20 Common Urban Pollinators
Did you know that San Diego County has the highest diversity of native bees anywhere in the continental United States? Scientists estimate that San Diego County is home to over 650 species of native bees! You may have heard of bumble bees, but they're just the beginning—digger bees, plasterer bees, sweat bees, leafcutter bees, cuckoo bees, and more, all call our county home.
Cute, fuzzy bees and lovely butterflies aren't the only pollinators, either. Flies, wasps, beetles, and more all play a part in providing pollination services, and their presence in a garden contributes to the richness of local biodiversity. The 20 pollinators listed below are some of the most common visitors we observed in our study. Explore in your own local garden or park and see if you can find some of these common urban pollinators!
Bombus sonorus (photo Ron Hemberger) |
Bumble bees (Bombus species) are a common visitor to tube-shaped flowers in gardens. They live in ground-nesting eusocial colonies similar to those of honey bees, but with fewer workers and much less honey. We have 7 species of bumble bee in San Diego County, one of which (Bombus crotchii) is listed as an endangered species. |
Halictus tripartitus (photo Seth Ausubel) |
Furrow bees (Halictus species) are a ubiquitous visitor in San Diego gardens. They are dietary generalists, which means they can feed on nectar and pollen from a wide variety of flowers, and can often be found flying throughout the year in mild climates. Many species are eusocial and live in small colonies, which can range in size from 4 to 200 individuals. |
Lasioglossum (photo Tim Turner) |
Sweat bees (Lasioglossum species) are closely related to furrow bees, and similarly found on a huge variety of flowers. Different species vary tremendously in their appearances and life histories: some are nocturnal, some steal the pollen sources of other bees, and many are dietary specialists! |
Agapostemon texanus (photo Molly Jacobson) |
Striped and green-sweat bees (Augochlorella species and Agapostemon species) are in the same family as furrow and sweat bees. They're remarkable for their bright metallic green exoskeletons, unlike any other bee in our area! Watch daisies and tickseed to see them collect pollen. |
Anthophora urbana (photo Carol Davis) |
Digger bees (Anthophora species) are round, robust bees that are often found on sages and other plants with floral spikes. Much faster fliers than bumble bees, they’re hard to spot, but when they land, notice the color of their compound eyes, which are frequently blue or green. |
Syritta (photo Kevin Hall) |
Hover flies (family Syrphidae) are frequent flower visitors and pollinators, and their larvae are highly beneficial predators of insect pests. Studies have been done to test their potential as a combination pollinator-pest control. |
Systoechus (photo Fitz O. Clarke, Jr.) |
Bee flies (family Bombyliidae) mimic the furry hairs of bees as a defensive measure against predation. They can be distinguished from bees by their wings held outstretched, compared to bees’ folded wings. Their larvae parasitize beetle and wasp larvae underground. |
Hippodamia convergens (photo Gary McDonald) |
Lady beetles (family Coccinellidae), famous for their use as biological control of aphids, mealybugs, and other pest insects, often visit flowers to feed on nectar. While familiar species are red with black spots, they come in a variety of colors, including orange, black with red spots, and black with white spots! |
Listrini (photo Robert A. Behrstock) |
Soft-winged flower beetles (family Melyridae, subfamily Dasytinae) are pollen feeders that also prey on flower-visiting insects, and are likely contributors to pollination services. |
Mordellistena (photo Kurt Hennige) |
Tumbling flower beetles (family Mordellidae) are frequently found in flowers, where they eat pollen. Their wedge-shaped bodies and pointed abdomens are unmistakable. |
Melissodes (photo Seth Ausubel) |
Long-horned bees (Melissodes species) are a common mid-sized bee that flies in the summer and early fall. Some are dietary specialists, but almost all prefer flowers in the sunflower family (Asteraceae). The genus is named after the males, whose antennae can be as long as their bodies! (Females have standard-sized antennae.) |
Calliopsis rhodophila (photo Hartmut Wisch) |
Mining bees (family Andrenidae) are a widespread family, with over 1,200 species found in North America. They tend to be more slender than either leafcutter bees or digger bees, with smallish heads. Some are hyper-specialists, visiting just one or two species for their pollen needs. One common genus is Calliopsis, frequently found foraging close to the ground near hardpacked open soil in urban landscapes. |
Oxybelus (photo Daniel K. Horner) |
Crabronid wasps (family Crabronidae) are the closest evolutionary link to bees, and many rely solely on pollen and nectar as adults. They are almost indistinguishable from bees at a glance, but look for short, silvery hairs that reflect light. Bees have fluffy, branched hairs to maximize the amount of pollen they can collect. |
Polistes dorsalis (photo Aaron Schusteff) |
Vespid wasps (family Vespidae) frequently visit flowers for their nectar resources. Wasp larvae, on the other hand, are carnivorous, and eat caterpillars and other animal protein sources that the adults have collected and brought back to their mud or paper nests. |
Phoebis sennae (photo Bob Peterson) |
Cloudless sulphurs (Phoebis sennae) range from southern Canada to Argentina, feeding on nectar from a wide variety of different flowers. They reproduce at a rate of two generations per year. This highlighter-yellow butterfly is commonly found in open spaces and gardens in the coastal and foothill regions. |
Pieris rapae (photo Zeynel Cebeci) |
Cabbage whites (Pieris rapae) are ubiquitous in flowery urban spaces. Native to the eastern Mediterranean, they have been accidentally introduced throughout the world, where their larvae plague crops such as cabbage, bok choy, broccoli, and other cruciferous vegetables. |
Hylephila phyleus (photo Bob Peterson) |
Fiery skippers (Hylephila phyleus), sometimes called “California’s most urban butterfly,” can be found as far south as Chile. They “skip” rapidly from flower to flower and can be found as late in the year as October. Fiery skippers are members of the skipper family (Hesperiidae), a family formerly not thought to be “true” butterflies, but recent DNA work places them along with other butterflies. |
Polites sabuleti (photo Brad Smith) |
Sandhill skippers (Polites sabuleti) are another skipper common in urban gardens. Coloration is highly variable. Caterpillars are hosted on various species of grass, including common lawn grasses. |
Leptotes marina (photo Aaron Schusteff) |
Marine blues (Leptotes marina) have a wingspan of just 0.8-1.1 inches, categorizing them among our smaller butterflies. Two eyespots with iridescent coloration distinguish the undersides of their hindwings. They have a fondness for flowers in the mint family (Lamiaceae). |
Erynnis funeralis (photo Mathew L. Brust) |
Funereal duskywings (Erynnis funeralis) are another species of skipper, whose larvae are usually found on plants in the oak, legume, and buckthorn families. Distinguishing one species of duskywing from another is very difficult without a microscope. |