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As you may have heard, this week is officially Pollinator Week!  It’s not that the pollinators are aware of that, but as gardeners, it is an excuse to stop and think about the pollinators in our gardens, and consider how diverse pollinator species can be.

Over the last 48 hours I’ve been trying to pay closer attention to who is visiting which blooms in our gardens.  Even though I can’t, at least not yet, identify all the different species I encountered, I can still be impressed at the diversity of species that are frequenting our flowers.

When we think of pollinators, it’s easy to automatically think of honey bees.  We do keep honey bees, and although they are the obvious pollinators here, they aren’t working the gardens alone.  We’re also doing what we can to encourage native bees, and other pollinator species, to visit the gardens as well.

Our honey bees aren’t the only pollinator species on the farm

There’s some debate as to whether or not the presence of honey bees may negatively impact the ability of native pollinators to gather nectar and pollen from the same resources in a particular area.  Scientists may never be able to answer that question, as honey bees are now ubiquitous throughout North America.  What is apparent though, just from casual observation, is that different bee species show preferences for different species of flowers, and this highlights the importance of plant diversity in the garden.

We have some sizable Scrophularia californica on the property this spring, and the honey bees are very obviously drawn to its nectar.

The honey bees are mobbing the tiny Scrophularia blooms for their nectar

Honey bees are so large compared to some of the native bees, that the native bees, like this Ceratina sp., can be easily overlooked!

A small Ceratina sp. bee on Scropularia californica

Where the honey bees at the moment are mobbing the Scrophularia, creeping thyme, and the lavender flowers, the native bees seem rather enchanted with the native Salvia and Eriophyllum blooms.

I spent quite some time lurking among the Eriophyllums, because these particular flowers seemed to attract a wide diversity of insect species compared to almost anything else in bloom here this week.

The broad flowers of Eriophyllum lanatum ‘Siskiyou’ are appealing to a wide variety of pollinator species

Different bees have different preferences for flowers, perhaps due to color or shape, but not all flowers are accessible to all bee species.  This in part is due to variation in tongue length between species.  Short-tongued bees can easily reach the nectar and pollen in an open flower like Eriophyllum, but may find it more difficult to access stores in long, tubular-shaped, blooms.

Tubular flowers, like these Salvia blooms, don’t give up their nectar and pollen quite so easily

Some species of bees may show a preference for foraging on a single flower species.  These specialist bees are said to be monolectic foragers.  More commonly bees may show a preference for a particular genus, or family of flowers, and these are termed oligolectic bees.  For example, some of the so-called ‘sunflower bee’ species will preferentially forage on flowers in the Asteraceae family.  Polylectic bee species are considered generalists though, and will forage on a wide variety of flower types. [1] The more specialized a bee’s foraging strategy is, the more sensitive they are to changes in their environment, and habitat loss. [2]

Sunflower bees are named for their preference for foraging on flowers in the Asteraceae family, like this Encelia

This preference for a species or family of blooms is why it’s important, when planting with pollinators in mind, to plant in large drifts of the same species/family of blooms.

Encelia, and Eriophyllum, are both in the Asteraceae family

Even if our preference is to mix up the annual or perennial borders for our own visual interest, foraging for pollinators is vastly more efficient if the same flower varieties, or families, are kept close together.

Grouping flowering plants in drifts, like this thyme, makes it easier for pollinators to find their preferred food

Bees aren’t the only winged pollinators in the gardens though.

Fly feeding on Eriophyllum confertiflorum nectar

Flies, believe it or not, can be pollinators too, especially hairy species who inadvertently drag pollen around on their bodies.  I’m not encouraging the proliferation of flies in the garden, but they do play their part in pollination too, even if it’s accidental.

Flies stealing nectar from flowers may accidentally transfer pollen between plants

Syrphid flies, bee flies, and other bee-like mimics can be observed visiting the flowers in the garden too.

This fly species resembles a bee

The bee-flies (Bombyliidae sp.) don’t seem particularly fussy where they feed in the garden.  Although I frequently found them foraging among the native sage blooms, they’re just as happy feasting on Lavender or Verbena.

Bee-Flies are easily recognized by their long proboscis

Nearby, despite the disguise, the eyes, antennae length, and wing shape, show this bee-mimic is also actually a fly, and seems to enjoy lurking among the native poppies.

This bee-like fly is foraging on native California poppies

Even this mosquito-like insect is drawn to some of the flowers.

Is there anything that’s not attracted to Eriophyllum?

I’m not sure what species this is, but its golden coloration is quite stunning for such a small mosquito-like insect

Back to the bees though, the native sages are clearly enticing a number of bumble bee species.  This spring we’ve observed lots of what appears to possibly be Bombus flavifrons [3] this year.

These yellow bumble bees, possibly Bombus flavifrons, are frequently found among the sage blooms

I don’t recall seeing this species in previous years here.  These hirsute, vividly colored, bumble bees are difficult to miss, and sometimes more than a dozen were found working the same plant.

Salvia ‘Pozo Blue’ appears to be a particular favorite for this species of bee

They really seem to favor the native sages, and thus far are completely ignoring the Lotus scoparius flowers, which are clearly more attractive to other bumble bee species.

The Yellow-Faced bumble bees (Bombus vosnesenskii), and Bombus bifarius, can be found working the deerweed (Lotus scoparius) flowers throughout the day.

Yellow-faced Bumble Bee (Bombus vosnesenskii)

This species, possibly Bombus bifarius, prefers the Lotus scoparius blooms

The Eriophyllums we planted this Spring though, are also proving to be a big hit with the sweat bees, including this metallic green Agapostemon texanus.

The sweat bees, including Agapostemon sp., are also attracted to the Eriophyllum flowers

I’d personally like to rename sweat bees, who never seem that attracted to me, no matter how much I’ve overexerted myself in the garden, to ‘zippy-I-won’t-bee-caught-on-camera bees‘.

The sweat bees also were found on the Encelia

They are almost impossible to capture with a camera, as they barely sit still long enough for the shutter to release.

Keeping up with these bright flashes of green among the flowers can be challenging!

Maybe for simplicity sake I’ll just call them ‘I-won’t-sit-still-bees’!

Sweat bees were also found rolling around among the poppies, gathering pollen.  Although, honestly, I couldn’t quite determine which species of sweat bee these are.

These bees were busily working the poppies for their pollen

Regardless, the poppies were very popular with this species of bee.

Quite a few of the poppy flowers were occupied!

It’s not just bees though. Hoards of syrphid flies are also found among the flowers.  They seem to especially favor the Hyssop in the herb garden at the moment, and the Eriophyllums in the native gardens too.

A pair of Syrphid Flies on Eriophyllum

In fact, if I was to pick a peak pollinator attractor at the moment, in our gardens, that isn’t lavender, or thyme…Eriophyllum is clearly the place to be seen.

Syrphid fly adults are pollinators, but their larvae are reknowned for eating aphids!

Everything loves these gloriously sunny, and radiant flowers.

Also in the Syrphidae family are the Sphegina flies, here perched on hedge parsley (Torilis arvensis)

The Eriophyllum flowers are also very attractive to butterflies.  This time of year the predominant species seem to be the Skippers, including this Mournful Duskywing.

Mournful Duskywing (Erynnis tristis)

There were also quite a few Rural Skippers (Ochlodes agricola), but they succeeded in evading my lens, unlike the Woodland Skippers (Ochlodes sylvanoides) that didn’t seem to mind the camera as much.

A Skipper feating on sage nectar

Checkerspots (Euphydryas chalcedona) are prevalent in the gardens too.

Variable Checkerspot (Euphydryas chalcedona)

Sharing the same flowers, an American Lady butterfly (Vanessa virginiensis).

American Lady Butterfly (Vanessa virginiensis)

American Lady Butterfly (Vanessa virginiensis)

Unfortunately, where the pollinators thrive, the predators also lurk.  Pollination, in our gardens at least, is risky business.

Crab spiders can change colors to better blend in with the flowers where they lurk waiting to catch prey

This Syrphid fly, enticed by the promise of nectar and pollen, met a premature end when this camouflaged crab spider snagged it for a meal.

This crab spider has caught a syrphid fly. It’s a tough world out there for pollinators

I’m actually quite surprised at both the prevalence, and the variation in coloration of our crab spiders this season.

Our native poppies seem especially popular with the crab spiders this season

The next poor unsuspecting pollinator to approach this flower is in for a surprise!

This crab spider is hoping it won’t be seen by the next pollinator to visit this Rudbeckia bloom

In the orchard, another one of our honey bees didn’t see what else was lurking among the poppies until it was too late.

This ambitious crab spider chose a honey bee for its next meal

How on earth does a spider, no larger than honey bee itself, secure this for dinner?

Of course, thus far, I’ve focused on bees, and bee-like flies as the principle pollinators in our gardens. They are important pollinator species here, but others are also doing their part in the gardens too.  Beetles, in fact, are important pollinators too, especially for older species of flowers.

Beetles are often overlooked as pollinators

Remember, honey bees are a relatively recent introduction to the Americas, and a number of blooms relied on beetle pollination before the arrival of the European honey bee.

Beetle species are numerous, and we have a number of different species here on the farm.  Each spring, hoards of Soldier beetles can be found clustering around plants that are infested with aphids.

Beetles, like this Soldier Beetle, can also transfer pollen between flowers, while hunting aphids

Aphid-hunting Lady Beetles, albeit inadvertently, can also move pollen from plant-to-plant.

Lady Bugs aren’t a major pollinator species, but they still count

These small black beetles appear predictably each year on the Encelia flowers.

Something about Encelia is very attractive to this species of beetle

Beyond the bees and beetles, we’re also finding lots of Katydids among the flowers.

Katydid on native Salvia

Quite a few Katydid nymphs too, especially on the native poppies.

These Katydid nymphs were found on this poppy flower in the morning

By the afternoon though, this flower was looking somewhat worse for the wear

Like the Katydids, grasshoppers aren’t principle pollinators, but they may still inadvertently transfer pollen between flowers.

Grasshopper on hyssop in the herb garden

Birds can also be considered to be pollinators, especially the nectar feeders, like hummingbirds.  This particular bird was taking a break to bathe in our recently installed rock fountain. So far we’ve watched both Anna’s and Allen’s hummingbirds enjoying a brief splash in the water as it flows over the rock.

As hummingbirds feed on nectar, they can also transfer pollen between the flowers

What we don’t see are the night pollinators though.  I keep thinking it would be fun, to camp out with camera at the ready, to see if I can spy any sphinx moths, or bats, on pollination patrol.

Pollinators also include creatures active at night, including moths like this Pale Beauty Moth (Campaea perlata)

Honey bees are important for crop pollination, but as their populations have declined due to mite, and disease issues in recent years, the wide variety of native pollinator species here are just as important, if not more so.

If you’re curious to see how many pollinator species are in your garden, find an accessible species of flower blooming in your garden, a broad, open, flat flower species that appeals to a diverse array of pollinator species.  Then stand still, for at least 20 minutes, and see just how many different species you can observe.

Thanks to the hard working pollinators in our garden, we’ll soon have some cucumbers to look forward to

The diversity of pollinators hard at work in your garden might surprise you!

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[1] Eric Mader, Matthew Shepherd, Mace Vaughn, Scott Hoffman Black.  2011.  Attracting Native Pollinators: The Xerces Society Guide Protecting North America’s Bees and Butterflies.

[2] Matthew Shepherd, Stephen L. Buchmann, Mace Vaughan, Scott Hoffman Black  2003.  Pollinator Conservation Handbook: A Guide to Understanding, Protecting, and Providing Habitat for Native Pollinator Insects.

[3] Jonathan Koch, James Strange, and Paul Williams.  Bumble Bees of the Western United States.  U.S. Forest Service, and the Pollinator Partnership.