A Brilliant Fall Banquet for Birds, Butterflies, and Bees

It’s that most glorious time of year in Maryland, peak autumn, a time of constant change where every day brings new explosions of color. Beyond leaf peeping along our morning commutes, changes large and small are detectable in exquisite detail, if we only pause to step out in nature to look, listen, and smell the fragrance of the season in the air. 

Right now, migratory birds are coming and going, shrubs are blooming and berrying, bees of all stripes are scrambling for the last drops of nectar as fall flowers fade. With some surprisingly low-cost, low-maintenance strategies, you can begin right away to transform your local landscape into a brilliant fall banquet for birds, bees, and butterflies.


At this time of year, wintering birds are beginning to arrive from the north, while some summer visitors linger to enjoy the bounty of fall. Dark-eyed Juncos (Junco hyemalis) are already returning from their northern breeding grounds. I spotted my first juncos of the season flitting about the raised garden beds on Halloween right outside of the Anne Arundel County Extension office. 

cabbage white butterfly
Cabbage White (Pieris rapae) butterflies were introduced to North America and are common across Maryland. Their larvae are considered to be crop pests. They typically reach the end of their adult life cycles toward late October. Photo: S. Small-Lorenz

On the same day, Cabbage White butterflies were still mobbing blooming New York asters in the brilliant noon sunlight on a day of record-breaking late October heat. The viburnum berries had already been plucked, possibly by the Northern Mockingbird (Mimus polyglottos) singing nearby, and its outermost foliage had turned a deep Cabernet red on a chillier night. I suspect that mockingbird has now staked out the American holly berries ripening nearby, as he seeks to maximize his energy intake before winter sets in.

Northern Mockingbird. Photo: Matt MacGillivray, CC BY 4.0

At Howard County Conservancy the day before, I noticed winterberry shrubs loaded with ripening berries, where another singing mockingbird steadfastly stood guard. Native honeysuckle (Lonicera sempervirens) is flowering and berrying simultaneously, gracing the trellis archway into the native plant garden, and the common witch-hazel (Hamamelis virginiana) is blooming, our only witch-hazel to bloom in the fall. 

Taking cues like this from nature can be an excellent strategy for planning our conservation landscaping for year-round color. Planting native berrying shrubs and evergreens not only extends our color palette, it provides natural sources of food and shelter for songbirds like Gray Catbirds (Dumetella carolinensis), Northern Mockingbirds, Cedar Waxwings (Bombycilla cedrorum), Eastern Bluebirds (Sialia sialis), Yellow-rumped Warblers (Setophaga coronata), Ruby-crowned Kinglets (Corthylio calendula), and thrushes as temperatures cool and extra energy is required to fuel up before, during and after migration. 

Depending on your specific location and site conditions, consider planting Maryland native berrying shrubs to enhance your fall bird banquet. These could include northern bayberry, maple leaf viburnum, red osier dogwood, native honeysuckle, black elderberry, native hollies (American, inkberry, and winterberry), huckleberries, and red chokeberry. 

Leaving fall seed heads standing into winter also provides resources for a whole array of seed-eating birds like sparrows and finches. Even as flowers begin to wilt and fade, they still provide essential nectar resources to native insects that are beneficial for their pollination and pest control services, not to mention as songbird prey. 

So if you are considering what you can do right now for nature and the environment in your own neighborhood, here are a few low- to no-cost fall strategies to get you started right away:

  1. Map out one or more locations that you would like to dedicate to a native shrub planting area. Make note of conditions (wet/dry, sunny/shady, soil type) so that you can select the right plants for your site when the time comes. It isn’t too late to plant native shrubs in most parts of Maryland, but if you choose to wait for spring, you can still start preparing the bed and browsing for fall-berrying shrubs now (see #5)! If you don’t know your soil type, this is the perfect time to do some home soil analysis. Observe where stormwater flows off of your property, and consider planting a mulched stormwater buffer using arborist wood chips and native plants to absorb rainwater which can both help reduce downstream flooding and improve water quality while beautifying your landscape. 
  1. Pledge to leave the leaves this fall. Raking a thick layer of leaves into your designated shrub planting bed will almost immediately start to create habitat, retain soil moisture, and build rich living soils. I call this “Raking by Design.” Think about this – who rakes the leaves in the forest? Towhees, sparrows, jays, bats, squirrels, deer, and many more wild residents…a reminder that leaf “litter” is an important habitat component for many creatures, and it puts essential nutrients back into the soil as the leaves decompose. If you’re concerned about leaves blowing around, it’s fairly easy to contain whole leaves with low garden border fencing, but it isn’t entirely necessary. Consider designating a portion of your yard a ‘no-rake’ wild zone, where you leave the leaves undisturbed, right where they fall.
leaves piled in a garden with a leave the leaves sign
Leave the leaves for healthy soil and habitat. Photo: S. Small-Lorenz
  1. Leave your native flowers standing well into winter, beyond peak bloom. Birds, bees, and butterflies will benefit from the stems and seed heads well into fall and early winter. 
  1. Use fall prunings, cuttings, logs or stumps to create shelter for overwintering birds, bees, and other wildlife. Recycling your “yard waste” is one of the easiest, low cost ways to start building healthy soil and creating habitat to benefit biodiversity in your local landscape. This can take the form of a brush pile, wood pile (situated well away from your home’s foundation), leaving a natural stump instead of stump-grinding, or building a simple “bug snug” like the one pictured here.
sticks piled into a pyramid to make a bug snug shelter for insects
A “bug snug” made with cut woody stems, seed heads, and leaves will provide a shelter for overwintering insects, stem-nesting bees, and birds. Photo: C. Carignan
  1. Browse options for native berrying shrubs to plant this fall or next spring that would be right for the conditions in your yard. While browsing native plant resources like Alliance for Chesapeake Bay’s Native Plant Center, also make note of whether the shrubs you choose are dioecious or not, meaning that you may need to consider planting female and male plants near one another in order for flowers to be fertilized and berries to form. Finding native plants locally right when you want them can be a bit challenging when getting started, so take some time to familiarize yourself with Maryland native plant material sources via Maryland Native Plant Society’s native plant shopping resources. 

Which of these low-cost, low-maintenance strategies are you planning to try to enhance your fall living landscape? Which berrying shrubs might you consider adding to your fall banquet? Leave us a comment below, and don’t forget to let us know which wild visitors are enjoying the fall feast in your neighborhood!

By Stacy Small-Lorenz, Agent, Residential Landscape Ecology, University of Maryland Extension. Read more posts by Stacy.

Fear of Insects: Understanding Our Fears to Help Conservation

Over the years, I have been involved in several initiatives that aim to summarize and translate our knowledge of insects, biodiversity, and some of the ecological services they provide, so that it can be understood by policymakers and the general public to inform decision-making and help ourselves and the living planet. The overwhelming take-home of these works is that insects (and biodiversity in general) are declining at a very fast speed, with very negative consequences on our ability to survive in a less diverse future world. When taking on these knowledge translation activities, however, there is one topic that keeps coming back: people are scared of insects (and wildlife, generally)! Then, how to promote the protection of something we’re scared of and disgusted by? In this blog post, I decided to embark on a mission: to help us understand our fears and recognize how they may be affecting our ability to protect the natural world, and what we can do to turn the wave on this to the benefit of all. Keep reading; I promise I will not shame or judge anybody 😉.

a beautiful collection of colorful beetles on display
Insects (only beetles shown in this picture) are the most diverse and abundant group of animals and play central roles in maintaining ecosystems. Photo: “Insects Unlocked” Project, University of Texas at Austin

The biodiversity crisis – a real problem with real consequences

There is now massive evidence that biodiversity is being lost. This is true for many groups of organisms, but here I want to focus on one in particular: insects. Why? Insects are the most diverse and abundant group of animals and, as such, they are deeply embedded in the running of the natural world. This diversity and abundance turn insects into sorts of ecosystem architects and janitors. They pollinate, feed on other organisms, degrade organic material and make nutrients available for others to consume, disperse seeds, and much more! Beyond the importance of all this to all organisms, these functions, in particular, are central to allowing us to produce food, maintain soil quality and balance, sustain rich ecosystems, and naturally control pests. Promoting insect protection, however, often faces a big challenge: low traction and low engagement, given the fear of insects.

Fear of insects – an encounter between humans and our natural world

Fear and disgust of insects is a very widespread feeling, especially in developed countries and urbanized societies. Although it is understood that the presence of fear or disgust usually develops as a protection system against potential dangers (and there are a few insects that we need to be wary of!), the extent to which fear of insects is present goes beyond what would be needed to properly protect us from a potential danger… And this is starting to have an impact on our ability (and willingness) to protect this important part of biodiversity. How does this work?

People have been studying fear of insects for a while and their findings are really interesting (you can read some neat reviews on this in Current Opinion in Insect Science and Science of the Total Environment). For example, researchers think that this extreme fear of insects may have evolved as a sort of “smoke alarm” (a loud but very non-specific type of alarm). In fact, there is reason to have respect for some insects, since some of them can lead to painful and potentially fatal bites/stings or can carry diseases. The presence of fear against those insects thus makes sense, because they lead to protecting our health. However, there is a balance to be found between responding to a real danger (e.g., hitting a hornet’s nest) or to an inexistent one (e.g., encountering a moth). Because the cost of responding to an inexistent danger is not super high in this case (like for a “smoke alarm”), then an extreme response to any insect can simply appear and spread through human populations. In this case, the only way to “tune” such an extreme response is to learn how to recognize harmful from non-harmful insects, something that many programs (including this blog! 😊) try to do.

Going back to biodiversity conservation, it is illuminating and empowering to realize that the simple action of learning can lead to increased conservation actions… learning when there is reason to stay away from insects or not leads to an appreciation of their huge diversity and more engagement in their protection. Some ways to do this involve using formal learning methods like courses, books, or guides, but also some more interactive ones, such as citizen science projects like iNaturalist or group-specific projects (e.g., the fireflies atlas).

a monarch butterfly
Rearing insects at home (like this monarch butterfly) can be a fun and learning-rich experience through which our appreciation for insects can grow and our fear decrease. Photo: Tim and Selena Middleton (CC)

Another way this fear develops is through social learning. As humans, we can learn through both direct experiences and social interactions. In fact, studies have shown that a large part of this establishment of fear or disgust in humans is learned through interpersonal interactions and not innate. For example, people have discovered that before age 5, most kids are not repelled by most insects or arthropods, and that the level of fear and disgust kids show is correlated with the fear their caretakers have of them. We see this a lot in our work. The Insect Zoo of our Department at the University of Maryland (UMD) is a very popular attraction at outreach events such as UMD’s open house event, Maryland Day. When participating in this event, we see time and time again how kids are not afraid of petting insects or other arthropods, while their parents are grunting and screaming in the background at the simple sight of one. Dealing with this learned fear is a bit trickier because it requires caretakers to become more aware of how they can imprint fear in kids. However, seeking to better understand and recognize insects and their potential (or not) of harm can help break this cycle. Rearing with kids insects like butterflies can be a great positive experience for all, and can happen in pretty much any house. Engaging in learning activities with kids, such as through insect summer camps (UMD has a super-fun Bug Camp!), is another way to restrict the establishment of this type of fear.

a women holds a spider in front of a boy at the insect petting zoo
Petting zoos and other exhibits that feature insects and other arthropods can be a great way to engage kids and adults in healthy and safe interactions with organisms they may fear. Photo: UMD Department of Entomology.

Finally, there is another way this fear may appear. We said above that this sort of fear is more common in urbanized societies. It is thought that a part of the fear may come from a lack of exposure to biodiversity. Under urbanization, there is indeed a removal of contact with natural environments, with people becoming less and less exposed to wildlife. When insects are seen (often in the house), the other two types of fears may pop up and join forces to, on the one hand, trigger repulsion or fear and, on the other, increase avoidance of natural spaces that could contain “bugs.” The good news is that even in cases when there are few natural spaces available close to home, there are indeed many ways people can be exposed and establish positive experiences with insects. Visiting exhibits where insects are featured is one of these ways. You can learn about many other ways in this cool article: Teaching About Insects in a World Afraid of Bugs.

By Anahí Espíndola, Associate Professor, Department of Entomology, University of Maryland, College Park. See more posts by Anahí.

Anahí also writes an Extension Blog in Spanish! Check it out here, 
extensionesp.umd.edu, and please share and spread the word to your Spanish-speaking friends and colleagues in Maryland. ¡Bienvenidos a Extensión en Español!

Termites and Carpenter Ants: How to Tell the Difference

termites
Eastern subterranean termites (Reticulitermes flavipes). Photo: Gary Alpert, Harvard University, Bugwood.org

Wood-damaging insect pests are a concern for anyone who lives in a structure made of wood. So it’s not surprising that we get several samples of insects for identification at our county offices.

Pests can damage wood by eating, excavating, or using it for their homes or galleries. Damage to foundational components can be especially alarming and expensive to fix.

Q. What are some physical differences between a carpenter ant and a termite that can be seen with the naked eye? 

  • Antennae – straight or elbowed?
    • Ants have elbowed antennae
    • Termites have straight antennae

  • Wing length – same length or is the front set longer?
    • Winged termites have wings that are much longer than the body and are of equal length
    • Winged ants have wings of different lengths
  • Pinched or narrow waist versus one long segment?
    • Ants have a narrow or pinched waist
    • Termites have bodies that are all the same width
a diagram comparing a termite and an ant
Comparing a termite (top) to an ant (bottom). Diagram courtesy of USDA Forest Service Archive, USDA Forest Service, Bugwood.org
a carpenter ant female
Black carpenter ant (Camponotus pennsylvanicus), winged queen. Photo: Jon Yuschock, Bugwood.org. Note the narrow or pinched “waist.”

Q. Is there a difference in the damage caused by carpenter ants and termites?

Yes. Both can compromise the structural integrity of a building but the actual damage is going to be different. Carpenter ants make galleries and excavate damp or moisture-compromised lumber to make their colonies. Termites eat the lumber and live in tunnels that they make. 

Q. What are the similarities between termites and carpenter ants?

  • Both are social insects that live in large complex colonies. 
  • Both carpenter ants and termites are attracted to moisture, so be sure to fix any drainage issues that would create a wet environment.

Q. Does landscape mulch lead to termites in your home?

The short answer is no; however, mulched areas may be more attractive to termite activity because of the increased moisture.

Here are some suggestions for protecting your home offered by the University of Kentucky.

  1. Try to prevent the wooden foundation from coming into direct contact with the soil. Also, prevent tree limbs from touching your roof, as this gives insects an easy pathway from the soil to your home. 
  2. Do not let moisture accumulate near the foundation. Divert drains and downspouts away from the foundation, as well as lawn sprinkler or other irrigation systems. 
  3. Reduce and eliminate excess moisture and humidity around the foundation of your home including both basements or crawl spaces. 
  4. Never store firewood or debris against foundations or inside the home. 
  5. Use mulch sparingly, especially up against the foundation. 

If you are looking for information on how to treat or prevent termite infestations, Mississippi State University Extension has all the details in its Methods of Termite Control. 

Remember that both these insects can be nuisance pests when they invade your home or other buildings; however, in nature, they are responsible for helping to break down stumps, fallen trees, and other debris. They also serve as a valuable protein source for birds and other small carnivores. So when possible, appreciate the value that they bring to your local ecosystem and food web.  

For all the details on termites and carpenter ants, visit the Home and Garden Information Center webpage. 

By Ashley Bodkins, Senior Agent Associate and Master Gardener Coordinator, Garrett County, Maryland. Read more posts by Ashley.


How to Protect Pollinators in the Fall

Did you know that how and when you cut back your perennials and tidy your landscape matters to pollinators?  

I just read a fact sheet from the Xerces Society that opened my eyes to more ways to help pollinators year-round, especially in the fall.   

I already make sure I have something blooming from April to frost, so pollen and nectar are always available. And I emphasize native plants that coevolved with pollinators to support them best.

But beyond flowers, there are many things we can do to provide shelter for nesting and overwintering pollinators. And we can start some of them in the fall. 

Pollinators and other insects shelter in stems and branches of trees, shrubs, and flowers. They also shelter in leaf litter, undisturbed or bare ground, dead wood, brush piles, and rock piles.  

Incorporating these features in your landscape – rather than cleaning them away – supports bees, butterflies, and other pollinators.   

So how can you make your garden more welcoming to pollinators this fall?

Start with the stems. Don’t cut back your perennials until late spring. Bees and other pollinators hibernate in the stems in winter. Only remove unhealthy plant stems to manage disease.  

But doesn’t that look a little unkempt? Yes, but messy is beautiful – and necessary for pollinators to survive and thrive.  

Master Gardener sign explaining why a messy garden is good for pollinators. Source: A. Cormany

The Master Gardeners and I believe this so strongly that signs in our teaching gardens say, “Excuse our mess, pollinators at rest,” to explain why we don’t cut back plants in the fall.

Next, leave some leaves. Most butterflies and moths use leaf litter to protect eggs, caterpillars, chrysalises, or adults over the winter. 

Wooly bear caterpillars tuck into leaf piles. Luna moths wrap their cocoons in leaves. Some butterflies lay eggs on fallen leaves. Queen bumble bees burrow into soil under leaves.  

A luna moth cocoon wrapped in leaves to wait out the winter.  
Photo:  M. Raupp

So pile some leaves around trees, shrubs, and perennials as a natural mulch. They will suppress weeds, hold moisture, and feed the soil. I chip some leaves but leave some whole.    

I often use leaf mulch in my vegetable garden, too. And when I had a larger landscape, I kept a 3-foot border of leaves against a stone wall to provide more shelter.   

Leaves aren’t litter: they’re habitat. Ideally, some leaves will become a permanent part of your landscape. Pick a corner, an edge, or a garden. I let leaves lie in a small woodland garden. 

But if you need to remove some of the leaves, try to leave them in place until mid-spring to give  overwintering pollinators a chance to emerge.  

This is really a glimpse of the many ways you can invite and support pollinators year-round. Learn more about Pollinator Gardens on the Home and Garden Information Center website.

Thanks for all you are doing to protect pollinators. It matters.  

By Annette Cormany, Principal Agent Associate and Master Gardener Coordinator, Washington County, University of Maryland Extension.

This article was previously published by Herald-Mail Media. Read more by Annette.

Scary Bugs (And Why You Shouldn’t Be Afraid)

Eek! It’s a bug!

I know most folks don’t like creepy-crawlies. Bugs aren’t their thing. Mine, yes, but this is what I do – help people deal with garden pests and protect good bugs.

Some good guys do look scary, like something out of a sci-fi movie with spikes and fangs and ridges and crazy colors.   

But looks aren’t everything. In most cases, these are good bugs – what we call beneficial insects – that help to control the few bad dudes in your garden.  

Let me introduce you to a few bug friends that aren’t beauties but do a beautiful job of controlling harmful pests.  

Assassin bugs get a bad rap simply because of their name. We’re talking James Bond, right?  

an assassin bug is a cloudy-gray color with a hump on its back
Scary-looking assassin bugs are efficient predators. Photo: Photo: Johnny N. Dell, Bugwood.org 

That’s a good thing. Assassin bugs are efficient predators, but boy, do they look scary. Battleship grey with spikes down their backs, they look like they’re wearing armor.  

But the battle is mostly one-sided. Insects that cross an assassin bug’s path likely will get skewered by its lance-like mouthpart and slurped dry.  

Stop shuddering. There’s an upside. 

Assassin bugs eat almost any bug, making them ecological balancers that keep insect populations in check. Plus, they enjoy snacking on Japanese beetles, the scourge of many a garden.

Cute and beneficial, the ladybug lies at the other end of the beauty spectrum. But as youngsters, ladybugs resemble tiny orange and black alligators which often get squished because they look like they are Up To No Good.  

a lady bug larva is black and organge and resembles a miniature alligator
Spiky ladybug larvae control aphids and other pests. Photo: Whitney Cranshaw, Colorado State University, Bugwood.org

Not true. These are good guys who consume even more aphids, spider mites, scales, and other baddies than adult ladybugs. In fact, one ladybug can eat over 5,000 aphids in its lifetime. 

Many juvenile insects look nothing like their more familiar adult counterparts. So stop before you squish or spray. Snap a photo or bring a sample to your local Extension office. Most likely it’s an ally you want to protect.  

You can find your Maryland Extension office on our website. Or reach out to the certified horticulturists at our Home & Garden Information Center for help. Send a photo or question to them at Ask Extension.

Wasps get a bad rap, too, with much swatting and shrieking and fear of The Stinger. Only females have those – they’re modified egg-laying organs – and they aren’t likely to use them unless threatened.  

But most wasps are beneficial, preying on bad bugs or laying their eggs on them to feed their young. Plus, they are pollinators, protecting 1 in 3 bites of food we eat. 

a wasp visiting a white-flowering plant
Scoliid wasps lay their eggs on Japanese beetle larva. Photo: Shanon Wolf

Spiders aren’t insects – they have 8 legs, not 6 – but they give many people the willies. But spiders also are beneficial, quietly and efficiently consuming many harmful insects.  

a black and yellow garden spider in its web
Argiope spiders provide free pest control in the garden. Photo: Heather Lawhead

Beauty isn’t everything. An army of not-so-lovely-but-useful insects are your allies in the garden, protecting your plants from the 1 in 10 bugs that are actually harmful. 

So think before you squish or spray. Get us a photo or sample. We’ll identify it and give you management tips that deal swiftly with bad bugs while protecting beneficial insects. 

By Annette Cormany, Principal Agent Associate and Master Gardener Coordinator, Washington County, University of Maryland Extension.

This article was previously published by Herald-Mail Media. Read more by Annette.

Support Our Insects at Night

We tend to think about protecting our insects when and where we see them. This is perhaps why we may have a higher propensity to think about protecting pollinators we can see flying around rather than organisms that live in the darkness of the soil or hidden in the leaf litter. In today’s post, I would like to bring some attention to other groups of insects we may tend to forget about but which we can also help protect: insects that are active at night.

Don’t insects sleep at night?

Although many insects are generally less active at night due to the lower temperatures and their inability to move when the temperatures drop below a certain threshold, many insects are adapted to being active at night. For example, if they are pollinators of nocturnal or dusk-flowering plants such as several moth species are, they will be active when darkness falls. Other insects are active at night as predators, or at certain times of the season looking for mates and egg-laying sites. For all these insects, the absence or reduced presence of light is important for allowing them to take on what they need to do to survive and/or reproduce. For this reason, the presence of artificial night lighting in our outdoor spaces, especially in the warmer periods of the season, can interfere with these insects, leading to potentially very negative effects.

How can outdoor night lighting affect nocturnal insects?

Insects can be perturbed in different ways through outdoor night lighting. One of them is its potential interference with their temporal rhythms. In fact, like most animals, insects use light-darkness and the presence of certain night sky cues (e.g., full moon) to regulate their developmental cycles and perceive the progression of the season. The presence of supplementary lights during the night hours can lead to altered developmental cycles, making them longer or mismatching those of organisms belonging to the same species. This can lead to the insects missing their optimal mating times, losing their ability to forage on specific plants, or properly preparing for the arrival of colder nights as the season progresses.

a string of lights is hanging over a a garden firepit area at night
The use of often non-essential lighting, such as light strings and other nocturnal accent lights in our spaces, can negatively affect the development, survival, and reproduction of many nocturnal insects. Photo: P. Danilyuk (CC)

Another issue that artificial nocturnal light can produce relates to the spatial disorientation of nocturnal insects. This can occur when insects are attracted to nocturnal light sources instead of moving towards their optimal habitat. This can lead to increased predation in those areas (the insects become more exposed to being seen), as well as their spending valuable energy by spending time in an inhospitable region. Further, disorientation can happen in a more indirect way by the light’s interference with the patterns present in the canopy. In fact, many insects have been shown to use the contrast pattern of the canopy and the sky to navigate and identify optimal habitats. The presence of nocturnal artificial lights can lead to the disappearance or a stark modification of that contrasting pattern, interfering with their ability to find their way in the ecosystem and decreasing their ability to find a proper habitat for their survival.

two fireflies light up at night
Some insects like fireflies use bioluminescence for inter-species recognition and mating. Photo: T. Ota (CC)

In some cases, the presence of nocturnal artificial light can interfere with mating and intraspecific recognition behaviors. Many groups of insects, such as fireflies and glow worms, use light cues to attract and recognize each other. In regions such as ours, where fireflies represent such an important part of our ecosystem, the use of outdoor nocturnal artificial lighting can interfere with the finding of mates and can potentially lead to much reduced abilities to reproduce and sustain populations.

What can we do to reduce this type of nocturnal pollution?

The obvious answer to this question is that if we want to reduce this type of pollution, our best bet is to turn off non-essential outdoor night lights, in particular during times of the year when insects are active. Doing this may actually save us some money, but also will allow us to support a higher diversity in our area, all while potentially letting us appreciate even more the nocturnal activity that may be present in our region. For example, doing this may make it easier to support fireflies and participate in their conservation, but can also support the reproduction of plant species that depend on nocturnal pollinators.

If leaving lights on is unavoidable, one should consider the intensity that is being used. Can the light be dimmed to a lower intensity? Could it be filtered to display a color that is less disruptive to insects? The Xerces Society has put together a really neat guide on this (Firefly-Friendly Lighting Practices – PDF), and I strongly encourage you to consult it if interested.

Finally, another way we can contribute to reducing unnecessary night lighting is by engaging in our communities. Initiatives such as DarkSky can help with this, both promoting best practices at the community level and engaging in conservation through community certification programs that are conservation-effective. You can learn more about these nocturnal conservation programs here.

By Anahí Espíndola, Associate Professor, Department of Entomology, University of Maryland, College Park. See more posts by Anahí.

Anahí also writes an Extension Blog in Spanish! Check it out here, 
extensionesp.umd.edu, and please share and spread the word to your Spanish-speaking friends and colleagues in Maryland. ¡Bienvenidos a Extensión en Español!

The Shared History of Wasps and Bees, And How Bees May Have Become Vegetarian

We may have all found ourselves in that situation in which we see an insect on a flower and we wonder whether it is a wasp or a bee, and we may have also seen people panic when they encounter a bee, thinking that it is indeed a wasp. Although the two groups are very distinct and there are several ways of telling them apart (check out this previous post to see how to do it), this difficulty is in part a signature of the shared evolutionary history that the two groups have. In today’s post, I want to tell you about the evolutionary origin of bees, how it is interwoven with that of wasps, and how evolutionary studies can help us understand and explain the diversity of our charismatic bees.

Evolutionary histories and the big family we are all part of

Before jumping into the main topic of this blog, please bear with me so I can give you a bit of context for what I’ll tell you, and so you can fully appreciate the power of the discoveries I will tell you about in just a second. One of the foundations of today’s biology and the way we understand life is that living organisms share a common ancestry and that evolutionary processes such as natural selection, mutations, dispersal, and random processes have led to the establishment of new lineages that can evolve into new species and new groups of organisms. What this means is that all the living organisms we know can be placed in a sort of genealogical tree, where more closely related species and groups appear placed on branches of the trees that are also closer to each other (we call these trees “phylogenies” or “phylogenetic trees”). Also, this means that if we were to take these trees, and we were to follow the evolutionary process “backward” (from the tips to the internal branches; that is, from the present into the past), we would be able to identify branching points, which represent the now extinct ancestors of species we know today.

a diagram of a family tree
A phylogeny can be compared to a genealogical tree we may want to build for our family. In this tree, the most closely related members of our family share recent ancestors (marked with diamonds), but are still connected with more distantly related members of the family with longer branches and other more ancient shared ancestors. In the same way, a phylogeny represents the relationships between species or groups of species, with branches connected by their shared ancestors. Image: University of Iowa

Although this may sound like a biological nerd moment of mine, I hope that you will appreciate the enormity of this principle. This simple concept indicates that each of us and all species that exist on the planet have shared ancestors at some point in our history. We are all related to each other, like a huge family… and as for all families, the study of our history can teach us fun and interesting things about who we are, helping us understand and explain things we observe today. Let me tell you what the study of these phylogenies has taught us about wasps and bees (and their shared history) and why this excuses us in part from not always being able to tell them apart 😉.

Bees and wasps, and the vegetarian wasp

As you may know, bees and wasps are both insects that belong to the order Hymenoptera. Despite the fact that people knew they were related but distinct from each other, it was not until relatively recently that people understood what that relationship was. In fact, because they share a lot of common traits, scientists were for a long time confused about what the most closely related group of Hymenoptera was for bees, wasps, and ants. Some years ago, with the development of new methods that allow for more detailed studies of phylogenies, researchers found strong evidence that ants are a group of organisms that is related but distinct from another group formed by bees and by a particular group of solitary and usually ground-nesting wasps called crabronids. Besides the taxonomic and purely conceptual importance of this discovery, what this meant biologically was on the one hand, that bees are evolutionarily extremely closely related to wasps, to the point that we could consider them “non-carnivorous wasps”. On the other hand, this discovery showed that all bees we know today would have evolved from a wasp-like ancestor that was solitary and ground-nesting, like the crabronids we know today.

a family tree of bees and wasps - showing evolutionary relationships
In 2017, Branstetter and collaborators used phylogenies to demonstrate that all bees and a group of wasps (crabronids) shared a common ancestry, indicating that bees can be considered a type of “vegetarian” wasp. In the figure, the position of the common ancestors is shown with arrows and stars. The main groups are labeled on the left. Image: modified from Branstetter et al., 2017

If you’re like me and find this fun, keep reading because it gets even more fun! 😊 So, after this discovery, the people who work on these topics wanted to know more. For example, can phylogenies tell us more about how the transition from a meat-based diet (wasps are carnivores) to a pollen-based one (bees feed mostly on pollen and nectar) could have happened? To investigate this, researchers ran a similar analysis, but this time considering a lot more species of both bees and crabronids. Constructing phylogenies using genetic information, they figured that when the evolutionary relationships of these groups were studied, it appeared that bees were the most closely related to a particular group of crabronids that is known to predate on thrips (a family called Ammoplanidae).

a closeup of a small black bee
Bees have been shown to be very closely related to a group of tiny wasps in the family Ammoplanidae which are known to hunt on thrips. Photo: CBG Photography Group (CC).

Besides confirming the discoveries of the previous study, this one provided a logical and interesting biological and ecological context for the transition from carnivory to pollinivory in bees. Thrips are a group of insects known to feed on plant materials, often found on flowers, where they feed on pollen. This new study proposed that a possible evolutionary opportunity may have appeared when a lineage of thrip-predating wasps evolved the ability to not only digest thrips meat but also the pollen they contained in their guts (!!). This transition could have set the evolutionary foundations to eventually transition to a diet fully based on pollen, which opened opportunities to the newly emerging lineage to feed on a new dietary resource not already in use by other wasps. If this is true, this transition would have provided an important evolutionary advantage (e.g., reduced competition for food), which would have led to the huge diversification of bees, leading to the extreme diversity we see today.

By Anahí Espíndola, Assistant Professor, Department of Entomology, University of Maryland, College Park. See more posts by Anahí.

Anahí also writes an Extension Blog in Spanish! Check it out here, 
extensionesp.umd.edu, and please share and spread the word to your Spanish-speaking friends and colleagues in Maryland. ¡Bienvenidos a Extensión en Español!