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.

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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: , , , , |

            National Ornamental Workshop: Register Now

            For 40 years people have met in the mountains of North Carolina to talk about pests and pathogens of ornamental plants. It started as a few professors chatting about new pests problems by day and playing music by night. It has grown considerably; the last Ornamental Workshop in 2014 attracted 130 people from 35 states. Attendees included academics, extension personnel, members of the agrochemical and biocontrol industries, non-profit organizations, and others.

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            This year the Ornamental Workshop is October 24-27. Although the meeting has grown it is still fun and informal. We mix presentations and discussions. Sometimes entomologists and plant pathologists meet separately to focus on the intricacies of each discipline. We also come together for sessions important to both like arthropod transmitted plant pathogens and extension innovation. What’s more it’s held at a secluded mountain retreat with nightly socials to encourage (force?) networking and hopefully making new friends.

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            The Ornamental Workshop is a place for people to share new research, extension, and pest management practices with other research and extension professionals. There is no trade show, no pesticide credits, and no formal training. But, if you have ideas and information to share this is the place to do it. Register and submit your presentations here. Contact Steve Frank (sdfrank@ncsu.edu) with questions.

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              September 1st, 2016|Categories: Lab Happenings|Tags: , |

              Bees and army bands: The remarkable life of TB Mitchell

              This is a guest post from our Research Associate, Elsa Youngsteadt

              T. Mitchell

              A portrait of T.B. Mitchell in the lab. Image courtesy of Special Collections Research Center, North Carolina State University Libraries; photographer unknown.

              T.B. Mitchell is probably the reason we ecologists in eastern North America can identify our bees. Mitchell joined the faculty here at NC State in 1925 and distinguished himself as a meticulous taxonomist.

              Although he died in 1983, more than 30,000 of his bee specimens are housed here in the NC State Insect Museum, where one can occasionally feel a little time warp: The specimen I am examining right now, under the microscope, was alive in 1925. It was cruising from flower to flower along some North Carolina country roadside 91 years ago when Mitchell nabbed it with his net. He pinned it, identified it, labeled it, may have studied it while writing the key I’m now using—and I’m handling that exact bee, comparing it to one of the same species that I caught last week.

              Enough of this kind of thing, and you wish you could meet the guy who made the collection. Thanks to lab alum April Hamblin’s idea to propose a Heritage column for American Entomologist, we nearly feel that we have. April, Margarita López-Uribe, Heather Moylett, and I spent the better part of a year, off and on, going through boxes of letters and stacks of theses, reading Mitchell’s papers, and conducting interviews and correspondence—including actual paper letters. The resulting article is published in the fall 2016 American Entomologist. We invite you to read it and get acquainted with this energetic, unflappable gentleman, his scientific contributions, and his remarkable experiences as a musician and entomologist.

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                August 30th, 2016|Categories: Lab Happenings, Natural History and Scientific Adventures, Pollinators|Tags: |

                New paper: Media moisture thresholds for ambrosia beetle IPM

                Ambrosia beetles are among the most damaging pests of nursery. The main culprits are granulate ambrosia beetle (Xylosandrus crassiusculus) and the black stem borer (X. germanus). We have worked on ambrosia beetles for several years to find ways to reduce damage and insecticide use. Recently though, in collaboration with Chris Ranger at USDA ARS in Wooster and other scientists, we finally got to the root of the problem: why do ambrosia beetles attack nursery stock to begin with?

                Chris and other collaborators started down this road with the realization that when trees get too much water they release ethanol through their bark. And what is the lure in ambrosia beetle traps?: ethanol.

                Flooded trees produce ethanol which is the lure as in ambrosia beetle traps use ethanol

                Flooded trees produce ethanol which is the lure in ambrosia beetle traps use ethanol. Photo: SD Frank

                The question then became “how wet is too wet?” If nurseries could prevent trees from getting ‘too wet’ water maybe they could stop ambrosia beetle attacks all together. To answer this question we grew Florida dogwoods in containers and maintained 10, 30, 50, 70, or 90% media moisture throughout the spring. It turns out that trees above 50% media moisture got hammered by ambrosia beetles and those below did not get attacked at all. So, at least for dogwoods, we recommend a media moisture threshold of 50% or below to reduce ambrosia beetle attacks.

                Experimental trees with covers to help regulate media moisture. Photo: SD Frank

                Experimental trees with covers to help regulate media moisture. Photo: SD Frank

                Next we measured media moisture at 6 cooperating nurseries each spring for two years. Unfortunately, containers at most nurseries were above the 50% threshold during peak ambrosia beetle activity in early spring. Thus, trees in these nurseries smelled sick to ambrosia beetles and were susceptible to attack.

                Reducing media moisture in spring is a challenge because the weather is cool and often wet and trees are not transpiring. That said, sometimes we found irrigation systems were operating during ambrosia beetle season when they probably weren’t required. More research is required to develop horticultural tactics, such as new substrates, to reduce spring media moisture. In the mean time though growers can add the media moisture threshold of 50% to their IPM toolbox to use in combination with other tactics like trapping and insecticide applications.

                Frank, S. D., and C. M. Ranger. 2016. Developing a media moisture threshold for nurseries to reduce tree stress and ambrosia beetle attacks. Environmental Entomology 45: 1040-1048.

                 

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                  August 23rd, 2016|Categories: Nursery IPM|Tags: , |

                  Crape myrtle bark scale: New tree pest has arrived in NC

                  A couple years ago I began warning about a new pest that was spreading throughout crape myrtle country. Now, the crape myrtle bark scale has arrived. From the severity of the infestation it looks like it actually arrived many years ago but now it is “official.” This is bad news because crape myrtles are one of our most commonly planted trees in yards and along streets. Crape myrtles are typically almost maintenance free (unless you top them) but now they will require pest management to stay healthy and beautiful.

                  Crape myrtle bark scale. SD Frank

                  Crape myrtle bark scale. SD Frank

                  Female scales produce fluffy white filaments that cover their body. In spring they produce eggs beneath their body then die. Tiny crawlers hatch from the eggs, settle in their new spot, and begin producing white filaments. They have at least 2 overlapping generations. At low density, crape myrtle bark scale feeds in rough areas around branch collars but as the population increases all the bark may be covered. These scales are most often noticed because trees become covered in black sooty mold. At first many people assume this is from crape myrtle aphids so the scales may go undetected. If you notice unusually heavy honeydew and sooty mold on crape myrtles take a closer look at the bark.

                  Crape myrtle bark scale is a felt scale related to azalea bark scale and oak eriococcin scale. They feed on phloem like other “soft scales”, thus the honeydew. Even though there is not a lot of efficacy data available drench applications of neonicotinoids are typically effective against phloem feeders. However, since crape myrtles flower continually and attract a slew of pollinators be sure to read the labels for restrictions on using them. Insect growth regulators such as pyriproxyfen and buprofezin are effective for many other scales and may be a good option. Horticultural oil, especially the heavier dormant rate, can reduce scale abundance also.

                  Crape myrtle bark scale on a rough branch collar. SD Frank

                  Crape myrtle bark scale on a rough branch collar. SD Frank

                  There are many subdivisions and streets in North Carolina lined with crape myrtles. Inspect these trees to determine when they become infested. Also consider diversifying the tree planting of your neighborhood. Luckily this pest does not kill trees outright like some other exotic pests increasing tree diversity helps ensure all the trees are not infested or killed at once by a single pest.

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                    August 8th, 2016|Categories: Landscape IPM|Tags: , |

                    Emerald ash borer cropping up in new NC counties

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                    Silhouette of an ash tree infested with EAB showing classic thinning in the crown. Photo: David Cappaert, Bugwood.org

                    Emerald ash borer is continuing to spread through NC. So far this summer, it’s already been found in four new NC counties (Davidson, Forsyth, Swain, and Yancey). At this rate, the NC Forest Service is anticipating a lot more findings and is asking folks to keep their eyes peeled for tell-tale signs of beetle activity.

                    Check out this month’s Forest Health Note for more info on EAB in NC.

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                      July 21st, 2016|Categories: Urban Ecology|Tags: , , |