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.
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.
Honey bees are so large compared to some of the native bees, that the native bees, like this Ceratina sp., can be easily overlooked!
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.
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.
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.  The more specialized a bee’s foraging strategy is, the more sensitive they are to changes in their environment, and habitat loss. 
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.
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.
Bees aren’t the only winged pollinators in the gardens though.
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.
Syrphid flies, bee flies, and other bee-like mimics can be observed visiting the flowers in the garden too.
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.
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.
Even this mosquito-like insect is drawn to some of the flowers.
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  this year.
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.
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.
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.
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‘.
They are almost impossible to capture with a camera, as they barely sit still long enough for the shutter to release.
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.
Regardless, the poppies were very popular with this species of bee.
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.
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.
Everything loves these gloriously sunny, and radiant flowers.
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.
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.
Checkerspots (Euphydryas chalcedona) are prevalent in the gardens too.
Sharing the same flowers, an American Lady butterfly (Vanessa virginiensis).
Unfortunately, where the pollinators thrive, the predators also lurk. Pollination, in our gardens at least, is risky business.
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.
I’m actually quite surprised at both the prevalence, and the variation in coloration of our crab spiders this season.
The next poor unsuspecting pollinator to approach this flower is in for a surprise!
In the orchard, another one of our honey bees didn’t see what else was lurking among the poppies until it was too late.
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.
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.
Aphid-hunting Lady Beetles, albeit inadvertently, can also move pollen from plant-to-plant.
These small black beetles appear predictably each year on the Encelia flowers.
Beyond the bees and beetles, we’re also finding lots of Katydids among the flowers.
Quite a few Katydid nymphs too, especially on the native poppies.
Like the Katydids, grasshoppers aren’t principle pollinators, but they may still inadvertently transfer pollen between flowers.
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.
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.
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.
The diversity of pollinators hard at work in your garden might surprise you!
 Eric Mader, Matthew Shepherd, Mace Vaughn, Scott Hoffman Black. 2011. Attracting Native Pollinators: The Xerces Society Guide Protecting North America’s Bees and Butterflies.
 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.
 Jonathan Koch, James Strange, and Paul Williams. Bumble Bees of the Western United States. U.S. Forest Service, and the Pollinator Partnership.