Brendan Murphy 5/21/24 Brendan Murphy 5/21/24

Happy Bee-lated World Bee Day

World Bee Day was May 20th, a day to appreciate bees for the enormous role they play as pollinators.

We all love bees for the enormous role they play as pollinators. Over a third of the food we eat is thanks to these incredibly hard workers, as well as nearly all flowers and even many trees. When most people hear about bees, they usually imagine the European Honeybee, Apis mellifera. While this is an extremely important species to us humans, they are far from the only important species of bee out there. In fact, over 20,000 other species of bees have been described! Here in the US, more than 750 species can be found east of the Mississippi River. About a quarter of our native bees are specialists, meaning they have coevolved with a specific host plant to feed from and transfer pollen between its flowers. Without these native bees, a huge diversity of native wildflowers would disappear.

This Dunning’s Miner, *Andrena dunningi*, is taking a quick rest on a guide’s hand. As their name suggests, mining bees are ground-nesters. Females dig narrow burrows, preferably in clay soil. Although they are solitary nesters, several females will often construct nests near one another. These small bees overwinter as adults in their brood cells and emerge in early spring. While many mining bees are specialists, the Dunning’s miner is happy to visit several different families of spring blooms.

Despite being the poster child of Apoidea (the bee family), the European Honeybee is actually not very representative of the rest of the bees. While a few other species have social nests (the bumble bees and a handful of sweat bees), the majority of our native bees construct solitary nests or even just a few dispersed brood cells without a nest at all. Even in these social nests, there may be several fertile females that work together to raise their young rather than a single queen. Most bees nest underground, in plant stems, or in tree cavities and pack brood cells with enough rations to feed a larva to adulthood. The female will then lay a single egg in each and seal it off. These species are usually univoltine, meaning they have one generation every year. The larvae only eat the provisions their mothers stored for them before they pupate and emerge as adults the next year

The Spine-Shouldered Cellophane Bee, *Colletes simulans*, is a Goldenrod specialist. Like the rest of the Cellophane Bees, they nest underground in dry, sandy soil. This group of bees get their name from a plastic-like wax the females secrete that they use to line their nest, holding up the walls and making them waterproof.

There are many important pollinator species- butterflies and moths, flies, beetles, even some birds and bats. All of these species visit flowers to drink from its nectar and sometimes graze on pollen, then “accidentally” transport pollen between flowers. Bees are unique in their behavior of collecting and moving pollen on purpose. Female bees collect large quantities of protein-rich pollen and carbohydrate-rich nectar to provision her brood cells. As she visits flowers, she collects pollen in her pollen basket, commonly found either on the hind legs or under the abdomen. Upon visiting a new flower, she drops off some pollen she is already carrying to make room to pick up more. This results in very high rates of pollen exchange, helping the plant successfully fertilize its seeds.

This Two-spotted Bumblebee, *Bombus bimaculatus,* is collecting pollen from a sneezeweed aster. Perhaps the best known group of native bee, the bumblebees are adept pollinators. Most species are generalists and are active the entire growing season. Thanks to their long proboscis and robust build, they are able to access flowers with concealed nectaries. They are also some of the only native bees that live in eusocial nests made of a queen and her daughters.

In 2006, news broke of a crisis to bees- Colony Collapse Disorder. Data from beekeepers showed a decline of nearly a third of honeybee populations from 1989 to 2008. Several factors were identified including over-application of pesticides, the introduction of the Varroa mite to European honeybees, and the several disease outbreaks from hive transportation. Since 2008, honeybee populations have been recovering thanks to many of these threats being identified and mitigated. While this is a great success story for the domestic honeybees, research into our native bees’ populations is only just beginning. In addition to many of the same threats, native bees also suffer from habitat loss, resource scarcity, and competition with introduced species. In very recent years, lots of important research is being published, putting native bees in the spotlight of conservation efforts.

The Pugnacious Leafcutter Bee, *Megachile pugnata*, is an Aster family specialist. Female leafcutters use their large shear-like mandibles to cut circular flakes from leaves, which she uses to line her brood cells. Rather than a single nest with several brood cells, leafcutters typically build several dispersed brood cells in dead, hollow plant stems and other preexisting holes in plants.

If you have a garden, you can help support native bees just by being a lazy gardener. Instead of pulling weeds, do a quick search to see if that plant supports native species and only remove the invasive weeds. Try to support a variety of native wildflowers. Leave clippings on the edges of the garden to provide habitat and resources to nest-building bees. And avoid using toxic pesticides- by supporting a variety of species, they may begin to self-regulate. But an easy way we can all help out the native bees is just by learning a little about them, and checking in on them once in a while. So take a moment this spring and summer to appreciate some of nature’s hardest workers for all the beeauty they make possible.

Bill Dunson 7/19/16 Bill Dunson 7/19/16

Pollinator Fields in Their Glory

In general I do not recommend trying to improve on nature beyond the boundaries of the yard since the beauty of natural scenes is often incomparable. However creation of a Pollinator Field from a portion of hay fields or pastures or even yards can provide habitat for pollinators such as butterflies and bees, while also providing enjoyment to the land owner. Such fields may be funded by USDA (US Department of Agriculture) and NRCS (Natural Resources Conservation Service). One method is to burn existing grass and weeds in late winter, then the re-growth is killed with herbicides. In May, wildflowers and native warm season grasses (NWSG) are planted with a no-till seed drill. The field pictured was planted four years ago with 4 species of grasses and 16 kinds of flowers. Some of these did not thrive, but others have done well and produce a spectacle of flowers in early to mid-July as well as a lesser display during May and later summer months.

The classic pollinators come to such flower meadows and just two examples are the orange sulphur and female black tiger swallowtail butterflies. The adults are likely mainly obtaining nectar there but the Sulphur caterpillars feed on alfalfa which is present, whereas the tiger swallowtail caterpillars likely feed on nearby black cherry and tulip trees. Bumblebees (on light lavender bergamot in photo) forage extensively in the pollinator field on the abundant wild bergamot and purple coneflowers. There are also honeybees (on purple cone flower in photo) present which is not generally a good thing. Honeybees are actually a non-native species from Europe, and as domesticated hives used to pollinate crops or produce honey can be very valuable. But wild or feral hives are in competition with native pollinators and are not desirable. In our particular setting far from crops that require pollination, honeybees are less abundant than the native bees and thus are not a major problem.

Some of the most interesting pollinators are insects such as the syrphid flies (on yellow ox-eye sunflower in photo) which mimic yellow jackets and gain protection from their predators. Other insects which utilize the field habitat range from green camouflaged katydids, to dragonflies such as the widow skimmer, to the fig or green June beetles. The katydid and June beetle are herbivores whereas the dragonfly is a predator on flying insects. So quite a community of creatures populate the pollinator field and provide a real oasis of life.

Fly Syrphid yellow jacket mimic on heliopsis

So despite the fact that the planting of a pollinator field provides only an ephemeral burst of flowers over a short period of years, it is a significant source of food and cover for a wide variety of creatures and is a valuable tool in maintaining biodiversity within the pasture/hayfield habitat.

Bill Dunson
Galax, VA and Englewood, FL

Aaron Floyd 9/16/15 Aaron Floyd 9/16/15

Educational resource planted last Fall shows us life!

On September 15th we started a second Young Explorers Club with seventeen pumped up 10-13 year olds. The program kicked off our 2015-16 Galax After School Enrichment Program. We will be meeting with the kids two days a week and taking one extended Saturday field trip each month during the school year. The Young Explorers will earn a Junior Naturalist Certificate over the course of 2015-16.

For our first session the group gathered to discuss official club items in the classroom. After talking about the array of subjects we will be studying and what it means to be a naturalist, we honed in on insects in preparation for an October 17th field trip to the Hokie BugFest in Blacksburg. Our first club activity was to visit the butterfly garden on school grounds to do some maintenance and field investigation.

Last fall, BRDC, led by Sarah Osborne, planted a brand new butterfly garden on the grounds of the Galax High School as part of the Fall 2014 Middle School Enrichment Program. The results a year later are astounding! The garden is lush with life and the sharp eyes of the students quickly discovered a Monarch butterfly, then a caterpillar, then a bigger caterpillar, then three chrysalises and a caterpillar forming it's chrysalis! They were ecstatic to say they least!

In the short time available the students weeded out the crab grass, collected seeds to be planted in the spring and found an array of insects in the garden. We are looking forward to studying the garden in detail during the coming weeks. The students will also be building a club insect collection to be entered into the insect collection contest at the Hokie BugFest.

What a fantastic resource for young scientists to explore life! Every school needs a pollinator garden.

Bill Dunson 6/17/10 Bill Dunson 6/17/10

A mistake leads to an unexpected insight

How often do we just muddle along without much clarity of thought? I found myself in this situation when I was returning from a very early breeding bird survey on one of Virginia's highest peaks (Whitetop) and noticed some interesting plants. One of these (see photo) was a mountain wood sorrel, which I mistakenly identified as a Spring beauty, since the flowers are similar (see photo). I realized that the leaves of wood sorrel are similar to those of a shamrock and thus completely unlike a Spring beauty, but discarded this thought. Later, several folks pointed out the error of my ways and I reflected on the similarity of these two flowers which are in completely separate families.

Generally when two plants or animals are quite similar there is a common origin and a close relationship. That is not the case here since wood sorrels (Oxalis) are in a distinctly different family from Spring beauty (Claytonia) which is a relative of purslane and portulaca. So why do the flowers look so similar? The most obvious explanation is that they have converged in structure and color due to similar function. So what do these flowers do? They propagate the species by producing seeds, usually by attracting pollinators. Since the color and form of flowers is closely matched to the type of pollinators, perhaps these two flowers are designed to attract similar insect pollinators? Aside from the color, one of the most distinctive aspects of these two flowers is the pattern of lines radiating from the center. What could be the purpose of such lines? The usual explanation is that they are guides to direct insects to the center of the flower. For example look at the third photo taken in our garden of a native bee (sweat or mason) in the flower of an yellow evening primrose which also has the radiating lines. Some geraniums also show distinct lines in the flowers. So this pattern is not uncommon in unrelated plants.

So why do insects need some help in finding the center of flowers? Flowers sometimes also have a dark throat patch (the so-called nectar guide) to provide an additional cue. Insects primarily use their compound eyes that may have good color vision (plus UV), but their acuity is not as good as ours. Thus they may depend on simple patterns and odor for flower recognition and orientation. It is apparent that flowers find it important to give their pollinators as much help as possible in locating the sources of nectar and pollen. This must facilitate the fertilization of flowers and thus speed the evolution of such adaptations in multiple lines of descent.

So let's resolve to pay a bit more attention out there and enjoy even more the fabulous array of diverse forms of flowers and attempt to fathom what their purposes are.

Bill Dunson

Galax, VA & Englewood, FL

Bill Dunson 12/29/09 Bill Dunson 12/29/09

Snake plant flowers

It is hard to believe that anyone has not at some time had snake plants (Sansevieria) in their family households. The ability of this interesting but strange plant to survive almost any treatment made it popular around the world as a house plant. Unfortunately in warmer areas such as Florida they ended up planted outside and have caused considerable problems since they are highly invasive, especially in shaded forest locations where native plants are crowded out by the snake plant. Removing them is problematic since the roots break into small pieces and generate many new plants.

I have fought a running battle with snake plants in our Florida yard since a former owner got them started. So I always considered them a big pest with no redeeming qualities. However I have now recognized that the regular Winter-time blooms of these plants are actually quite interesting from an ecological perspective (see photo). A spike of white tubular flowers emits a powerful fragrance and is actually quite beautiful, if you can get past the bad-boy image of this species. I am always interested in predicting what might pollinate specific flowers, based on flower color, shape and smell. I found out that this plant originated most likely from Western Africa but have not yet found out what pollinates it in its native habitat. However the white tubular flowers with a strong odor indicate pollination by a night-flying moth with a long tongue, possibly a sphinx/hawk moth whose larvae are often called horn worms.

I did find one article that determined that the primary sugar in the nectar of the common snake plant is sucrose, and predicted that this in conjunction with the flower structure would attract mainly sphinx moths. Note also that the authors found extra-floral sources of nectar and surmised these might satisfy creatures such as ants that might otherwise steal the flower nectar and limit the plant's ability to reproduce:

http://aob.oxfordjournals.org/cgi/content/abstract/58/4/541

So look around you with a renewed interest in plants and animals that you might have dismissed as unworthy of notice, and you may find unsuspected beauty and interest among the "bad boys" of the natural world.

Bill DunsonEnglewood,

FL & Galax, VA