Don’t fret over (a few) dead bees

Dead carpenter bee. Photo: SDF

In spring carpenter bees, Xylocopa virginica, begin emerging from their winter hibernation. Many people are not concerned about dead bees but instead become alarmed when swarms of live carpenter bees are zooming around a wooden park bench or deck. Many young adult bees hibernate in a single burrow and a good structure may have many burrows. Male bees tend to come out first and swarm around waiting for female bees to come out. It can be intimidating but the males are harmless.

Other people worry about dead bees. Especially now since there has been so much

Dead bee below the fence where it spent the winter. Photo: SDF

press about pesticides, climate change, urbanization, and diseases that can threaten bee populations, a dozen or so dead bees on the ground could raise concern. This was the case yesterday when someone sent pictures of dead carpenter bees on their deck to a list serve I am part of. Dave Shetlar (Bugdoc Dave) from Ohio State University sent a quick response that is was natural for some bees to die over winter. The live bees just push them out onto the ground.

On the way home from work yesterday I found my own dead carpenter bee below a burrow in an old wooden fence. So I took some pictures and read up on carpenter bees in a great old review. Spring is here and carpenter bees are emerging from their burrows, dead or alive.

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

    Get ready for oak felt scales

    Oak eriococcin scale eggs spill out after removing the white cover. Photo: SDF

    We have written before about felt scales on oak trees. Oak eriococcin scales, Eriococcus quercus, are one of the earliest scale insects to produce eggs, and thus crawlers, in Raleigh. The females become felted and swell in early spring. Now they are full of eggs. When the crawlers hatch from the eggs is when horticultural oil applications would be most effective. Not much is known about other control tactics for this pest. Just be careful. An important scale predator looks very similar to felt scales and mealybugs. Larvae of scale-eating lady beetles in a couple related genera including Hyperaspis spp. are white and waxy. However, they move. Since scales don’t move these lady beetle larvae have to crawl around looking for food. Sometimes thousands of lady beetles hatch at once so please do not confuse them with scales.

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      March 22nd, 2017|Categories: Uncategorized|Tags: |

      New paper – Drought and heat benefit tree pests

      It’s not easy for trees to grow, much less, thrive in cities. Cities are warmer than natural areas where trees evolved. City soil is typically drier than natural soil too. Both of these problems – heat and drought – are caused in large part by impervious surfaces that absorb heat but deflect water.

      Gloomy scales on a red maple branch. Photo: AG Dale.

      In previous papers, we have shown that the urban heat island effect can increase pest abundance on trees. Oak lecanium scales become more abundant due to greater survival on hot trees. Gloomy scales become more abundant because on warm trees more of them survive and they produce three times as many eggs.

      Adam measuring photosynthesis on a tree he has been watering with the green water bag around its trunk. Photo: AG Dale.

      In a new paper, Adam Dale (former PhD student now at University of Florida), shows that

      Gloomy scale embryos  that Adam counted to assess the effects of heat and drought on fecundity. Photo: AG Dale.

      drought, in addition to heat, is also an important mechanism by which gloomy scale abundance increases on urban red maples. This is among the best evidence that heat and drought – two major consequences of urbanization and of climate change – combine to benefit pests and thus must be studied in concert. Read more about it in Adam’s blog post.

       

      This article is published in the journal PLoS One. Find the entire article here: http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0173844

      Also, a UF press release can be found here: http://news.ifas.ufl.edu/2017/03/gloom-and-doom-when-these-insects-are-on-hot-dry-red-maple-trees/

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        March 10th, 2017|Categories: Uncategorized|Tags: |

        Would you give a few minutes a year to reveal the future of forests?

        What would be the easiest citizen science project ever? Watching paint dry? Falling off a log? Maybe. But what would you, or anyone else, learn from that?

        We are starting a citizen science project almost as easy but much more important. Its called A Tree’s Life and all you need to do is monitor red maple growth in your yard. We even give you the supplies. It’s really just one supply called a dendrometer, and it does most of the work.

        We want to measure trees because they have a very important job to do. Trees take carbon dioxide (a greenhouse gas) from the air and release oxygen. Even more important, though, is that they use the carbon to build more tree tissue. That’s how they grow, and as they grow, they store carbon that would otherwise remain in the atmosphere.

        Dendrometers are flexible plastic rulers that are installed on the tree’s trunk and expand as the tree grows. Photos: Michael Just

        Trees provide many other services like filtering air and water, providing shade to reduce energy costs, and generally make life better. Unfortunately, warming from urbanization and from climate change can reduce tree growth due to water stress, pests, and other factors. In other cases warming might make trees grow more and become healthier due to a longer growing season.

        The problem we want to address is that no one knows how trees in different habitats (urban, suburban, rural) and different latitudes will respond. So how can one predict the rate of carbon accumulation in the atmosphere, and thus climate change, if we don’t know how the primary terrestrial carbon sinks – trees – will respond? We can’t. Can we predict where urban trees and forests will thrive or decline? Not very well.

        Our goal is to monitor the growth, and thus carbon sequestration, of hundreds or thousands of trees to help figure this out. If you have a red maple and a few minutes each year, please help us. You will contribute to our (all of humanity’s) understanding of how climate change and urbanization will affect forest health and carbon sequestration by trees.

        Find out more about the study and sign up to participate.

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          March 7th, 2017|Categories: Feature, Urban Ecology|Tags: , , |

          Watch white peach scale – crawlers coming soon

          White peach scale (Pseudaulacaspis pentagona) is an armored scale common on many landscape plants and fruit trees. It has a wide host range including over a hundred plant genera such as Buddleia, Camellia, Clematis, Cornus, Euonymus, Hydrangea, Ilex, Ligustrum, Prunus, and many others. The most common host of samples submitted to the PDIC here at NCSU is cherry laurel (Prunus laurocerasus). Cherry laurel is an exotic species which of course is installed in nearly every new landscape I see.

          White peach scale females and males on cherry laurel. Photo: SDF

          Like most armored scales white peach scales are sexually dimorphic. The females are waxy bumps on twigs but the males grow wings and look like an actual insect. The males emerge from ‘pupal cases’ (not technically pupae). Twigs become covered with the fluffy white pupal cases. This is the easiest time to see and diagnose white peach scale infestations.

          Female white peach scale with cover removed surrounded by fluffy white male pupal cases. Photo: SDF

          Of course the males come out to mate. Two weeks after the males emerge females will begin producing eggs and crawlers will start hatching. Scouting for the males, even though they do not feed, gives you a head start to plan your management approach.

          White peach scales have 3 to 4 generations per year. Infestations are often concentrated on particular branches since scales do not move very far. Dense infestations can kill the individual twigs they are on. Minor infestations in landscapes should be monitored. You can probably inspect most cherry laurels and find some of these. That doesn’t mean you need to treat them; they can just hang out in low densities for years controlled by natural enemies. Plant stress and insecticide applications, like mosquito sprays, could increase the likelihood many armored scale species become problems.

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            March 7th, 2017|Categories: Landscape IPM|Tags: , |

            New Paper – Cities: more of the same for people and animals

            Say you are on a road trip. You fall asleep, head lodged against the (hopefully passenger side) window. The last thing you see before drifting off is a string of stores: Starbucks, Target, Bed Bath and Beyond, Walmart, Home Depot……Zzzzzzzzz.

            You wake up in half an hour, 2 hours, or 3 days, peek your eyes open and think you haven’t moved at all. The same string of stores would be outside your window again and again. Stop to eat in downtown Atlanta, San Antonio, Seattle or any city in between and you have the same experience. A few unique restaurants you never heard of and maybe you can track down some regional specialty but for the most part you have the same foods as in your home city.

            Look familiar? GoogleMaps.

            This is called ‘urban homogenization’ and animals experience the same problem. Herbivorous insects and pollinators find the same plant species in urban landscapes across the country. Look outside your window. Do you see holly, boxwood, azalea, ligustrum, and cherry laurel shrubs? How about the trees?: red maple, lacebark elm, crape myrtle, crab apple? Since the plant community looks similar so does the community of arthropods that use those plants for food. Bugs that need a ‘regional specialty’ may be excluded from urban ecosystems.

            The temperature, soil moisture, and air quality of distant cities are often more similar to each other than each city is to local natural areas. Kevin McCluney, a former postdoc in our lab (now at Bowling Green State University), conducted a study to determine if environmental homogenization among cities led to homogenization in arthropod hydration (or dehydration).

            Can you guess which is Orlando, Raleigh, and Phoenix? Photos: Kevin McCluney.

            Now, check out how different the natural environments are surrounding these three cities. They are in the same order as above: Raleigh, Phoenix, and Orlando. In the third photo, Kevin McCluney takes measurements outside of Orlando.

            In a new paper, Kevin and coauthors report that due to homogenization in plant communities and landscape maintenance practices, like irrigation, that arthropods in a wet city (Orlando) and temperate city (Raleigh) were less hydrated than in adjacent natural areas but arthropods from a dry city (Phoenix) were more hydrated than arthropods from the adjacent desert areas. Thus, arthropods in very different background climates become more physiologically similar in cities.

            Arthropod hydration and other physiological traits like heat tolerance affect their survival, plant and prey consumption, activity patterns, and reproduction. Understanding how physiological states change in cities can help predict the fate of species we are trying to conserve and the damage caused by pests to improve urban plant and wildlife management.

            Read the full article:

            McCluney,K.E., Burdine, J.D., Frank, S.D. (2017) Variation in arthropod hydration across US cities with distinct climate. Journal of Urban Ecology, 3 (1): jux003. doi: 10.1093/jue/jux003

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              March 3rd, 2017|Categories: Urban Ecology|Tags: , |

              Early spring flowers=Insecticide risk for bees

              Barberry is very attractive to bees and is blooming early in Raleigh. Photo: SDF

              Spring in Raleigh is almost a month ahead of usual (is usual a thing anymore?). This means we’ve had red maples flowering since mid-January. More importantly they have been visited by bees the whole time. Not just honeybees either. We have been trapping bees in red maples for the past month or so and found honeybees, bumblebees, and smaller Andrena spp.

              Today I noticed hollies flowering along with redbuds, barberry, and azaleas. Surely boxwoods, nandinas, cherry laurels, and other species attractive to bees are not far behind (or is it ahead?). This time of year folks making preventive insecticide applications may not usually think about bees and whether plants are flowering. Many insecticide labels restrict applications when bees or flowers are present.

              Hollies have small flowers that many people don’t notice but bees love them. Photo: SDF

              Neonicotinoids, like imidacloprid, have been in the news but label restrictions to protect bees are common on most insecticides including other landscape and nursery favorites like bifenthrin and orthene. To be safe: read the labels, don’t make applications when bees or flowers are present, and delay systemic insecticide applications until after flowering. A recent HRI publication and new bulletin and article from Michigan State University could help.

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                March 1st, 2017|Categories: Landscape IPM, Pollinators|Tags: |

                So you want to study bees? Check out BeeMORE – Paid Research Experience in Bees and Microbes

                If you are an undergraduate science major who is interested in pursuing a career in STEM, there is an exciting new opportunity to develop your skills while studying the interface between microbes and beesBeeMORE is a USDA-funded Research and Extension Experience for Undergraduates who are interested in significantly advancing their research skills in the field, the laboratory, or both.
                Potential projects include (but not limited to):
                – Disease ecology of native pollinators
                – Discovering new yeasts from beehives for brewing beer
                – Metagenomic surveys of bees and hives
                – Elucidating the gut microbiome of honey bee queens
                – Program runs from May 30th to August 3rd 2017 (9 weeks), and some accommodations for travel can be provided
                – Students will receive a $500 stipend per week ($4,500 total for the summer) PLUS free room and board at our Wolf Village Apartments
                – Successful applicants will be paired with faculty mentor programs to conduct their own research most amenable to their research interests and background
                – Activities will include presentations, group field trips, extension meetings, and the NC State Summer Undergraduate Research Symposium
                – DEADLINE: March 25th, 2017
                – Have more questions? Email us at: eric_miller@ncsu.edu or drtarpy@ncsu.edu
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                  February 28th, 2017|Categories: Pollinators|Tags: |

                  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: Pollinators|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: Nursery IPM|Tags: , |