The week of June 17-23 is National Pollinator Week, which celebrates the vital winged creatures we are so dependent on to pollinate most of the flowering plants in the world. Pollination is the process of transferring pollen from the anthers (male part of flower) to the stigma (female portion of flower), thus allowing fertilization to occur. Three-quarters of flowering plants and over one-third of the world's crop species depend on pollination for reproduction. Crops dependent on pollination include apples, berries, peaches, eggplant, coconut, cocoa, coffee, nuts, avocado, oil crops (i.e. sunflowers, sesame), soybeans, and melons.

Pollinators receive food in the form of nectar (source of sugar) or pollen (source of protein, fat, and other nutrients). In the process of moving from flower to flower to feed, pollinators disperse pollen grains among plants of the same species, enabling the plants to reproduce. Flowers have evolved over long periods of time into many colors, shapes and scents to attract their pollinators, thus creating a mutually beneficial relationship.

The Pollinators

While bees are the primary pollinators, other insects including butterflies, moths, flies, beetles, wasps, some birds such as hummingbirds, and bats also play important roles.

Honeybees & Native Bees

Honeybees (genus Apis) are the bees we are most familiar with. However, honeybees are just one species of a very diverse group with over 20,000 species worldwide, 4,000 species in the USA and 1,600 in California. Native bees come in a variety of shapes, colors, sizes and lifestyles that make them very efficient pollinators. Unlike honeybees and bumblebees, which are social bees living in colonies, native bees are solitary with 70 percent nesting in the ground with the rest nesting in wood and plant stems.

Butterflies

Butterflies are daytime flying insects who often have gorgeous colorful wings. Their larvae sometimes require a specific plant to feed on, though most adults will get their nectar from many plants.

Moths

Moths are mostly evening and nighttime fliers, though some are out in the late afternoon or early morning. They are attracted to sweet-smelling flowers. Less colorful than butterflies, they are easily differentiated from butterflies by their “feathery” antennae.

Flies

Flies are not generally thought of as pollinators, however many are, particularly hover flies (family Syrphidae) and bee flies (family Bombyliidae), both of which are generalist pollinators. Generalist pollinators visit a wide range of plants, making them important inhabitants of gardens and fields.

Beetles

Beetles are a large group, with up to 28,000 species in the USA. Most beetles are not pollinators, but some do visit flowers for nectar or pollen and help fertilize some flowering plants, particularly magnolias.

Wasps

Wasps, like beetles, are less efficient pollinators, but they can still have an impact on the ecosystem.

Hummingbirds

Hummingbirds are the most prominent pollinating birds in the Americas. With their long beaks, they can reach deep into flowers while sipping nectar. In addition to nectar, they also forage on insects and spiders.

Bats

Bats are nocturnal pollinators that play an important role in pollinating cacti and agave, as well as many tropical and subtropical plants including bananas, avocados, century plants and cashews. Species such as Mexican long-nose bat (Leptonycteris nivalis) have evolved heads and long tongues to access light-colored flowers which open at night, often producing abundant nectar and pollen.

How You Can Help Pollinators

Due to climate change, the reduction of native habitats, and environmental chemicals, many pollinators are struggling.

Pollinators need a diversity of flowers with lots of nectar and pollen. They require easy access to flowers blooming throughout the seasons, particularly during late winter, early spring, and late autumn seasons when fewer flowers bloom. Different flower species provide differing amounts of nectar. Native plants generally provide more nutritious nectar for pollinators, so they attract more pollinators. Download the Xerces Society Recommended Plants for the Central Valley Region for a list of plants.

To help protect pollinators, if you choose to use a pesticide, select one that are less toxic, such as an insecticidal soap or oil. Avoid broad-spectrum sprays that kill numerous insects. Spray on non-windy days in the early morning or late evening when pollinators are not present. Use UC Integrated Pest Management for information on pests and pest management (https://ipm.ucanr.edu/).

Pollinators are wings of life since we would be deprived of many fruits and vegetables we enjoy, and our world would be drearier without the colorful flowers they fertilize. Help celebrate and support these vital winged creatures by providing flowering plants in our gardens to help pollinators thrive, which will also produce lovely, varied landscapes for us to take delight in.

Citations

• The Pollinator Partnership https://www.pollinator.org/
• Xerces Society book: Attracting Native Pollinators: https://xerces.org/publications/books/attracting-native-pollinators
• California Native Plant Society (CNPS) native planting guides: https://www.cnps.org/gardening/choosing-your-plants/native-planting-guides

Free Resources from University of California and your local UC Master Gardeners

• CA Friendly Friendly Garden Recipes https://anrcatalog.ucanr.edu/Details.aspx?itemNo=8518
• How to Attract and Maintain Pollinators in your Garden https://anrcatalog.ucanr.edu/Details.aspx?itemNo=8498
• UC Stanislaus County Master Gardener: Butterflies in Your Garden with list of plants that attract butterflies: https://ucanr.edu/sites/CEStanislausCo/files/345791.pdf
• Gardening for Pollinators and Diversity from UC Davis Arboretum: https://arboretum.ucdavis.edu/pollinator-gardening
• Bees in the Neighborhood: best practices for urban gardeners. https://anrcatalog.ucanr.edu/Details.aspx?itemNo=8596

Books and ID Cards for Purchase

Common Bees in California Gardens https://anrcatalog.ucanr.edu/Details.aspx?itemNo=3552-2
Common Plants to Attract California Native Bees https://anrcatalog.ucanr.edu/Details.aspx?itemNo=3557
Want both cards? Bundle and save $10 at https://anrcatalog.ucanr.edu/Details.aspx?itemNo=3557BUN

Denise Godbout-Avant has been a UC Cooperative Extension Master Garden in Stanislaus County since 2020.