DEEP: Pollinators in Connecticut

Pollinators in Connecticut
What are they? Why are they in decline? How can you help?
 
 
{honeybee} {metallic green bee} {spicebush swallowtail}
Honey bee
Metallic green bee
Spicebush swallowtail
 
Some plants require pollination to reproduce. This is the process by which pollen grains, produced in flowers’ stamens, are transmitted to a pistil where the pollen grains will then fertilize the flower. This leads to seed and fruit production.
 
As genetic diversity is important for healthy populations, flowers have evolved in several ways to ensure that pollen spreads between different plants of the same species. Pollen may be released into the wind and carried to other flowers, and some plants will even release pollen into flowing water. However, the vast majority of flowering plants make use of pollinators: animals that carry pollen from one flower to another.
 
Plants and pollinators have a mutualistic relationship – both benefit from the association. Pollinators may consume pollen and nectar provided by the plants and, in the process, additional pollen inadvertently will get caught on the hairs on the animal’s body. When the pollinator visits another flower, this pollen will be transferred, thereby fertilizing the second flower. More pollen is transferred to the pollinator, and the process continues. By offering rewards to these visitors, plants have shaped and continue to shape the evolution of their pollinators.
 
You may be familiar with the pollinating habits of bees and butterflies, but many other organisms may be pollinators. Certain flies visit flowers, as do some beetles, moths, and wasps. Hummingbirds are known to pollinate and, in some parts of the world, lizards, bats, and lemurs are also spreading pollen between flowers.
 
Bees: Bees are one of the most important groups of pollinators on the planet, and are responsible for the vast majority of insect-driven pollination. Bees are generally covered in fine hairs that can collect pollen, making them very effective at fertilizing the flowers they visit.

When thinking about bees, your first thoughts may be of honey bees. These industrious creatures are truly important in supplying us with fruits and vegetables (and honey too, of course). Honey bees can be domestic or wild. In North America, honey bees were actually brought to North America with the colonists. Honey bees, however, are not the only type of bees we have to thank for our food and flowers in Connecticut.
 
{bumble bee}
Bumble bees are important pollinators of wild flowering plants
and crops. Some plants, including tomatoes, peppers, and
cranberries, benefit specifically from bumble bee pollination.
{bumble bee}
Connecticut is home to over 300 different species of bees! Squash bees are important and efficient pollinators of squashes and related plants, such as cucumbers and pumpkins. Carpenter bees are a common sight in summer, appearing like giant bumble bees with shiny black abdomens. Mason bees, such as orchard mason bees, are important pollinators of many fruiting trees.
 
Bumble bees are another group of bees commonly seen. Capable of rapidly twitching their flight muscles, bumble bees engage in a behavior known as buzz pollination. The vibrations dislodge pollen from flowers that would not be released otherwise. Certain crops, such as tomatoes and eggplants, greatly benefit from buzz pollination to the point that bumble bees are also used as commercial pollinators. Bumble bee species are sometimes released into greenhouses to pollinate the crops within. This is how we get “hothouse tomatoes” in the cold weather months. In the wild, bumble bees form small colonies with a queen and just a few workers. These colonies are too small to yield honey like honey bee colonies. (A honey bee colony can consist of tens of thousands of individuals capable of producing an excess of honey that humans can harvest without compromising the bees' food supply.) Bumble bee colonies are usually located underground in an abandoned rodent tunnel or similar excavation.
 
While some bees are social beings, like honey bees and bumble bees, most of the 300 Connecticut bee species are solitary, meaning that they do not form colonies. Female solitary bees lay eggs in cavities in the ground or in wood, and line those cavities with leaves and mud. Mining bees, digger bees, oil-collecting bees are all solitary, ground nesting bees.
 
While it may be easy to notice honey bees and bumble bees in your garden, it is important to remember that they are not the only ones pollinating crops and flowers while we reap the benefits of their services.
 
Butterflies and Moths: Although butterflies and moths do not provide the same amount of pollination services as bees, they are certainly conspicuous creatures, garnering admiration and attention from scientists and citizens alike. Lepidopterans (the scientific name for butterflies and moths) do not consume pollen, but they will drink nectar using their long, tubular mouthpart (proboscis). Some plants have evolved specifically to be pollinated by these insects, hiding nectar deep in the flower such that it may only be reached with an extended proboscis. Generally, butterflies and moths do not carry as much pollen as bees because they are not covered in fine hairs. In addition, the long proboscis allows butterflies and moths to access a flower's nectar without becoming coated in pollen. Some pollen, however, may attach to the insects' feet and abdomen, facilitating pollen transfer between the flowers they visit.
 
{monarch butterfly} {snowberry clearwing moth} {skipper moth}
Monarch butterfly
Snowberry clearwing moth
Skipper
 
In a classic story of biological detective work, Charles Darwin once predicted the existence of a moth 40 years before its eventual discovery. He was shown an orchid from Madagascar with an exceptionally long, nectar-filled tubular structure (known as a spur) on the flower. He guessed that a moth must exist with a proboscis just long enough that the animal’s head would brush up against the flower’s stamens so that it would transfer pollen to the pistil of the next flower it drank from. In 1903, such a moth was documented in Madagascar, named Xanthopan morgani praedicta in honor of the prediction.
 
{hoverfly}  
 Hoverfly
Flies: Flies are important and often overlooked pollinators. While many plants offer bright colors and nectar to attract bee visitors, other plants may mimic carrion or dung with dark-colored flowers and strong, pungent odors to draw in flies, such as fungus gnats and carrion flies. Many hover flies (family Syrphidae) are bee mimics in both appearance and behavior. Though they share the same black and yellow coloration we associate with bees and wasps, they do not sting. In this way, animals that have learned to avoid being stung by bees and wasps will leave the stingless flies alone. This type of mimicry is known as Batesian mimicry – one harmless organism resembles a harmful organism to gain protection from predation. Pollinating flies are generally not covered in as much hair as bees, though they will still transfer pollen between plants from what sticks to their bodies as they forage.
 

{beetle}
 Pennsylvania leatherwing beetle
 
Beetles: Pollination by beetles accounts for a small percentage of overall flower pollination. Nevertheless, beetles, ranging from scarab and long-horned beetles to checkered beetles and tumbling flower beetles, may transfer pollen between flowers. Magnolias, for example, are visited by many insects during their flowering period; however, it is the beetles that are present when pollen is plentiful. In fact, the fossil record shows that magnolias evolved in a world without butterflies or bees. Therefore, this plant must have relied on other insects as pollinators. Given that beetles existed at the time magnolias arose and are still associated with the plant, it is reasonable to assume that beetles were some of their early pollinators.
 
Over the past decade, scientists have increasingly talked about pollinator declines – the noted decrease in these beneficial insects across the globe. Commercial honey bee hives have been experiencing significant losses in recent years, prompting investigation into its causes. Scientists and the public also have noticed that the once common rusty-patched bumblebee (Bombus affinis) has gone missing from the majority of its range in North America. Once commonly found across most of the eastern United States, it was only documented from Iowa, Illinois, Indiana, Wisconsin, and Maryland between 2001 and 2008. As for other pollinators, efforts are currently underway to search through existing specimens in museum and private collections to determine changing trends in pollinator abundance and diversity over time. Understanding population trends of the often overlooked wild bees is important given the pollination services they provide. The U.S. Department of Agriculture (USDA) states that 75 percent of the fruits and vegetables we consume require bee pollination.

In commercially raised bumble bees, several parasites have been identified as sources of mortality. These parasites have unfortunately escaped into wild bumble bee populations. Pesticide application and pesticide drift (the travel of chemicals from the intended area to non-target plants) also are believed to be killing bumble bees and other insect pollinators, including butterflies and moths. Habitat loss and fragmentation are hurting pollinator populations as more and more foraging areas and nesting habitats are destroyed. These vital members of our ecosystems are being threatened in many ways, and for most species, we do not yet know the extent of the damage.
 
In 2016, Public Act 16-17 was passed restricting the use of pesticides that cause serious harm to bees and other pollinators. It reduces the spraying of neonicotinoid pesticides, establishes a program to develop model pollinator habitat, and helps identify opportunities to conserve, protect, and enhance pollinator habitat.
 
 
Pollinators are in trouble, but you can help!
 
Local nectar and pollen sources are key to supporting local pollinators. To maximize the use of your yard, consider planting flowers that bloom from early spring through late autumn, thus providing a place where early-season up through the last-season pollinators can “fuel up.” Remove invasive plants, such as burning bush, autumn olive, Japanese barberry, and others, in favor of native plant species. For example, planting wild geranium and highbush blueberry for the early season; swamp milkweed and New Jersey tea for the middle of the season; and New England aster and wrinkleleaf goldenrod for the late season will provide blooming flowers from spring through fall. With the right mix of plants, you can turn your property into a haven for the entire year!
 
Pollinators need places to nest, feed, and protect their offspring. By managing your property to be pollinator-friendly, you may be able to greatly improve pollinator habitat. Maintaining natural areas (unmanicured areas of your property) is key for long-term pollinator protection. If you have a forest, meadow, or wetland on your property, bees will use those areas extensively for both feeding and nesting. You can also give wild bees a helping hand by providing nesting sites. These sites could be patches of untilled, bare, well-drained soil, which is perfect for many ground-nesting bees. Sites for wood-nesting bees include old logs with beetle burrows (for mason bees and leafcutter bees), or brush piles (for safe places to hibernate). To encourage butterflies, you should plant the caterpillar host plants. For example, monarchs need milkweeds to feed on as caterpillars. New Jersey tea is eaten by many Connecticut insects, making it a great addition to a pollinator garden. Planting native food plants in your yard or garden is a great way to encourage pollinators to flourish!
 
No matter the life stage, these insects are best protected by avoiding disturbances to their chosen wintering sites. It is important to support these organisms across their entire life cycle, including over winter. For example, mated queen bumble bees spend the winter under leaf litter or soil. Lepidopterans may overwinter as eggs, caterpillars, pupae, or adults. Plant management or soil disturbance is best conducted during late summer or fall to minimize negative effects to pollinators over wintering periods. If possible, management should occur in such a way that much of the habitat is left undisturbed in any given year, helping to protect species from the direct impacts of disturbance.
 
Above all, any space created for pollinators should be pesticide free. Insecticides are especially harmful to pollinators if applied at the wrong time or application rate. While it may not always be possible to completely eliminate pesticides from your garden or yard, you can certainly reduce the impacts on pollinators with a simple few steps. Chemicals should not be applied when pollinators are active – most pollinators will be resting during the night. Similarly, if possible, pesticides should be applied to the parts of the plant without flowers so that pollinators are not exposed to chemicals while visiting the flowers.
 
Pollinators and the White House:
 
You are not alone in your interest in pollinator protection! In June 2014, President Barack Obama released a memorandum outlining his commitment to “honey bees, native bees, birds, bats, and butterflies.” He has created a taskforce to develop and help implement recommendations for saving pollinator populations. President Obama highlighted the importance of these animals in our natural and agricultural systems, championing their cause from the highest office in the nation.
 
 
 
 
The Connecticut Agricultural Experiment Station – Protecting Bees from Pesticides. Includes recommendations on how to manage pesticide use in relation to bees.
 
State of Connecticut – Public Act 16-17 restricting the use of pesticides that cause serious harm to bees and other pollinators.
 
The Xerces Society for Invertebrate Conservation – See recommendations for native garden plants and nesting habitats.
 
National Geographic – Build Your Own Bee Hotel. Includes diagrams of three different hotel types, ranging in complexity.
 
The White House – Details regarding the White House’s strategy for pollinators.
 
The U.S. Fish & Wildlife Service – Includes many pages on pollinators and how you can help. A great resource!
 
PennState College of Agricultural Sciences – Center for Pollinator Research. Provides outreach information on providing food, shelter, and a safe environment for pollinators.
Providing Food for Pollinators
 
 
Content last updated on September 9, 2016.