Floral Visitors 17

Cichorium intybus

The flowering season is nearly over, and the number of flowering plants are few. Pollinators are foraging as much as they can before Winter and the first hard frost. Most bees will not survive to Spring because they only live from Spring (or late Winter) to frost: mating after emergence from their nest, building a nest of their own, laying eggs, and provisioning the nest with food for when the young bees hatch (not necessarily in that order). Flies and butterflies vary, some can overwinter while others have life cycles not strictly dictated by the seasons.

Cichorium intybus and Halictus sp.

The flowers of the nonnative chicory continue to bloom, providing a reliable source of pollen and nectar to various bees and possibly other pollinators. The flowers of chicory typically last only one day, but the cool conditions have allowed them to last at least two days, and not fully closing during the day allowing an extended open window for pollinators to visit. Halictus, a large genus of solitary and eusocial bees, is one of the more common genera of bee I have observed here in a variety of flower types. This male appeared to be resting or waiting for some other reason before leaving, allowing me to take some fine photos of him. I am sure he is a male because I can count 13 segments in his antennae, females have 12.

Calendula officinalis with a syrphid fly

Calendula is another nonnative, much less invasive (though it has the potential to naturalize), and has attracted some visitors. Flies appear the most interested, bees to a much lesser extent. These are planted around the perimeter of my rock garden, but in all there are few plants in bloom which probably has a lot to do with why bees are so reluctant to forage on them at any meaningful rate.

Hypochaeris radicata

Much more invasive than the previous two, Hypochaeris radicata is a honeybee favorite that continues to bloom throughout the day since it has been so cool. There aren't that many flowers in bloom, but they are still being worked by honeybees all day so long as the weather is suitable. They are superficially similar to dandelions (Taraxacum), except they flower taller, averaging 16 inches. Other morphological characteristics also separate this plant from dandelions: solid ridged stems (Taraxacum are hollow), rough hairs on the leaves, and wider rays. There are also fewer florets in each inflorescence, easily seen when compared side-by-side. Here in SW Oregon, dandelions flower very early in the year, while Hypochaeris flowers from late Spring to frost.

Hypochaeris radicata pappus

Aside from the difficulty of removing the root fragments (each fragment left in the ground when pulling the plants results in more plants), the plants spread aggressively by seed. Similar to Taraxacum (except by having longer pappus), the seed are distributed by wind. I have also observed small birds eating the seeds, potentially distributing the seeds even farther than wind would allow.

Hypochaeris radicata seedlings

The gravel which surrounds my house and comprises the driveway is an excellent way to grow weeds. After the first big rain of the fall, one can see where the seeds of Hypochaeris have fallen. This could have been produced by a single plant, perhaps by apomixis (follow the link for an interesting article on the phenomenon of apomixis, or asexual seed production), illustrating the aggressive nature of noxious weeds. This is very annoying. One area of the gravel has no seedlings as a result of seed from an old water softener which we had removed. I am unsure which is worse, the salt or the weeds. The weeds provide forage for bees. On the other hand, Hypochaeris seems unable or unwilling to compete heavily with the grasses, thus not spreading as aggressively in vegetated areas like the blackberry or starthistle.

Erica carnea with Apis mellifera

One of my small Winter heaths is in full bloom, earlier than previous years, providing interest and forage to honeybees. I have never seen the honeybees so interested in the heath here, much to my delight.

Cucurbita pepo with Apis mellifera

Ironically, the Winter squash plants have died but the Summer squash continue to bloom. We have a few gigantic zucchini which we are for some reason allowing to continue to grow to enormous proportions. Honeybees love squash pollen.

An unrelated note on honeybees: I have sometimes seen the Latin name spelled "Apis mellifica." This is wrong, yet the spelling finds its way into books and countless herbal remedy websites. Most honeybees are actually subspecies of A. mellifera, including the "killer bees" which are hybrids of two subspecies (A. m. scutellata × A. m. mellifera). Other honeybees in the Apis genus include the Asiatic honeybee (A. cerana) and the giant honeybee (A. dorsata) from SE Asia.

Water strider

Found this strange insect in the rock garden. It's a winged water strider, though at first I thought it was a walking stick. They are predatory, feeding on smaller insects. What it is doing in my rock garden, far from any standing water, is beyond me.

Geranium sanguineum

One that I haven't observed many floral visitors, but continues to bloom is the bloody cranesbill, Geranium sanguineum. The plant has grown quite large, and has flowered almost continuously since Spring.

Pteridium aquilinum spore pattern

Last week I posted about some ferns and conifers in the area. I had incorrectly and naively identified a fern as the Oak fern, Gymnocarpium dryopteris. Though this superficially resembles the Oak fern, the characteristics are quite different. The common bracken, Pteridium aquilinum, produces spores around the margins on the undersides of the fronds as seen here. The Oak fern produces clumps of spores not on the edges.

An interesting characteristic of bracken is that they produce a sugary substance similar to nectar from extrafloral nectaries located at the bases of the major branches of the leaves. These serve as ant attractants. The ants protect the bracken from herbivorous insects. This is a form of mutualism. I have an old book on bee plants that claims to have received reports of honeybees visiting these nectaries during times of dearth. I have not observed this, but I have not spent much time observing the bracken.

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The following photos were of a single umbel of the wild (and invasive) carrot, Daucus carota. Plants in the Apiaceae are frequently cited as good plants for attracting beneficial insects. The tiny florets are available for any insect, large and small, to imbibe. In these images I can see a small vespid wasp (not a yellowjacket or paper wasp), a solitary bee (Osmia?), and a variety of other tiny bees/flies. In one photo I counted seven foraging insects. Can you find them?

Daucus carota with floral visitors

Daucus carota with floral visitors

Daucus carota with floral visitors

Daucus carota with floral visitors

Daucus carota with floral visitors