Sunday, September 13, 2015

Floral Visitors 16

Hylotelephium spectabile with a honeybee
This is the time of year when the days have become noticeably shorter and, for some, cooler. The latter is not true here in Rogue River; after a brief cool period with a bit of rain it has jumped back into the 100°F range and is again dry as a desert.

The approaching fall (at least I keep telling myself it's approaching!) brings a new phase of the garden and a shift in behavior with pollinators. While Spring and the first half of Summer was very profitable for most pollinators, the nearing of the end [of the flowering season] causes some insects to be less discriminating in their selection of floral resources. Many native bees are already highly adaptable and will work a variety of flowers per foraging trip, typically each female gathering her own resources for her own nest.

Honeybees on the other hand, acting as individual cells of a superorganism (the hive), only forage like the solitary bees in these late months. Earlier in the year they are more-or-less focused on the biggest provider of resources and forsaking everything else that isn't flowering on a field scale. This is what makes them so good at pollinating crops. Yet this time of year accompanies a decline in diversity of floral resources in this region, forcing honeybees to adapt. This shift in foraging behavior is well met with a variety of fall-ish blooming plants that are adapted to flowering after the Spring and Summer flowers are going or gone, thus mitigating competition from other flowering plants.
Hylotelephium spectabile with a honeybee
The beautiful Hylotelephium spectabile (formerly Sedum spectabile) is one such late bloomer that in large groups attracts [figurative] tons of bees late into the day, even after the sun has dropped to the point that the plants are in shade. This is a sign of a plant that bees really love! Many flowers, once out of the sunlight, are then miraculously uninteresting to honeybees and other small bees. This could be that the loss of direct sun has made the spot unfavorably cold, or the heat from the direct sunlight is required to release floral fragrances that attract bees. Whatever is attracting these bees to these flowers does not require direct sunlight. I hypothesize that the flowers are rich in nectar, so much so that the essence is carried into the air.
Hylotelephium spectabile with honeybees
Though I do currently possess one specimen of this species at my house, these photos are of a large grouping of plants in my parents garden. My single specimen has attracted nothing that I am aware of, but I am hoping it will someday spread to attain the fame these plants are relishing. Reports from my step-father-in-law (lol) reports that earlier in the day, before I was there, the flowers were covered with moths as well as bees.
A black syrphid fly (Pipiza sp.) on a leaf of Hylotelephium spectabile
While watching the bees, I couldn't help but notice this small black fly, a syrphid in the genus Pipiza. It was flying below the flowers from leaf to leaf. Syrphids are well known as beneficial to gardens, primarily because their larvae eat aphids. I believe this fly was searching for aphids to lay its eggs near. Hopefully it found a few aphids. The adults grow to become pollinators. This is why aphids are good!

I recorded a video of the bees working on the sedum, apparently unaware of my presence:
Bees foraging on Hylotelephium spectabile

Dry field, chicken coup
Meanwhile, back at home, this is what our Summer is. Dry, hot, and largely dead. Most of the native flora of the region is done flowering. What is in flower is mostly located near water (plants by streams and rivers) or at higher elevations (like the subalpine flora of the semi-nearby Mt. Ashland, which I've yet to visit!) There are a couple exceptions such as Trichostema lanceolatum and Madia elegans. Nonnative angiosperms in bloom include but are not limited to Centaurea solstitialis, Cichorium intybus, Daucus carota, and Hypochaeris radicata are all still blooming, far outnumbering the natives yet yielding resources to a large variety of still-active pollinators which seem to be growing in number as the days get shorter.
Madia elegans with a skipper (Ochlodes sp?)
Regardless of all the attention the nonnatives are getting, Madia elegans remains a reliable morning resource for many pollinators. Recently, since the smoke has dissipated,  I have seen an increase in these small butterflies. They are active on a wide range of plants, from Madia and Hypochaeris to Calendula and Nepeta. As you read further down you will see a sampling of how active they are at this time.
Madia elegans with a plant bug
Along with butterflies, a variety of plant bugs and small beetles have been notable visitors to many flowers. During the busiest and most floriferous section of this year I neglected to include these diminutive floral visitors here and chose instead the variety of native bees that I could capture on "film," but they have been there all along. As pollinators they are much less efficient and probably much less effective than the main types of pollinating insects (Hymenoptera, Lepidoptera, Diptera) because they tend to just sit in one place and feed. They do move between flowers, but the rate is likely to be fairly low. However, only a single grain of pollen is needed to produce a seed, so in that perspective the potential is there.
Conyza canadensis inflorescence
Conyza canadensis (syn. Erigeron canadensis L.) is a tall annual native throughout most of North and Central America. It is known colloquially as horseweed, Canadian fleabane, coltstail, marestail and butterweed. It was one of the first plants to develop resistance to glyphosate, signaling that it is very adaptive and probably has a very wide gene spectrum. In this region it is a common sight on roadsides, leading one to believe it is an invader like the noxious Lactuca and Rubus. This species grows to around sixty inches, possibly six feet if the conditions are right. They are tall and statuesque, I often wonder about their potential as a garden plant for their sculptural qualities.
Conyza canadensis with plant bugs
The highly branches inflorescences give the plants a club-like appearance at a distance. Close up you can see that the branches end in tiny white daisies, less than a quarter inch across. The seed is distributed by the wind via a fluffy pappus similar to other weedy relatives. Looking closely at the picture I discovered that most of the flowers have small inconspicuous plant bugs attached. I hadn't seen them when the plant was right in front of me! Whether they are floral visitors or sap suckers is a mystery to me. Though while I was on the side of the road walking towards this stand I did notice a large butterfly moving around the plants, but I could not confirm if it had landed on any of the small flowers. If I had to guess, I would say this plant is not wind pollinated and instead requires insects for at least part of it's reproductive cycle. Also considering the plants adaptability, I would say cross-breeding is adventitious over apomixis for the sake of keeping genes varied and thus retaining the wide genetic spectrum. Just a hunch.
Achillea millefolium with a small bee
The native yarrow, the naturally distributed plants out in the field, have long since gone to seed. This is from a large patch I had planted from seed a few years ago around our vegetable garden. It flowers much later, and is much more vigorous than the wild "selections." Few pollinators are attracted to the flowers, mostly small or otherwise short tongued insects like flies and small bees like the shallow tiny daisy-like flowers. Bees are actually the last I'd expect to see on them, even in a large planting.
Achillea millefolium with a katydid
Katydids, sometimes known as bush crickets, are familiar yet rarely encountered insects to many gardeners. They are related to crickets and grasshoppers, but whether they are friend or foe is open to debate. I do think they occasionally eat garden plants, but they are territorial creatures and tend to be alone so the damage is negligible. More often, I have seen them hanging around or actually feeding on flowers rather than destroying them. i consider them to be beneficial in some way, though it is unclear how exactly. Some of them are predators and eat other insects. They are undoubtedly a food source for larger animals like bats, birds, frogs, and lizards; all of which are fairly numerous here. They also make a characteristic sound at night, sounding like "katy did, katy didn't" that most people mistake for crickets or cicadas, both related. (Hear a sound clip here.)
Skipper on Cichorium intybus
One of the better tolerated invasive weeds is Cichorium intybus, otherwise known as chicory. I am fond of it's ephemeral blue flowers, and of the young leaves in salads. The plants are nutritious and good for livestock, unlike other weeds that are toxic or harmful to animals. The thick taproot (I've pulled one that was over two inches thuck!) is used as a coffee additive, or a caffeine free coffee substitute that is about as similar to coffee as hot orange juice. I allow these to grow wherever they wish, a bane to all native plant enthusiasts.
Abelia floribunda with a honeybee
At the local Palmerton Arboretum, few is in bloom. The Abelia has been in bloom for over a month, perhaps two. Butterflies and a variety of bees visit the flowers continuously. Honeybees just rob the nectar by biting holes in the sides of the flowers as seen here. I watched for about five minutes as they did this. The flowers are better shaped for butterflies and, perhaps at night, moths.
Agastache foeniculum with a honeybee
The licorice mint is nearly done, but a few florets seem to just pop out of nowhere. They are still a favorite of bumblebees and honeybees, both of which seek them out regardless if a plant only has a single functioning floret.
Nepeta cataria with a sweat bee (Lasioglossum?)
Around the garden the catnip plants, so large they are more like herbaceous shrubs, continue to flower despite looking haggard and dried out. They are said to be short lived, but I've had mine for years now. One small plant has died, the others have died back a bit but look good otherwise.
Nepeta cataria with a sweat bee (Lasioglossum?)
Honeybees, butterflies, and a variety of flies are nearly constantly found on the flowers. Yet the most encountered insect are these small sweat bees in the genus Lasioglossum. This is a small bee, sometimes eusocial, that makes it's nests underground. They are particularly fond of the catnip, yet particularly difficult to photograph (these three pictures were the good ones out of two dozen). I identified them to be Lasioglossum, but it is just as likely that they are instead the closely related Halictus (strong resemblance). Bee identification is difficult at best, much harder than plants. Plants stay still for a picture. Bees think I'm trying to kill them so they flee, especially the native bees.
Nepeta cataria with a sweat bee (Lasioglossum?)
Echium vulgare with a skipper
Inside the garden are the biennial or sometimes short lived perennial Echium vulgare. Skippers, as mentioned earlier, are now very numerous and working a variety of plants, including this one. As suggested for many in the Boraginaceae (borage family), I had cut the plants down by about two thirds to revive them and encourage more flowering (gloves are recommended for that task). 
Echium vulgare with a honeybee
Not only butterflies but bees remain obsessed over the nectar-rich Echium vulgare.
Buddleja davidii with a skipper
Back at the Arboretum, a butterfly works the aptly named butterfly bush. I have mixed feelings about this plant, mostly because it is a noxious invader of riparian habitats and this park is located by a large creek. I only hope that it is a sterile form. The good news is that the creekside habitat is already dominated and taken over by the blackberry. Crisis averted.
Buddleja davidii with a honeybee
A solitary honeybee worked the flowers of the butterfly bush alongside the skipper. I was surprised to see that she did not rob the nectar, but was able to reach it from the flower opening. Looking at the uppermost flower now, I can see what looks to be the nectar in the floral tube, at a level where a honeybee could reach it. This also illustrates the reason why butterflies like the plant so much, it is very rich in nectar and flowers when little else is flowering in such profusion.
A skipper rests on Antirrhinum majus
Back at home again I observed this butterfly perched on a volunteer snapdragon. It did not attempt to feed on the flowers, in fact I think snapdragons are quite useless as pollinator plants here. In four or five years I have only once seen a large carpenter bee pry the flower "mouth-parts" open to get at the floral goods. The remainder of the time I have seen bite marks at the bottom of the flowers, but even that is not common. Yet they still set loads of seed, some of which germinates. I'll admit they are easy, and the deer do not touch them (just like the pollinators).
Agapostemon (?) sweat bee on Helianthus annuus
I may have shared in a previous post about the sunflowers that volunteered in out veggie garden. The first flower to bloom is the largest. After that, more flowers are born out of the leaf axils of the uppermost leaves, each smaller than the last. This is one of the smaller flowers being visited by a very shy metallic green sweat bee. I had to sneak up on her more than once, she kept flying away!
Agapostemon (?) sweat bee on Helianthus annuus
This bee, if it is the same species I have observed in the past, is also fond of the native sunflower relative Wyethia as well as Madia elegans. My guess is that this bee is dialed in for yellow daisies. I would be curious to find out if there is a nutritional similarity between sunflower relatives compared to mint relatives, the latter preferred by Lasioglossum (or maybe it was Halictus). Discovering these differences in preferences is one of the most rewarding aspects of anthecology as a hobby.
Chamerion angustifolium
I will leave you now with a very strange looking flower, commonly known as fireweed. Honeybees love it. I have spread seed of this plant, but I believe I will have to wait for a fire for it to germinate. Maybe it is best not to see it grow in my garden. So the moral of the story is: Don't bite the ass of the cow that feeds you. Because why shouldn't that be the moral?

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