Saturday, April 18, 2015

Floral Visitors 9

This week has been marked by excellent sunny weather, not too hot, not too cold. Many bees and other pollinators have been out, including many that I had not had the opportunity to photograph. These include bumblebees visiting the flowers of the multiple Pulmonaria's and Polemonium caeruleum, with a wide variety of bees visiting Symphytum, Brassica rapa var. perviridis, Acer's, Plectritis, and more. Still, I consider myself lucky to have photographed (or in one case, filmed) the following observations. 

Photographing pollinators is sometimes a game of patience, or sometimes just plain luck. One must be still and calm, slow to avoid scaring off the subject! Many bees and other pollinators are very skittish and will flee when you approach, to them a large mass moving towards them is often not a good thing. Sometimes sitting and waiting is the only way to see what types of insects visit the flowers of a given plant, though there is always the chance to see nothing. Sometimes just being there may keep some bees away, I've noticed on a few occasions that my very presence will cause a particular branch of a flowering fruit tree (the one I'm nearest) to be completely devoid of pollinators.

Calochortus tolmei with a black bee
I was lucky to spot this bee in the newly opening flowers of Tolmei's star-tulip (Calochortus tolmei). However, the bee does not appear to be there to forage, because the pollen has not yet dehisced from the anthers. Compare the anthers of the flower above to the one below, note the blue-grey pollen on the picture below. This bee, also one I had seen in the flowers of Narcissus, had appeared to be in the flower for shelter, maybe overnight because the flowers close at night.

Calochortus tolmei
I have observed bees of different types visit the flowers in the past, but visits seem to be relatively few. This may be because the plants do not seem to reproduce asexually (bulb divisions) very often if at all. While many will sometimes grow near each other, they often only have a few flowering individuals. This low flower density may explaine the low visitation rates that I have observed. I know this is a widespread species, extending south into California, I am curious to know if there are clumping forms in different regions or if this growth habit is typical for the species?

Lomatium utriculatum with a small bee and beetle (see video below)
Just after I photographed the Calochortus pictures, I turned around to see this small bee and beetle on this small Lomatium. This is the first time I had seen a bee on any Lomatium, previous observations were of flies and a few moths (below). Keep in mind the inflorescence is about 1.5" and maybe 5" off the ground. I recorded this observation here:

Lomatium utriculatum with a tiny moth with long antennae
Many of these small moths with disproportionately large antennae were visiting the flowers of Lomatium utriculatum. I had to creep in with the camera slowly, as they were very weary of my presence. The full sun made the flowers overexpose a bit, a good reason to avoid full sun macro photography.

Veronica umbrosa 'Georgia Blue' with a syrphid fly
Though I have occasionally witnessed bumblebees on this Veronica, the majority of the visitors are flies, particularly syrphids. They are mainly interested in the highly accessible nectar, the anthers yielding little pollen. Hoverflies large and small visit these flowers, which cover the entire plant. This plant shares the bed with countless bulbs, including the Chionodoxa's seen in past posts. I had seen aphids on the scapes of a few of the bulbs, but recently there have been no sign of them. This could be attributed to the syrphids, whose larvae seek and destroy aphids.

Veronica umbrosa 'Georgia Blue' with a carrion fly, Chrysomya sp.
Carrion flies, or blue-bottle blow flies, were the other most common visitor. This are extremely fast flies, able to fly away in an instant with no warning. This made them extremely difficult to photograph, but not difficult enough  I suppose. The presence of these flies suggests how exposed the nectar is on these flowers. From where the flies are feeding, it appears the nectar is secreted at the base of the petals near the white ring in the center.

A large syrphid on Phlox subulata 'Blue Emerald'
Right next to the Veronica in the same bed is this moss phlox. It too has shown to be of interest to hoverflies, but to a lesser extent. Its floral morphology suggests Lepidoptera pollinators, but the presence of this fly contradicts that assumption, unless the fly is eating pollen instead of reaching the nectar. I must dissect one of the flowers to see if I can determine where the nectar is secreted, that is a definitive way to determine the most likely true pollinators. If the nectar is secreted deep down the corona, then it will require a long proboscis to reach it.

Alyssum montanum 'Mountain gold' with pollen eating mites
Next to the Phlox that is next to the Veronica is Alyssum montanum. This plant has also been of some interest to syrphid flies. What was really interesting to me was the presence of these tiny red mites, mostly concentrated on the anthers! I had never thought of mites as pollinators (perhaps they are indeed NOT pollinators) but here they are showing great interest in the pollen of these brassicaceous flowers. I strongly doubt their ability to pollinate the flowers, particularly because their small size and there is little reason they would visit the receptive tip of the stigma, let alone with any pollen to deposit onto it.

Quercus sp. with pollinators??
The oak trees are leafing out, and the flowers come with the leaves. The male flowers are borne in an inflorescence, specifically a catkin, while the females are tiny acorn-like cones (which upon fertilization will grow into acorns). The male flowers appear high up in the crown, while the female cones appear at almost any position. The trees are primarily wind pollinated. I noticed some movement high up in one of the trees earlier in the week, there appeared to bee bees (or something similar) moving from one branch to another, then another, at long intervals. This is not wasp behavior, so I used the zoom on my camera to get a better look. I combined the photos, and added arrows to highlight what I saw. Number 1 shows the back wings and a thorax of a bee or fly on a cluster of male catkins. Number 2 shows a clearer image of a male catkin. Number 3 shows a bee flying away from a flower cluster. If only the flowers were closer to the ground I could have gotten a clearer shot!

Hyacinthoides hispanica with honeybee
Bluebells are in flower now, and while they are more or less ignored in shady dispositions, they are attractive to bees in the sun. Bumblebees and honeybees are most common, while a few flies and solitary bees were also there.

A honeybee with full pollen load on Hyacinthoides hispanica
Bees were able to obtain both pollen and nectar from the flowers, often going upside down to get inside. This is curious behavior, quite similar to their behavior in Hyacinthus flowers.

Solitary bee on fruit tree (Prunus sp.?)
For the first time since we've lived here, this mystery fruit tree has flowered in profusion. We do not know what it is! We suspected it may be some type of cherry, it has been known to produce a few inedible mostly-seed tart bitter "fruits", even the birds ignore them. Yet this year, it has attracted the attention of countless bees, flies, beetles, and butterflies. It is sweetly scented, unlike our plum trees which were somewhat sweet, but musky.

Honeybee on fruit tree (Prunus sp.?)
This is an aging worker, as evident by her frayed wing tips. She was also slower to move to the next flower than most of the honeybees, enabling me to take a photo of her. Honeybees are surprisingly difficult to photograph, depending on what they are foraging for. If they are foraging for nectar, they will be easier to photograph generally because their bodies are still while they reach in to get at the nectar. When foraging for pollen, they move quickly from flower to flower.

Solitary bee (Nomada) on fruit tree (Prunus sp.?)
There were many interesting solitary bees on this tree, many of which I was unable to photograph. This small bee resembles a wasp, but differs in that it is covered densely with hair. The position of the wings is also an indicator, wasps tend not to fold their wings over, though this isn't a guarantee.

Tiny beetles on fruit tree (Prunus sp.?)
These tiny beetles were on many of the lower branches. Their markings were beautiful, though I must point out that they were so small I could not appreciate them until the photos were on the computer. These beetles were no larger than a large grain of rice.

Nomada on fruit tree (Prunus sp.?)

How many insects can you find?

Sunday, April 12, 2015


Here is a snapshot of what is in bloom here now at this time. I will keep descriptions short, as time is short for me today. This will be a mix of natives and plants from my garden. Yesterday I was with my daughter while my wife and her mom went shopping together (she needed a break), so my daughter and I went out for a walk. My daughter, Zia,  loves flowers, and she loves to pick them! I do let her pick the dandelions in the "lawn", but we have been trying to teach her not to pick flowers out of the garden! I often have my camera with me when I am on a walk, and it got me thinking: Why take pictures? Why not let her pick them? Well, I am not really excited about the idea of letting Zia go pick the flowers of the Epimedium or Cynoglossum, and we will continue to enforce (to the best of our ability) the "No pick" rule. What I told her was this: "If we pick a flower, it will be gone forever. If we take a picture, it will last forever!"

Iris chrysophylla, flower opening
Iris chrysophylla
Iris chrysophylla
Iris chrysophylla, or hybrids thereof, grow out in the open fields around where I live. They form large clumps, quite different in appearance from the typical rhizomatous irises most often encountered in stores. The flowers of these, in my opinion, have much more substance than the tall bearded irises and dutch irises.
Symphytum officinale var patens
Interestingly, the color of these flowers are different than they were last year. I started these plants from seed last year, or maybe the preceding Autumn (of 2013). They bloomed last year, much later in the year, and were not so deep in color. I am pleased with this! Hopefully the bees are as well, last year they loved the comfrey and sought it out with intent.

Cynoglossum grande
A few of the hound's tongue's are still in flower, hinting at a wide range of genetic variability. A longer bloom period, as a species, may ensure successful pollination in a climate that changes from year to year. Every Spring bring something new, and pollinators (bees, in this case), adapt to the conditions. This may mean that they forage earlier in some years than others, or that one plant will be more enticing than another. It's a gamble. Plants that can or do adapt to changing conditions have the best chance for long term survival. 

Phlox subulata in the rock garden
Tiarella sp. in the forest garden
Scilla siberica, still blooming strong!
Epimedium × rubrum
Epimedium × rubrum close-up
Epimedium has been s genus that I have been lusting over ever since reading about it in "The Explorer's Garden: Rare and Unusual Perennials" by Daniel J. Hinkley. Read about the genus and species on the Pacific Bulb Society wiki, I wrote the page on Epimedium. Pictured above is the most common selection available, a ground cover that can be an aggressive spreader but useful under trees where nothing else will grow. The small ephemeral flowers are best appreciated if the foliage is cut to the ground in winter. Pictured below is a beautiful mounding selection, 'Amber Queen', with large spider like spurred flowers. In the close-up shots of both Epimedium selections, you can see the nectar in the spurs, where it is held awaiting a pollinator.

Epimedium 'Amber Queen' close-up
Epimedium 'Amber Queen' panicle with Scilla siberica and Viola odorata in the background.

Viola glabella
Smooth yellow violet, so it is called, is a forest understory herb that grows in moist leaf litter. The leaves are smooth, without hairs, and often slightly toothed. The plants can grow up to a foot tall, and as wide. It differs from V. praemorsa (below) mostly by leaf morphology, as well as habit and habitat.

Viola praemorsa
The prarie violet, so it is called, grows in open clearings with Horkelia and Prunella, among others. The petals are narrower than V. glabella. Also, the leaves are finely hairy with smooth margins and a rounded tip. Subsp. praemorsa has toothed margins on it leaves, but still has the fine hairs. Grows to six inches, often shorter here, to three inches.

Ceanothus cuneatus
Astraeus hygrometricus
The false earth star is a fruiting body of a type of fungus. It appears atop the soil as a ball, then depending on the barometric pressure or humidity the "star" opens and the spores are released. The spore ball can be seen as the brown lump in the center. This species flourishes in poor rocky soil where not too many plants can grow.

Erythronium hendersonii
Henderson's fawn lily is still in bloom in some areas, mostly in the forested areas. The plants in more exposed sites flowered earlier, and have already begun to set seed (see picture below). This plant is also taller, almost sixteen inches, the scape apparently protected by the shrubbery and other plants in the understory.

Erythronium hendersonii seed pod

Floral Visitors 8

Upon getting a few hours outside, I was able to observe some pollinators in relative action! Despite the cold sunless weather, some bees and other insects have managed to make use of the brief periods of relatively "nice" conditions. My honeybee hives (I just split the hive about a week ago) seem busy with activity, Arbutus menziesii and Acer macrophyllum being in full flower (among others). I recently discovered what seems to be a fungal infection of Ascosphaera apis (chalkbrood) in at least one of the hives, for which there is no treatment, so I hope that all of the new plants coming into bloom will aid in the bees good nutrition and help them combat their malady!

Acer platanoides 'Crimson King'
About a dozen or so of these medium sized maple's grow in the parking lot of my workplace. Though the weather has been poor, I have still seen bumblebees and honeybees visiting the flowers. If the photo looks strange, it is because I had to remove a flowering piece to bring into the relative stillness of my car. It has been very windy lately, making photography of plants very difficult. I am regretful that I was unable to photograph a bee on these flowers, but knowing they were there is enough for me. There is a single tree of Acer platanoides near my house, though I have never witnessed much pollinator interest in it, besides a few small beetles. It is fairly isolated from any other flowering plants (while it is in flower), so this isn't too surprising.

Anemone coronaria
 A low scorer for pollinator attraction in my garden has now become useful as a shelter and a food source for spotted cucumber beetles (Diabrotica undecimpunctata). I do not mind the over-the-top splash of color these flowers bring to the garden (st nearly three inches across when fully open), and I am pleased that they can serve a further purpose at this time. They have never set seed for me, perhaps they are a sterile selected form or perhaps they do not receive adequate pollination services.

Ceanothus cuneatus
 Can you find the spider? Though the flowers of Ceanothus cuneatus across the landscape are going past their prime, they are still impactful visually and remain to attract a wide array of small pollinating insects. Upon accidentally bumping a branch, countless tiny flies or gnats were stirred and flew around until finally resettling on the flowers somewhere, hidden from view. The flowers certainly attract many different pollinators, the flowers are most attractive to the smallest types of pollinators. Larger bees like Megachile and Bombus will work the flowers when they are first opening, and many small beetles and flies will work the flowers over their bloom. But there are also many tiny bees that have shown interest, easily mistaken for small flies. The smallest bees are some of the hardest to photograph, requiring the camera to move very close, but they tend to be skittish and will quickly disappear if they feel threatened!

Mahonia aquifolium
This bee was not foraging at the time this picture was taken, but rather taking refuge. It was overcast, and possibly too cold for the bee to fly. Many bees, including honeybees, require a minimum temperature to fly. Some of the larger bees, like Bombus (bumblebees) are able to keep "warmed up" by vibrating their flight muscles. While smaller bees may not have this ability, they may be able to stay warm enough when they are in flight (think how you generate heat when you exercise) but cannot generate warmth when they land, so may end up stuck like this if they don't make it back to their nest in time. If the night is dry, they will warm up the following day and be on their way. The flowers do afford a minuscule amount of protection and warmth, absorbing and reflecting heat from the sun.

Prunus sp.
A late blooming plum-like (or possibly a cherry) tree in my yard is always the last of the fruit trees to bloom. It has in the past produced tiny bitter "mostly seed" cherry-like drupes, but the birds often get to them first. It could be that there are no other flowering fruit trees to cross pollinate with, or that it is itself a pollenizer, a tree planted specifically for the purpose of providing pollen to other fruit trees that require outcrossing. After removing a large blight-stricken branch last year, this tree appears to be flowering extremely well! My honeybee hives are situated less than twenty feet from the tree, and I have seen plenty of honeybees on it when the sun is out. Many flower flies (syrphids) have also been attracted to the flowers, even under less-than-perfect weather conditions.

Prunus sp.
Maybe it was due to the relatively low temperature at the time, but this bee let me take several dozen photos of it! I watched as it moved around slowly to imbibe nectar, perhaps curious as to what I was doing. Solitary bees differ from honeybees by a variety of reasons, with one notable characteristic in particular. Honeybees have specialized hairs on their hind legs called corbicula, but most often called "pollen baskets", that are open cavities surrounded by a "basket" of hairs to hold the pollen. Most solitary bees on the other hand have what are called scopa (see the picture), which consists of a dense patch of often branched hairs that hold the pollen. Honeybees use nectar to moisten the pollen and pack it into their corbicula, while most solitary bees store the pollen in its dry form in their scopa, which can be either on their legs or sometimes underneath their abdomen. This can help explain why solitary bees are more effective pollinators on a bee-per-bee basis of native plants and crops, the dry pollen in the scope will be more likely to land on a fertile stigma than will the wet packed pollen in a honeybees corbicula.

Saturday, April 11, 2015

Floral Visitors 7

The weather this week has been fairly drab - overcast with nighttime lows nearing freezing. Bees have had little opportunity to forage, and my daughter and I have been sick so my opportunities to observe and photograph floral visitors has also been reduced. Nonetheless, I keep my camera with me almost all the time, so if an opportunity arose, I would (hopefully) be able to capture it.

Lomatium utriculatum

Flies have been the dominant floral visitors this week, well adapted to coping with adverse climatic conditions. They are apparently unbothered by cold and wet, possibly even appreciating the lack of competition or even perhaps predatory distractions. Contrary to the popular belief that flies are attracted to putrid smelling flowers, they are attracted to sweet scents as well. In some cases the smell of rotting flesh (like in some of the aroids) attracts flies who wish to lay their eggs in rotting materials (logs, leaf debris, etc.) or dead animals. Upon landing on a repulsive smelling flower, adult flies inadvertently serve as pollinators, wandering around the putrid inflorescence looking for a place to lay their eggs, and spreading pollen as a result.

Lomatium utriculatum
Flies are considered generalist pollinators, and are attracted by a wide array of floral characteristics. Some eat pollen, some drink nectar. "Fly flowers" in the United States are typically shallow and small, meaning that the nectar doesn't require a long proboscis to reach it. Many flies, as well as beetles, have fairly short probosces so can only feed on this kind of flower. Many flowers in the Apiaceae, or carrot family, have this type of flower and are often visited by a variety of flies. Many fly flowers are white or yellow, but some are green or brown. Sometimes there is a detectable scent, sometimes not.
Lomatium utriculatum with Rhamphomyia sp.
A few dagger flies and some other flies were visiting the flowers of the fine-leaf desert parsley. The small yellow umbels are the first of the Lomatium's to flower in my yard, growing on open banks consisting of deficient alluvial soil. Ants and tiny gnats also visit the tiny flowers (only reaching around four inches in response to the local climate), but the gnats are more common when the weather is nicer. This is one of the species that inhabits Upper Table Rock.

Alyssum montanum
Colloquially known as harvestmen, the arachnids of the order Opiliones are separate from  spiders (order Araneae) by their fused body regions and single pair of eyes. I'm not sure what this one was doing on these flowers. I doubt it was interested in the floral rewards (nectar or pollen), but possibly for the solar radiance. Flowers sometimes reflect heat from the sun, a feature that attracts some pollinators or entices them to visit the flowers.

Ranunculus occidentalis
I spotted this beetle easily on the bright glabrous yellow flower of the buttercup. Beetles are mostly pollen eaters (though a few visit flowers for nectar) or are there to eat the flower itself. Many beetles are attracted to flowers as a safe haves, wither to mate or to spend the night in relative safely from predators. This one was there for the pollen, its mandibles at work. The study of beetle pollination is complicated, it is often difficult to tell if a beetle is eating the pollen or the flower itself. There have been cases where the flower eats the flowers, yet they still set viable seed, suggesting they are the pollinators of those flowers. Peculiar.

Sanicula crassicaulis
I have seen this understory forest herb on a variety of occasions, and every time there have been ants on the flowers. This small carrot relative grows to under a foot tall with a six inch spread. The tiny flowers are less than a eighth inch, 3 or 4mm perhaps. I am not well read on ant pollination, only having read once that their bodily secretions have shown to sterilize the pollen of some plants. Other roles that ants play is by protecting plants from certain pests, like mites or other sap suckers. Many plants in the Rosaceae (rose family) attract ants to them by providing the ants with nectar from "extrafloral nectaries", small excretory organs found on parts of the plants besides the flowers (sometimes at the leaf axil) that produce a sugary nectar-like liquid.

Laurus nobilis
Laurus nobilis
This bay laurel, or something close, was appropriately growing in front of a local pizza shop in Rogue River, Oregon. The shrub was trimmed to a hedge, and there were only a few flower clusters, but I watched as this fly visited several flowers. The plants are documented as being dioecious, having male and female flowers on separate plants. This plant appears to be a male, having filaments and anthers, though I did not see any pollen shed. Perhaps rain had washed it away? Nectar is secreted at the base of the ovary and seeps through the space between the petals and the ovary. That's what the fly was after.

Aucuba japonica, female
Though there are no bugs in this picture, I assure you flies were there! The Japanese spotted laurel, Aucuba japonica, is a common sight in shaded gardens here. The plants are dioecious, meaning female and male flowers are borne on different plants. This one here is a female, notice the flowers are lacking anthers. They do however provide nectar, a sweet smell emanated from the plant (though with my congestion I was barely able to detect it!). The plants can grow to an excess of eight feet, but the flowers, emerging at the branch tips with the new leaves, are a meager half inch (and that is a generous estimate).

Now see Floral Visitors Pt.2