beekeepers have experienced higher than normal colony losses. Despite all the attention and even affection honey bees have received many people are surprised to learn they are domesticated, exotic, animals just like other livestock. And, as with other domesticated animals, bees have been bred for traits such as honey production, overwinter survival, and easy handling.

A wild honey bee colony lives in the hole in this tree. Photo: SDF

As animals are domesticated the genetic diversity of the population often declines. Genetic diversity can help individuals and populations survive environmental stress and disease. In a new paper, Margarita Lopez-Uribe (former postdoc from the Tarpy, Dunn, and Frank labs now faculty at Penn State) and co-authors compared genetic diversity of feral and managed honey bee colonies. In a previous paper, Elsa Youngsteadt, Holden Appler and others reported that feral honey bees had greater immunocompetence than managed honey bees.

In the new paper, we looked to genetic diversity as a possible mechanism. Feral colonies had less genetic diversity than managed ones. However, transcription of immune related antimicrobial peptides increased as genetic diversity increased in feral colonies but not managed colonies. This suggests that the genetic diversity that does exist in feral bees, perhaps due to natural selection for optimal genotypes and immune variants, improves their immune function. Genetic diversity in managed colonies, from artificial selection for desirable traits, does not improve immune function.

Thus, there may be a trade-off between having bees with traits desirable to beekeepers and bees that can fend off the constant onslaught of diseases to which honey bees are subjected. Scientists and beekeepers are working from every angle to improve honey bee health and sustainability. They should look to feral bees, that survive in the wild without the pesticides and medicines used in managed colonies, for novel genetic variation that could improve disease resistance.

López-Uribe, M.M., Appler, R.H., Youngsteadt, E., Dunn, R.R., Frank, S.D., Tarpy, D.R. (2017) Higher immunocompetence is associated with higher genetic diversity in feral honey bee colonies (Apis mellifera). Conservation Genetics. doi:10.1007/s10592-017-0942-x

This study was funded by the CALS Dean’s Enrichment Grant from North Carolina State University (to DRR, SDF, and RRD) and a National Science Foundation (NSF) Postdoctoral Fellowship (1523817 to MMLU).

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    February 23rd, 2017|Categories: Uncategorized|Tags: |

    Warm days likely bring ambrosia beetle attacks

    Frass tooth-pick from adult ambrosia beetles boring into trees. Photo: SD Frank

    With several days of warm weather be on the look out for ambrosia beetles in your nursery. You are trapping right?

    Keep checking those traps. I already have reports of a few beetles trapped in the eastern part of the state. Do not over-water your trees. Media moisture over 50% makes trees more attractive to beetle attacks. Many species, like dogwood, are never attacked when media moisture is below 50%.

    Read up on our past ambrosia beetle posts, industry publications, new media moisture thresholds, and a review in the Journal of IPM.

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      February 21st, 2017|Categories: Uncategorized|Tags: |

      Protecting Pollinators in Urban Landscapes – Save the Date

      Two years ago Elsa Youngsteadt and I from NC State joined forces with Dave Smitley, Heidi Wollaeger, and others from Michigan State University to organize the first national conference related to pollinator conservation in ornamental plant production and urban landscapes. Over 150 people with jobs in research, extension, industry, government, or NGOs spent 3 days in the North Carolina mountains with a lineup of renowned international speakers.

      But this conference was not just about listening, it was also about talking and discussing pressing issues such as insecticide safety and habitat conservation. As you can imagine with such a diverse group of people with so many perspectives sometimes we talked louder than others. But that was the fun and enlightening part that made the conference unique.

      Folks studying bee conservation had dinner with folks from agrochemical companies. Extension folks trying to find real-world pest management solutions had beers with beekeepers and conservationists. I doubt most of these interactions would have ever happened without this conference.

      Well, the conference will return October 9-11, 2017 as the 2nd national conference on Protecting Pollinators in Urban Landscapes. This time in beautiful Traverse City, Michigan. We are still building the program so consider this a save the date. However, you can check out the program from last time to see the diversity of topics and quality of the speakers. If you really want to get out of your (research, conservation, extension, industry, beekeeper) bubble to hear and discuss the state of the art on a range of topics this is the conference for you.

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        February 15th, 2017|Categories: Lab Happenings, Pollinators, Uncategorized, Urban Ecology|Tags: |

        New Bee BMP Summary from HRI

        Photo: SD Frank

        The Horticultural Research Institute just released a pdf summarizing some BMPs for protecting pollinators from insecticides in greenhouse and nursery production and in landscapes. The crux of it is read the label and follow some basic IPM practices like using alternative management tactics. However, there is also good advice like do not drench ‘bee attractive’ plants with clothianidin, dinotefuran, imidacloprid, or thiamethoxam. And, avoid spraying plants with these products within 3 weeks of shipping. Find other information in a previous post highlighting resources from Michigan State and on the ecoipm Native Pollinator Site.

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          January 27th, 2017|Categories: Uncategorized|Tags: |

          As spiders leave the kitchen, pests keep cooking

          A spider in the family Anyphaenidae has made its home on a twig infested with scale insects.  Photo: Emily Meineke, Harvard University

          I think by now most people accept that we can’t hope to preserve all extant creatures over the next 50 or 100 years. Global changes in temperature and habitat will help some species and hurt others, as Elsa Youngsteadt showed in her recent paper. Since we can’t save every creature, what is really important to protect? Increasingly, people try to understand and protect species and ecological interactions that generate ecosystem services for people, rather than diversity per se.

          Former undergraduate researcher Anna Holmquist examines branches in the field. Photo: Emily Meineke, Harvard University

          Urban warming makes street tree temperatures similar to what is expected under climate change, so we have studied them to predict the effects of warming – urban and global – on pest abundance and tree health. Street trees also host a surprising amount of arthropod diversity if you just look hard enough. In a new paper, our former graduate and undergraduate students, Emily Meineke and Anna Holmquist, with help from Gina Wimp at GWU, studied the effects of warming on spider communities in street tree canopies.

          The team tested two predictions. Spiders like to eat and often become more abundant in places where prey is more abundant. So we predicted that, since heat increases herbivore abundance, spider abundance would follow. However, because some spiders probably benefit from warming while others do not, we predicted the composition (member species) of the spider community would be different in hot and cool trees.

          The fitness of this spider probably increases with warming since it is hot and sweaty from exercise and yoga. Other spiders (not pictured, you can only work kids so hard) die in, or leave, hot places. Thus, yoga spiders will be more common on hot trees and the community composition will change. Artwork by: I.F.

          Ghost spiders, like this one, are nondescript but perform important ecosystem functions. Photo: Matt Bertone, NCSU.

          Spiders were by far the most abundant natural enemy group. However, as herbivore abundance increased with warming, spider abundance stayed the same. This is bad news for trees because it means that herbivores can increase unchecked. Instead, urban warming altered spider community structure due in part to a whole family of spiders, Anyphaenids — aptly named ghost spiders – virtually disappearing from the hottest trees in one year of the study. This is bad news for conserving urban biodiversity and also because ghost spiders feed on particular pests like lace bugs.

          In this experiment, warming reduced biodiversity but also likely reduces biological control by predators, an important ecosystem service. Something happens in these trees to make a common ecological interaction – predators congregating to prey – stop happening. The consequence is that pests go nuts and trees suffer.

          Read the full paper here:
          Meineke, E.K., Holmquist, A.J., Wimp, G.M., Frank, S.D. (2017) Changes in spider community composition are associated with urban temperature, not herbivore abundance. Journal of Urban Ecology, 3 (1): juw010. doi: 10.1093/jue/juw010.

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            January 26th, 2017|Categories: Feature, Natural Enemies, Urban Ecology|Tags: , , , |

            Who wins and loses with warming? Where you live matters.

            Climate change is generally considered bad for people, earth’s biomes, and, of course, polar bears. But as the climate warms will all critters suffer? Will they all be affected the same way? No. In addition to the losers who slowly fizzle out under the oppressive heat, there will be winners who benefit from warming.

            An animal’s response to climate change depends largely on two things: the amount of warming in a habitat and the physiological limits of the animal. It has been shown pretty convincingly that animals closer to the equator are more sensitive to warming than animals farther north. I know what you are thinking, “but tropical animals are hot all the time, they should be used to it.” I thought the same thing, but how it works is that since they are hot all the time, they live close to their thermal limits. So for animals in hot places, a little more heat pushes them over the edge.

            Therefore the biological effects of climate change are expected to vary geographically, particularly for ectothermic animals such as insects. Elsa Youngsteadt and other folks in the lab took a road trip to test the hypothesis that insects at high latitudes, where it is cold, should generally benefit from warming whereas insects at low latitudes should have mixed responses: some should benefit, but others should be pushed over their thermal limits.

            In a brilliant new paper Elsa reports her findings from this trip. The team sampled insects from street trees in the hottest and coolest parts of four cities–Raleigh, Baltimore, Queens, and Boston–taking advantage of the urban heat island effect as a natural warming experiment.

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            Four cities at different latitudes were chosen to study warming effects on insect communities. Background map from the National Biomass and Carbon Dataset.

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            One of the authors, Andrew Ernst, takes measurements at a typical study tree. Photo: E.K. Youngsteadt


            In the lowest latitude city, Raleigh, some taxa became more abundant with warming while others declined. This suggests that, although some species benefited from warming, just as many species suffered. In the coldest and highest latitude city, Boston, most insect groups were unaffected or became more abundant, suggesting that warming was good for most species living in a frigid northern metropolis. Just as predicted! This doesn’t happen very often.

            stickycard

            Yellow sticky cards were used to sample insect communities in urban trees. Photo: E.K. Youngsteadt.

            It seems good that not all taxa tank in Raleigh–but the fact that some benefit and others decline could be ecologically disruptive, too: Maybe a parasitoid and its host respond differently, or a predator and its prey. This sort of mismatch could lead to extinction of higher trophic levels if the prey does poorly, or herbivore outbreaks if the predator fails.

            I’ll warn you upfront, this paper is dense and there are probably a lot of new concepts packed in that most people will need time to unpack. However, capturing the response of a whole community to a couple degrees of warming is novel and worth the read. Think about the responses of your favorite organisms. Not just in cities but across the globe.

            Read the paper here.

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              December 16th, 2016|Categories: Urban Ecology|Tags: , , , |

              iBook for Greenhouse Pest Identification

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              The 2nd Edition of “Insect and Mite Pests of Floriculture Crops: Identification Guide” by Matt Bertone, Steven Frank, and Bryan Whipker is now available from iTunes. This guide is designed so growers, extension personnel, or anyone else can identify common arthropod pests on greenhouse crops.

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              This new edition covers aphids, fungus gnats, leafminers, mealybugs, mites, scales, shoreflies, thrips, and whiteflies. Concise biology and management information is paired with galleries of fantastic photographs by Matt Bertone.

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              Galleries feature multiple views of the pests, their damage, and their natural enemies. The final edition will be out in 2017. And guess what? Its free so download it now! Thanks to a grant from the Fred C. Gloeckner Foundation.

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                November 10th, 2016|Categories: Greenhouse IPM|Tags: , , |

                New resources for protecting pollinators in urban landscapes

                Dr. David Smitley at Michigan State University helps organize the national Protecting Pollinators in Ornamental Landscapes Conference that took place in 2015 in North Carolina and will be held again in Michigan in October 2017.

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                Dr. Smitley passed along a new bulletin and article on this topic.  Dr. Smitley also provided a PowerPoint presentation titled “Update on Neonics, Bees and Best Management Practices for Protecting Pollinators and Beneficial Insects On Ornamental Plants” that he presented a couple weeks ago at the Ornamental Workshop in Henderson, NC.

                 

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                  November 9th, 2016|Categories: Pollinators, Urban Ecology|Tags: |

                  Highlights of the 20th Ornamental Workshop

                  Frank Hale and Andrew Loyd in costume (not mandatory btw) during the Wednesday night social. Photo: Suzanne Wainwright-Evans.

                  Frank Hale and Andrew Loyd in costume (not mandatory btw) during the Wednesday night social. Photo: Suzanne Wainwright-Evans.

                  Now over 40 years old, the Ornamental Workshop convened for three beautiful days in late October. One hundred and twenty-three university researchers, extension personnel and representatives from agrochemical companies, biological control companies, tree care companies, public gardens, and others all converged in Hendersonville, NC to geek-out on the pests and diseases of ornamental plants.

                  Engaged participants soaking up knowledge.

                  Engaged participants soaking up knowledge. Photo: Suzanne Wainwright-Evans.

                  Our keynote speakers, Adam Dale (University of Florida) and Steve Oak (USDA FS), started big with presentations about how climate change and urbanization affect insect and disease biology and management. For the next 3 days we had talks and workshops on everything from the latest research on exotic pests like emerald ash borer, crape myrtle bark scale, sudden oak death, and rose rosette, to new innovations in extension delivery. We covered nurseries, greenhouses, chemical control, biological control, new pests, old pests, you name it. We even had a workshop on macrophotography by Matt Bertone (NCSU). You can view the whole program to see what you missed.

                  Participants Cliff Sadof, Brian Kunkel, Gerald Adams, and Carlos Quesada 'networking' on a hike.

                  Participants Cliff Sadof, Brian Kunkel, Gerald Adams, and Carlos Quesada ‘networking’ on a hike. Photo: Suzanne Wainwright-Evans.

                  Of course we never work too hard at the Ornamental Workshop even though ‘work’ is in the name. Each night we gather for drinks and snacks for networking (there is that ‘work’ again) and catching up with friends. The highlight for some folks is Wednesday when we take the afternoon off for a mushroom foray and hiking. This naturally inspires some to attend the social Wednesday evening dressed as their favorite insect or disease. This without a costume can decorate a moonpie to honor their favorite pests.

                  Moonpie insects and diseases ready to be judged. Photo: Suzanne Wainwright-Evans

                  Moonpie insects and diseases ready to be judged. Photo: Suzanne Wainwright-Evans

                  I personally thank all the participants and sponsors for another great workshop. If you want to attend in 2018 watch the website, Facebook page, or join the listserv. If you know someone who should attend this meeting please pass along this post.

                  Morning at the Ornamental Workshop. Photo: SD Frank.

                  Morning at the Ornamental Workshop. Photo: SD Frank.

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                    November 9th, 2016|Categories: Landscape IPM, Nursery IPM|Tags: |

                    New paper: Urban warming reduces aboveground carbon storage

                    This is a guest post from our former student (now postdoc at Harvard) Emily Meineke.

                    Through years of studying urban trees and the insects that eat them, we, the Frank lab, have discovered that warming in cities leads to more pests. We also know how: where it’s warmer, insects survive and reproduce better, and the effects of their natural enemies are diminished. In most conversations we have about this work, explaining these discoveries leads to the question: but what does this mean for the trees?

                    Street trees perform essential services like removing pollutants from air. Photo: EK Meineke

                    Street trees perform essential services like removing pollutants from air. Photo: EK Meineke

                    I tackled this question with the help of Elsa Youngsteadt by studying how warming and pests affect tree drought stress and functions like photosynthesis and stomatal conductance. Of course, as in my previous work, I studied the charmless but interesting oak lecanium scale on willow oaks which are among the largest and most common street trees in Southeastern cities.

                    Oak lecanium scales on willow oak. Photo: EK Meineke

                    Oak lecanium scales on willow oak. Photo: EK Meineke

                    Over three years we took hundreds of tedious measurements (thanks Elsa!) to figure out how fast our trees were growing and thus how much carbon they were removing from the air and storing in their tissue. This is called carbon sequestration and is a critical way trees reduce carbon pollution and global warming.

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                    Elsa measuring photosynthesis. Photo: EK Meineke

                    In a new paper, we show that the urban heat island effect significantly reduces street tree growth. This is because trees in warmer urban areas photosynthesize less. When these effects were scaled up to all the willow oak street trees in Raleigh, warming reduced citywide carbon sequestration by 12%. However, insect pests like scales and spider mites had minor effects on tree growth compared to warming, at least in the short term.

                    Oak spider mites damage leaf cells and reduce photosynthesis. Photo: EK Meineke

                    Oak spider mites damage leaf cells and reduce photosynthesis. Photo: EK Meineke and A Ernst

                    These results lead to several recommendations for urban forest management. First, because urban and global warming are becoming more intense, urban trees will store even less carbon in the future. However, managers may be able to reduce these effects by planting trees that are more tolerant of hot urban conditions. This highlights the need for research to identify what trees are appropriate to plant in hot urban environments. In general, this research makes us excited about science that will help landscape designers tailor green infrastructure for resilience to climate change and intensifying urbanization.

                    Our results also highlight the utility of cities as large-scale natural climate experiments, in which sessile organisms, such as trees and many insect herbivores, are confined to different thermal environments in close proximity. The range of urban warming they experience parallels the extent of global warming expected regionally, outside the city, over the next several decades. Therefore, cities can serve as experiments that allow scientists to address questions that are otherwise difficult or impossible to approach, such as the effects of warming on mature trees.

                    Meineke, E.K., Youngsteadt, E.K., Dunn, R.R., Frank, S.D. (2016) Urban warming reduces aboveground carbon storage. Proceedings of the Royal Society – B 283: 20161574 DOI: 10.1098/rspb.2016.1574

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                      October 7th, 2016|Categories: Urban Ecology|Tags: , , , , |