Louise I. Lynch and Doug Golick, Department of Entomology, University of Nebraska-Lincoln.
Original article with photos at http://oxford.ly/2tsBiw1
An often-cited estimate is that one-third of the food you eat comes from insect pollinators. Many of the fruits and vegetables that you enjoy develop their fruit and seed primarily through insect pollination services. Other sometimes overlooked benefits of pollinators are the ecological services that they provide. For example, insects pollinate many plants that provide erosion control, keeping our waterways clean. Ground-nesting bees, meanwhile, can help aerate and mix soil. And yet another benefit is simply the aesthetic beauty that many pollinators have. Striking swallowtail butterflies, bustling orange-tailed bumble bees, rubicund milkweed beetles, and metallic green sweat bees beautify our landscape. Can you imagine a world without these creatures?
The critical role that pollinators play in our planet is the reason why both scientists and the public are so concerned about their declines. The US Fish and Wildlife Service’s recent designation of seven bees as endangered species has reinvigorated public attention to the plight of pollinators.
Pollinators face many known challenges. Pollinator health research has often focused on a select few pollinators, including the European honey bee, bumble bees, and butterflies (e.g. Monarch, Regal Fritillary). Less or no work has been done on most of the other 4,000 North American bees; the nearly 13,000 moths and butterflies; and many fly, wasp, and beetle pollinators. However, there are common threats that impact pollinator health and for which there is evidence in pollinator declines.
Habitat loss is one of the major culprits responsible for pollinator declines and impacts on their health. Lack of floral abundance, poor floral diversity, and forage habitat fragmentation are often cited as agents of declines in generalist pollinators. Specific larval plant hosts declines, like milkweed for monarch butterfly larvae, are also linked to pollinator declines. Also a loss or lack of nesting, overwintering habitat, and aggregation site disturbance can affect pollinator populations. Further, some pollinators like the Regal Fritillary require large stretches of very specific habitat types to complete their life cycle (e.g., tallgrass prairie and related open locations). For bees and adult moths and butterflies, one of the easiest things homeowners can do to help is plant a diversity of pollinator-friendly blooming plants in their landscapes.
Pesticide exposure, including insecticides, miticides, herbicides, and fungicides can harm or kill pollinators. Direct exposure to pesticides through spray contact have long been known to harm or kill pollinators. More recently, plant systemic pesticides, like those found in seed coatings, have been implicated in pollinator deaths or changes in pollinator behavior. Exposure to these pesticides can come through collection of seed coating fragments sloughed off during planting or through coming in contact with pollen and nectar containing traces of pesticides. Less understood is cross-pesticide target and class interactions and their impacts on pollinator health. A universally accepted approach to limiting the effects of pesticides on pollinators is to simply reduce or eliminate the use of pesticides in your landscape. In all cases, following good integrated pest management practices should be used to deal with any pest concerns.
Diseases and parasites are major factors in the health of pollinator declines. Perhaps most famous is the parasite Varroa destructor and its effect on European honey bees. Varroa mites parasitize developing and adult honey bees making them susceptible to diseases. If unmanaged, Varroa mites cause colony death. In other insect pollinators, like bumble bees, parasites and diseases are also a concern. Further, there is evidence in these bumble bees and other pollinators that disease and parasites are spread from managed bees to wild populations. While the magnitude of disease spread is not well understood, there are steps you can take to limit disease sharing. Hobbyist beekeepers should source honey bees from reputable breeders and watch for signs of disease in colonies throughout the year. If you think a disease is present, consult an extension expert for steps to manage diseases and parasites. Never release bumble bees and other lab-reared insects into the wild. Releasing these may expose wild populations to disease.
Other less-understood impacts on pollinator health include pesticide-class interactions, micro-habitat dynamics, invasive plant and animal species, and climate change. While less is understood concerning these impacts, much scientific investigation is currently being done to determine the nature and impact of these factors on pollinator health. With all of these issues facing pollinators, they need our help. Fortunately, there are many ways to get involved. Here are five ways you can help pollinators:
Plant for pollinators. One of the best ways to support pollinators is to feed them. Whether you choose to scatter seed or design a structured garden, thoughtfully include foraging habitat that provides nectar, pollen, and leaves. In temperate regions, homeowners should plant early and late blooming flower, shrubs, and plants, during times of the year when floral resources are sparse. Native and naturalized plants are fantastic, but non-natives can also provide good sources of pollen and nectar for generalist species. Nectar-sipping adult moths and butterflies start out as leaf-consuming caterpillars. Planting milkweed will support our declining Monarch butterfly populations. To start selecting plants for your area, check out the Xerces Society’s pollinator-friendly plant lists. For targeting specific pollinators or management of large areas of land, we recommend working with knowledgeable entomology or conservation professionals to plan and design these habitats.
Think outside the hive. “Home sweet home” for most bees is not in a hive. Most bee species are solitary, meaning each female bee makes a tiny nest by herself in soil or natural cavities. In fact, these bees are so docile and their nests so inconspicuous, you probably wouldn’t notice one right at your feet. You can provide natural habitat for solitary bees by leaving some bare soil on your property, and refraining from cutting back pithy-stemmed plants (some tiny bees build a small nest inside hollow stems). Take it a step further by building artificial bee houses from wood, natural stems, and other materials.
Become a citizen scientist. There is still a lot to be learned about pollinators. You can support timely, relevant, and impactful pollinator research programs by becoming a citizen scientist. Activities can range from monitoring habitats and submitting observations to sharing photographs or transcribing labels. Find a project that’s the perfect fit and pitch in.
Talk pollinators up. Learn about pollinators and share your knowledge with others. Many people only need a moment to realize how important pollinators are. By sharing your positive experiences with pollinators in the garden, on a walk or through citizen science, you can be an agent of change.
Celebrate Pollinator Week. Find a Pollinator Week event near you. Remember that Pollinator Week happens every year. Perhaps you will want to organize your own Pollinator Week Event.
Dr. Louise Lynch is a Postdoctoral Research Associate at the University of Nebraska-Lincoln. She is currently studying technology integration in undergraduate science courses. She has researched and worked with citizen scientists in several entomology programs to leverage their educational influence on others. She focuses on communicating scientific topics to a wide variety of audiences through various mediums, including citizen science, writing, science exhibits, workshops, photography and formal teaching.
Dr. Doug Golick is an Assistant Professor of Entomology at the University of Nebraska-Lincoln. He currently conducts research in the area of science literacy learning. His research, teaching, and extension programs reach a wide audience including children and adults in both informal and formal learning settings. Some of these programs include Bumble Boosters (pollinator education and citizen science programming), NSF funded faculty teaching development workshops, native pollinator habitat conservation research, and crop producer educational research.