The Amateur Anthecologist: Native Bees 2015

Looking back through all of my pictures from this year, I have caught a stunning array of different types of pollinators at work. This list is by no means exhaustive, many more bees visited my garden than I was able to photograph. Besides what I have been lucky enough to see and photograph "in the act" (good photos, anyway), I have seen bees in the genera Agapostemon, Sphecodes, Megachile, and more that I couldn't identify. This list also doesn't address every family of bee, only the ones whose species I have photographed. The bees I have photographed and named were identified by research scientist John S. Ascher (Ph.D. in Entomology, also an assistant professor of biodiversity at the National University of Singapore) through the BugGuide ID Request. Thank you, John, because I would have misidentified everything without your expertise.

So without further delay, I present to you: Native Bees!

(Also see Pollinators of 2015 posts: Lepidoptera, Wasps, Flies, and Beetles etc.)

Bees first appear in the fossil record around 100 million years ago. They evolved from predatory wasps, probably from the families Crabronidae or Sphecidae. It is unclear when they went vegan. Insect pollination, perhaps by beetles or thrips, may predate bee/wasp pollination by millions of years.

Family Apidae

The family Apidae contains many of the world's commercially important bees including honeybees, stingless bees (tribe Meliponini, social bees used to produce honey in tropical/subtropical regions in the world), bumblebees, and others. Other interesting species also inhabit this family including the orchid bees (tribe Euglossini, males collect floral oils to lure mates), anthophorine bees (tribe Anthophorini, some members are pollinators of Narcissus in their native range), and others. Most are solitary, but there are also many social or semi-social species.

Bombus

The genus Bombus are some of the most easily recognized and ubiquitous bees around, only second to honeybees. Due to their large size, and their ability to vibrate their flight muscles [when not in flight] to keep warm, they are active very early in the year when it is far too cold for other bees to venture out. This is why they are the first bees, and the very first pollinators, that I have encountered in my garden each year.

Being large bees, they have proportionately long tongues (proboscises) which enable them to reach nectar in deep flowers which may be too deep for smaller bees. They also have strong mandibles, which enables them to cheat by biting holes at the bases of very long flowers and sucking them dry, bypassing the reproductive parts. They forage on a very wide spectrum of flower types throughout the year, much more than seen in these photos.

Bombus on Erica carnea (January)

Bombus on Crocus vernus 'Pickwick' (February)

The first bees I see every year are the yellow and black bumblebees shown above (the species is hard to pin down, my photos were not detailed enough to warrant a positive ID). The large queens show up before any other bees on the Winter heath (Erica carnea), then work the large Dutch crocuses (mostly ignoring the species Crocus, perhaps since they appear to produce pollen less prolifically). The black/yellow bumblebees visit a lot of flowers during the year, but their appearance tapers in Summer when they are replaced by another species of mostly yellow Bombus that is active later in Spring and most of Summer (below). The identity of these bumblebees to species level has been a mystery to me, something I had explored in a post from July regarding specifically regarding this yellow bumblebee (see it here).

Bombus on Echinacea (July)

Bombus on Trifolium pratense (July)

With the exception of a few cleptoparasitic species (sometimes considered to be the subgenus Psithyrus), new Bombus queens build new colonies early in the Spring, usually underground in abandoned rodent tunnels or under debris, sometimes in cavities in trees (or cavities in the walls of man made structures). At first the new queen is alone, foraging for early sources of nectar and pollen, and returning them into pot-like wax containers (comparable to the cells of honeybee comb) for nectar and egg-laying within the nest. The lonesome queen collects what she needs to provision the nest and lays eggs as resources allow until a few workers are born; the workers then take over the foraging duty while the queen ceases to forage, residing in the nest to rear more young.

Unlike the perennial colonies of honeybees, bumblebees have annual colonies. Towards the end of the year (Either late Summer or Autumn, depending on the species), male bumblebees are born of unfertilized eggs. New queens are also reared, fed a bee superfood probably similar to the royal jelly of honeybees. New queens and males venture out to find mates. New queens, like honeybees, mate with several males and store all the sperm they need for the following year. They only mate a single time, after which the males die. The current years colony dies in Winter, except for the newly mates queens which will start the cycle anew the following year.

The former genus or subgenus Psithyrus constitutes the parasitic members of Bombus sensu lato. They are very similar looking to their hosts, colony building species of bumblebees. They do not collect pollen, but rather infiltrate an established bumblebee colony and killing the host queen. Utilizing a special pheromone or by aggressively defending themselves (being less vulnerable by having harder bodies and tougher joints between segments) they take command of the workers in the host nest and use them to raise their own young, eventually spelling doom for the host colony since the parasites contribute nothing to the hive. Since Psithyrus does not build colonies, they do not produce sterile workers and instead only lay eggs of fertile males and females (queens) which will over winter and seek out a new host colony to invade the following year.

Habropoda

Habropoda is a relatively small genus (44 species worldwide, compare that to Lasioglossum) of large digger bees. They are fast and loud, and quick to move from ﬂower to ﬂower making photographs very challenging with a lot of blurry grey streaks. They are a little smaller than bumblebees, and also decidedly more grey. Also, knowing how to tell the difference between Bombus and Habropoda by their distinct foraging techniques is something easier utilized than explained.

Habropoda on Prunus hybrid (March)

The identity of this bee has mystiﬁed me for years. I ﬁrst encountered this species visiting Arctostaphylos viscida at lightening speed (see my photos from April, 2014 here). The bee would be gone by the time the camera was in focus! I also witnessed it visiting a dozen Dodecatheon hendersonii before disappearing into its nest, which was dug in a bare patch of soil at the edge of a woodland by my house. That is another difference between Habropoda and Bombus, the former is lives a solitary life while the latter nests socially. Exotic plants visited by Habropoda include Muscari and Prunus, though I am sure there are more.

Ceratina

Ceratina are an interesting group of tiny carpenter bees. Their small size (less than 3/5^ths of an inch) and weak jaws limit their nesting materials to the pithy centers of herbaceous perennials and some shrubs. Broken blackberry canes are a likely nesting site, the pithy center is the ideal nest site. Females excavate a linear section from within the stem and lines it with a series of brood cells each containing an egg and some rations. Each cell is sealed and the female remains at the entrance until she dies in Winter, her body then blocking the entrance from intruders (that is love, imho).

Ceratina ♀ on Leucanthemum (June)

Females are characterized by sparsely hairy hind legs (scopae) as seen here. I have seen this same species visit the Shasta daisy two consecutive years now, while little else appears terribly interested in the easily accessible white daisies.

Tribe Eucerini

The tribe Eucerini contains the similar genera Eucera, Melissodes, Svastra, and the uncommonly encountered Tetralonia. All are known colloquially as long-horned bees due to the long antennae of the males of some species. I am certain the long horned bees I have observed on the Madia are of the genera Eucera or Melissodes, but further identification would take a dead specimen and a microscope, and I'm not terribly interested in killing a bee to discover its name.

Most genera in this tribe are ground nesting bees, coating the walls of their brood cells with a waxy waterproof secretion. In my observations the bees in my region are active early in the morning, males sleeping solitarily in Madia flowers. I am speculating that there is a connection with Madia and these long-horned bees because both are active (or in the case of the Madia, open) early in the day.

Long-horned Bee (Tribe Eucerini) on Madia elegans (July)

I wrote about these bees and their relationship with the Oregon native, Madia, in the post from July: Madia elegans.

Xylocopa

The genus Xylocopa are some of the worlds' largest bees. They are carpenter bees, making tunnels in living or dead wood, using chewed up wood to separate the brood cells. They are solitary, yet adults of some species over winter and may even occupy the same nest as their daughters the following year. In my garden, they are larger than bumblebees and conspicuously loud, their buzz distinguishable at a distance. Though they are large and foreboding, they are gentile and generally do not sting unless they are defending their nest.

The eggs of Xylocopa are the largest of any insect, some nearly half the size of the female's body. Due to this, they often lay only a few eggs in their lifetime (maybe a year or two), usually equating less than eight eggs in total. Woodpeckers are one of their predators, the birds can hear the larvae inside the wood or tree and will then peck into the nest to eat them.

Xylocopa californica on Monarda (July)

They seem to have distinct plant preferences in my garden. The plants I have seen them working the most are Salvia sclarea, Monarda, Echium vulgare and Verbena lasiostachys. They have also been mildly interested in Petunias in hanging baskets on my porch, having proboscises long enough to reach the nectar. They are also occasional nectar thieves, but not as prolifically as the bumblebees in my garden.

Nomada

The genus Nomada is one of a few wholly cleptoparasitic genera of cuckoo bee (along with Sphecodes, Stelis, and Coelioxys), so named for their reproductive strategy of laying eggs in or near the host nest, namely other bees. Due to this, they do not make their own nests and also do not collect pollen (which is collected by all other bees to feed their young), note the lack of pollen carrying apparatus on the legs and bodies of the specimens shown below. Their young simply feed on the pollen stores or nectar collected by the host which is intended to feed the hosts‘ own young.

Nomada lay one to four eggs along the eggs of the host within the hosts nest. When the Nomada larvae hatch, they are born with large sharp mouth parts which are used to kill the host larvae, as well as their own siblings (if there are any). After the ﬁrst molt, their over sized mouth parts are shed and they then possess normal mouth parts from then on. They typically parasitize the nests of Andrena, though the nests of Agapostemon, Halictus, and Lasioglossum are also exploited. Despite their potentially harmful effects to their hosts, the presence of Nomada or other cleptoparasites suggests a healthy and robust host population.

Nomada (Red cookoo bee) on Arbutus (April)

Nomada ♂ on Prunus hybrid (April)

I speculate that the two photographs here show different species of Nomada, though I can‘t be sure. The red wasp-like species on the left was one of the most common visitors to the Arbutus (madrone) this year. Despite not collecting pollen for their young, adults feed on nectar so they do contribute something in the way of pollination. I also observed the red Nomada frequently on Toxicodendron diversilobum, also begrudgingly known as poison oak. It was the only pollinator l have ever observed on poison oak (noted in this post from May).

A note on bee reproduction:

All male bees, any genus, come from unfertilized eggs. They have one set of chromosomes, and thus the queens' figurative phallus. Female bees, however, have both a mother and a father. The family tree is quite strange. Start with one: The male has a single parent, a queen. The queen has two parents (queen and male), the queens parents have three predecessors, which are descendants of five. You get the idea (1-1-3-5-8-13-etc). If you are a math nerd, you will recognize this emerging pattern: the Fibonacci sequence.

Family Andrenidae

Around 3000 species of solitary ground dwelling bees make up the Andrenidae. In general, they prefer sandy, sparsely vegetated sites. A few of the genera are crepuscular, meaning they are only active at dusk or the early evening.

Andrena

Andrena (likely a female) on Crocus 'Jeanne d'Arc' (March)

Andrena (♂) on Arctostaphylos viscida (March)

Andrena is a large genus of mining bees with a nearly cosmopolitan distribution with the most diversity of species in the Northern Hemisphere (none in Australia, Antarctica, or the extreme North). They are typically small bees, and are frequently encountered by gardeners due to their habit of nesting in lawns. In my region they are mostly active very early in the year, tapering off in Summer.
I have often seen them on Crocuses (photo above on Crocus 'Jeanne d'Arc', also see recording below). Males met in large aggregations this year on the flowers of Arctostaphylos viscida (above, right), where they were often found biting holes in the sides of the pendant urn-shaped flowers (note the holes in the sides of the flowers) to access the nectar rather than entering the flower properly. Similar "cheating" was observed on the similar looking flowers of the related Arbutus menziesii, however I did not directly observe Andrena on those flowers (see Nomada below).

Andrena are mining bees, meaning they create their nests in tunnels in the ground, often in lawns or other areas with sandy undisturbed soils. Males and females emerge from their nests around early Spring. After mating, females seek out sites to create their nests (they don't reuse old burrows). They create branched tunnels with a single entrance, and many individual chambers for laying eggs. The brood cells are lined with a secretion which soaks into the surrounding soil and hardens the cell wall, it is then polished with a special plate on the females abdomen (the pygidial plate). In each chamber, the expecting females make a small ball of pollen with a tiny bit of nectar and then lay a single egg on top of each ball. After she is done she will seal the nest and her job is done, the cycle starts anew the following year (only the newly laid eggs survive through Winter, like most American bees).

Andrena ♂ on Prunus hybrid (March)

Andrena ♀ on Berberis (syn. Mahonia) (April)

They appear to feed on a variety of different flower forms, specialization occurring less often. Besides what is photographed here, I am hard pressed to name other plants they visit due to my inability to accurately identify them in the field. I am certain that visit the fruit trees when they bloom (we have a few hybrid Prunus trees, and a few others), though a lack of photographic evidence says otherwise. Erodium cicutarium, a lawn weed I am fond of that fills an area of the "lawn" with poor rocky soil is visited by a large variety of skittish bees and flies, so I suspect Andrena to be one of the bees that forages on it when it is prevalent (I wrote about the Erodium here back in March).

Andrena on Lomatium (April)

Family Halictidae

Halictus

Halictus on Prunus hybrid (April)

Sweat bees in the genus Halictus are a fairly common ground nesting bee in my garden, with about ten species residing in the United States (200 species worldwide). They are active early in the year and even as late as October this year (see the photo of the bee on the blue Cichorium below).

Halictus ligatus on Cistus (May)

Halictus dig their nests in flat ground and then line the brood cells with a waxy secretion from a special gland at the tip of their abdomen called the Dufor's gland. They are eusocial, meaning they are often solitary in the beginning, then first generation daughters remain in the nest to care for the young (as with honeybees). Depending on the species, a nest may have a single queen and a few workers, or they may have many queens and hundreds of workers in an extensive underground colony. I suspect the climate may also play a role, where food sources are scarce it may be more adventitious to be more or less social. Climate also plays a role, cooler climates stimulating solitary behavior while warmer climates motivate eusocialism.

Halictus ligatus ♀ on Madia elegans (July)

They are active over a long period of time throughout the year, and they forage on a wide variety of plants. Aside from what is seen in these photos, they were also one of the first bees I had seen on the species Crocus.

Halictus ♂ on Cichorium intybus (October)

This photo represents the last solitary bee I saw this year.

Lasioglossum

Lasioglossum is a large genus of over 1500 species worldwide, and 400 representative species in the United States alone. They are very common in gardens (including mine) but easily missed due to their small size. Similar to Halictus, in appearance and nesting habit, they are eusocial and will nest either solitarily or socially, depending on the species and perhaps the local conditions.

Lasioglossum on Convolvulus arvensis (June)

Aside from visiting the field bindweed shown here, they were very active on Nepeta and Helianthus this year, as well as a variety of other mint relatives. As many as three bees would be working a single sunflower at once, and countless per Nepeta plant.

Family Megachilidae

Osmia

Mason bees of the genus Osmia are some of the most well known and utilized solitary bees. The species Osmia lignaria, the blue orchard mason bee, is commercially available for pollination services and shipped as dormant larvae (sold in blocks of wood or cardboard tubes). They nest in dead wood and hollowed out plant stems, typically in old beetle tunnels or abandoned wasp/bee nests. There are often vacant nests for sale at nurseries and similar retailers for the purpose of attracting mason bees. Alternatively, a mason bee nesting block can be made at home with some wood scraps and a few drill bits of varying sizes. Example.

Osmia mating on Iris chrysophylla (April)

I was lucky to spot these two bees mating on this native Iris. I hadn't noticed there were two of them until I saw the image on my computer! Interesting that despite having a male attached to her back, she is still visiting flowers and has managed to coat her head in pollen. I watched for a few minutes, then the due flew off (though I was still under the spell of the illusion that it was a single bee, they flew off attached).

Family Colletidae

Hylaeus

Hylaeus on Petroselinum crispum (June)

Hylaeus are common, buy tiny, bees found throughout North America. They have few to no hairs, and yellow or white markings on their bodies giving them the name yellow-faced bees. Similar to syrphid flies (who eat pollen), they carry pollen and nectar internally in a modified stomach called a crop. In honeybees, the crop is also known as the "honey stomach." They can easily be mistaken for tiny wasps, partially due to a lack of pollen carrying apparatus such as scopae. The few hairs they do have are branched which gives them a dull appearance. Wasps on the other hand have unbranched hairs, so they appear much more shiny.

These small bees have short tongues, but their small size allows them to crawl right inside of deep flowers with nectar that is typically out of reach from larger bees. I have seen small bees, their identities unknown, crawl deep into tubular flowers normally reserved for hummingbirds. What a treat for a hummingbird!

Bees of 2015

To conclude, I've compiled all of the recordings of bees I've managed to capture from this past year. This is a playlist of 17 short recordings of bees from throughout the year. This includes honeybees, which despite being an exotic species do earn their way in through their pollination services (and of course the honey, incomparable to store-bought honey in flavor and quality). Enjoy!