Get to Know the Pollinators
Pollinators in Rhode Island
In Rhode Island there are a wide variety of pollinators that call our small state home. Pollinators come in all different shapes and sizes from beetles to birds and bats. These pollinators play a crucial role in Rhode Island’s agricultural success and the beauty of the state. A pollinator is an animal that transfers pollen grains from flower to flower. The pollen grains can then fertilizes the plant which leads to the growth of fruit, vegetables, and seeds.
Honey bees (Apis mellifera)
Honey bees are very social insects living in colonies that consist of three different castes of bees; the queen, drones and workers. The queen bee, the largest in the colony, is the only female that lays eggs She is the mother to the whole colony. The drones are males whose sole purpose is to mate with a queen. The workers are underdeveloped females that functionally run the colony. Worker bees range in jobs range from feeding the brood, caring for the queen, building beeswax comb, guarding and ventilating the hive, cleaning and repairing the comb, removing debris from the hive, and foraging for nectar, pollen and water. It is the worker bees in the hive that are responsible for the pollinating. On the workers’ hind legs are structures called pollen baskets that allow them to store the pollen grains. As the worker flies from flower to flower some pollen grains rub off onto the bee’s body hairs, head and mouthparts which can pollinate the flower. The remaining pollen is taken back to the colony where other workers make bee bread to feed the colony.
Honey bees are important because they have a very generalized diet and colonies are typically long-lived. Honey bees are commercially beneficial because the colony usually does not need to be replaced annually. They also have the ability to pollinate a large number of flowers due to their broad preferences for pollen and nectar. The worker bee that you would typically see flying around is up to sixth of an inch long, with a slender body shape, and has a hairy head and thorax (the body segment in the middle of the bee, where the wings are located). The honey bee head and thorax are black with light yellow hairs and the abdomen is yellow near the thorax with a black bands as it nears the back side of the bee.
Bumble bees (Bombus Sp.)
Bumble bees are unique pollinators in Rhode Island. Bumble bees are very similar to Honey Bees in colony structure, however, there are a few key differences such as the size of bumble bee colonies. Bumble bee colonies tend to be much smaller than Honey bee colonies, and unlike the Honey Bees they have seasonal colonies. Bumble bees are social and live in colonies but they aren’t as social as Honey Bees. They tend to have much smaller hives which gives them a lesser number of individuals to interact with. They have a very similar colony structure to honey bees as well. Their colonies consist of the queen, workers, and drones; and each caste plays the same roles as honey bees. There are however a few key differences in the queens of the two species. Bumble bee queens are the only bees from the colony to overwinter. The rest of the colony dies. She burrows into the ground to hibernates, in spring she emerges to find a place to start a new colony, preferably in a in a safe, dry area. Nests may be built in unoccupied rodent or bird nests.
The queen starts the colony and then as the workers start to hatch she focuses on reproducing while the workers run the colony. Bumble bees are generalist, meaning they are not particular when finding a food sources. Just like the Honey bees they also collect the pollen the same way, with pollen baskets on their hind legs. However, there is something special about the Bumble bees and how they pollinate flowers, they do what is called buzz pollination. Buzz pollination allows for the bumble bees to collect more pollen grains by vibrating their bodies. This action dislodges pollen grains and transfers them to the bee’s body making it easier for the flower to pollinate. You can identify most bumble bees by their large size--a little over an inch--and by their hairy bodies. Also, bumble bees usually have a black head and a yellow thorax (the body segment in the middle of the bee, where the wings are located). Their abdomen starts yellow near the thorax to about one segment down (the abdomen has 6 segments) where the coloration becomes black, however they can vary in color size and patterns.
Butterflies along with bees are also very important pollinators and they too are on the decline. Butterflies tend to be solitary, but there are a few exceptions such as the Monarch butterfly that winter in large groups in Mexico and California.
Although butterflies are important to pollination, they are less efficient at transferring pollen, than that their bee counterparts. With long, thin legs many butterfly species perch on the top of the flowers searching for their main source of food, nectar. This nectar is retrieved by a long proboscis that acts like a straw like tongue to sip the nectar, this method of retrieving food doesn't fully immerse the insect into the flower which results in less pollen grains being transferred. Butterflies favor brightly colored flowers with large landing platforms.
Butterflies go through four main stages throughout its life: an egg, caterpillar, pupa, and adult. The female butterfly usually lays her eggs on the underside of a leaf. She carefully selects a host plant for laying her eggs because this plant will be the first meal of the caterpillars that hatch from the eggs. But a host plant can be more than just a suitable food source, it also as acts as a microhabitat for half of a butterfly's life cycle. In the caterpillar stage the insect eats rapidly, shedding it’s skin up to 5 times before it is fully grown and becomes a pupa. A pupa is a stage where the caterpillar hangs upside down on a silk button, sheds its skin one last time and becomes encapsulated in its chrysalis. After development, an adult emerges from the chrysalis and begins its reproductive stage. This is the life stage where the pollination will occur. Butterflies tend to very brightly colored and they are only typically active during the day. They have long slender bodies and club shaped antenna.
Moths are very similar to butterflies, and are in the same family of insects, Lepidoptera. Moths though, have a few key differences. Moths tend to be active from dusk to dawn. This feeding schedule has a great impact on how the moths locate flowers and which flowers they prefer. Moths have a great sense of smell and can smell the nectar of a flower. This is important for nighttime feeding. If the scent of the nectar does not lead them to the flower then the color might. Moths tend to favor flowers that are pale in color, this color discrimination allows the moths to find the flowers that best reflect the moonlight.
Being nocturnal comes with another set of challenges, how to stay warm when the temperature drops at night. Moths have specific body characteristics that allow them to stay warm during the night time hours. They have developed a “shivering” method where they vibrate their flying muscles to create warmth. Along with “shivering”, moths also have hairy bodies which acts as an insulator to preserve body heat.
Some other body characteristic that set moths apart from butterflies is the shape of the body, antenna, wing posture and wing coloration. Moths are more stout in body shape than butterflies with feathered or pointed antenna. The different shape of the antenna depends on whether the moth is male or female. Males have feathered anneta to detect female pheromone and females have pointed antenna. When at rest butterflies and moths have different wing posture as well.
Moths tend to keep their wings folded in while butterflies tend to have their wings straight out and perpendicular to their bodies. The most striking difference between the two would be the coloration. Moths are often dull in color with varying browns and greys, while butterflies have vibrate colored wings. Moths are also slightly different in the pupa stage of life. Instead of hanging upside down and forming a chrysalis from a single point, moths create a cocoon from silk protein for extra protection. The cocoon can be attached in a multitude of different areas depending on the species.
Latest Pollinator News
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Audubon naturalists lead teams into the field to identify and record butterfly sightings. No experience is needed. This event is part of the North American Butterfly Association's annual survey of butterflies.
Come celebrate pollinators June 19th - 25th and help spread the word about how to protect them.
There is an increasing buzz about pollinators these days. But it’s not that sound in your garden as bees go about their business. Learn about what Audubon is doing to help our blossom-loving friends, what you can do at home and in your community and all about how you can celebrate National Pollinator Week with us!
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