Category Archives: Butterflies and Moths

Bees & Pollinators, Birds, Butterflies and Moths, Light

Like Moths to a Flame – Rethinking Outdoor Lighting in Your Garden

April 24, 2023 peterboroughmastergardeners Leave a comment

by Emma Murphy, Master Gardener

A few weeks ago, the incomparable Lorraine Johnson spoke at my local horticultural society. She summarized four key actions gardeners could do to help our pollinators, and the last one stuck out for me — reduce/reconsider outdoor lighting (see her full list of actions at the bottom of the blog).

I thought, what does outdoor lighting around my house or garden have to do with pollinators? I know that the presence of lighting (or even more importantly, light frequency) is disruptive for migrating birds and nesting sea turtles, but for pollinators in my garden?

However, what I’ve learned in my research is that artificial lighting at night (aka ALAN) poses a hazard to nocturnal pollinators and prevents proper navigation, reproduction, and their ability to find food.

This really cool graphic (from Kenilworth Park and Aquatic Gardens in Washington DC) shows some examples of day and night pollinators.

Why is it a problem?

Use of ALAN has rapidly spread around the globe over the past few decades. This 2021 Nature Communications journal article states increasing evidence that ALAN adversely affects the behaviour, physiology, and survival of animals and plants, ultimately leading to a significant decline in their abundance and diversity.

This 2020 Biological Conservation journal article says that although habitat loss, pesticide use, invasive species, climate change all play a role in insect decline, ALAN is another important—but often overlooked—bringer of the “insect apocalypse”.

A Nature journal article back in 2017 also sounded the alarm, showing that in ALAN plant–pollinator communities, nocturnal visits to plants were reduced by 62% compared to dark areas.

This UK Royal Horticultural Society article lists some of the effects of ALAN, not just on pollinators but all wildlife:

Nocturnal insects (including many moths) who navigate using natural light sources (like the moon) are disoriented by ALAN (although research is now indicating that ALAN disrupts circadian rhythms in both nocturnal and diurnal animals).
Security lights appear to temporarily blind some animals and may even attract them (for example, frogs – I have seen this in my backyard near my pond).
Birds are disturbed from sleep by sudden lighting and can begin singing before dawn (robins especially seem sensitive to light). Birds that start migration flights at night can become disoriented.
In ALAN areas, shorter periods of nighttime darkness means less time for foraging/hunting for crepuscular (dawn/dusk) or nocturnal species.
ALAN is thought to be partly to blame for the decline of fireflies/glow worms; the females emit low, greenish light to attract mates and even low level ‘skyglow’ from distant light sources such as floodlit playing fields or towns will lessen their breeding success.

The type (frequency) of light seems to affect species differently. For example, research indicates that LEDs seem to attract more moths and flies, but fewer beetles than sodium lamps. And LEDs with cool white light (blue end of the spectrum) attract more insects than warm white ones. As a general rule insects are more sensitive or attracted to short-wavelength (UV, blue and green) than long-wavelength (orange, red and infra-red) light.

So what can gardeners do?

While ALAN has become a trendy part of our outdoor living spaces, consider whether you really need it, or modify it to minimize its impact. In my back garden I definitely need some path lighting for visiting guests, but I make sure it’s shielded lighting that is on a motion sensor so it’s only on for a short time. The International Dark-Sky Association has some great information on keeping our skies dark, including using shielded light fixtures that minimize glare, light trespass, and skyglow.

Besides, a garden can be just as magical a place enjoyed in moonlight or simply with the aid of a flashlight! And if you minimize ALAN you might just see more fireflies/glow worms in your garden, like I do (hint: having a pond or water feature also attracts them).

Want More Information?

Moths do the pollinator night shift – and they work harder than daytime insects

Fatal attraction: how street lights prevent moths from pollinating

The Darkness Manifesto: On Light Pollution, Night Ecology, and the Ancient Rhythms that Sustain Life by Johan Eklöf (on my to read list)

Bees & Pollinators, Birds, Butterflies and Moths, Houseplants, Information, Native Plants, Perennials, Shrubs & Trees, Slugs and Bugs, Technology

Google Lens (free!) for all of your identification needs

September 12, 2022 peterboroughmastergardeners Leave a comment

By Mary-Jane Pilgrim, Master Gardener

If you’re outside enjoying the fresh air, and happen across a flower or bird or insect and you’re not sure what you’re looking at, a new feature from Google can help you out.

Google Lens lets you search what you see. Using a photo, your camera or almost any image, Lens helps you discover visually similar images and related content, gathering results from all over the internet.

All you need to do is: On your phone, open the Google app and in the search bar, tap Google Lens. Point your camera at the flower to identify the plant. Swipe up to learn about the discovery.

On Android, Google Lens is likely already built right in — open the Google App or Google Photos app. Tap Discover or tap the Google Lens icon.

On Apple, Google Lens is part of the Google app — a separate app from using Google on Chrome, Firefox or Safari. Go to the App Store and download/install Google as a unique app if you haven’t already done so.

When you open the Google App, you’ll see a screen like this with the Lens icon. It’s your window to discovery!

Last week, I went for a long walk and checked out a lot of the volunteer trees and plants along the rural roadway. Sometimes I wanted to verify an item I thought I already knew, but more often I wanted to determine the name of a common but name-unknown item. Google Lens scored on both fronts. Now if only I could remember all of those names!

If you have a bug infestation, use Google Lens to identify the bug if you can get it to sit still long enough!

There’s plenty more you can do with Google Lens, too, including pulling the contact information from business cards, identifying unusual foods and almost anything else. It can also translate words on the screen into other languages, and read them back to you.

The ability of the app to actually CORRECTLY identify plants and bugs is pretty decent, and will get better over time. It helps to allow Google to use location services, so that it’s not searching through the entire rain forest to determine the name of the plant in your neighbourhood. You can also allow Lens access to your photos, so that you can identify items you’ve already taken pictures of.

Best of all, it’s free and will always be free. Try it!

Bees & Pollinators, Butterflies and Moths, Insects, Slugs and Bugs

Holes in Leaves

August 1, 2022 peterboroughmastergardeners Leave a comment

By Christine Freeburn, Master Gardener

Several years ago I heard a wonderful talk by Martin Galloway on “Holes in Leaves.” His philosophy was that you can never totally eradicate pests from your gardens, so you should enjoy the beautiful lacing they do to your leaves. At the time, I was skeptical about how I could love holes in leaves and the pests that put them there. However as a Master Gardener, I now understand his perspective and I do try for a balance using safe methods to control pests. Integrated Pest Management (IPM) is a practice where pests are controlled using environmentally safe and economically sound values. Biological controls like BTK or parasitic nematodes can be used. Barriers such as diatomaceous earth, wood ashes or sticky boards are mechanical control methods as well as hand picking. Cultural methods include plant nutrition, sanitation, planting pest resistant varieties and plant rotation (in the case of vegetables).

Although we don’t want bad bugs in our garden, we do want the beneficial bugs that are predators and parasites. These include dragonflies and damselflies, lady bugs, lacewings, spiders, wasps and some types of flies.

Aphids or plant lice are one of the most common pests to attack your plants. They are tiny soft bodied creatures that can be black, red or green in colour. They suck the sap from your leaves, and leave a sticky substance behind. You will often see them in a long line on your stems. Red aphids are common on garden phlox. You can use an insecticidal soap for aphids. Or use a blast of hose water to knock them off your plants.

Beetles are hard bodied insects that are generally easy to find on your plants. There are many types and they are often named after their plant of choice, like scarlet lily beetle. The most effective method for controlling beetles is hand picking. Look for the striped cucumber beetle inside the blossoms. When handpicking, place a hand under where the beetle is to catch it as they tend to jump when you touch them.

Caterpillars are another garden pest that are easily spotted. In spring you may find your Hydrangea arborescens has closed, puckered leaves which are holding the common leaftier. You can gently open the leaf and remove and destroy the caterpillar inside or pluck of the entire leaf and squish.

Slugs and snails are sometimes difficult to find as they like dark damp places and feed at night. But you will know you have them when they are munching on your hosta leaves. Check out Gardens Plus for Dawn’s formula for slugs.

As we enter the dog days of summer, we are all battling voracious bugs eating our beautiful flowers and vegetables. The healthier your plants are, the less they will suffer from a deluge of bad bugs. That is why it is important that you give your plants the water and nutrients they need to be their best. Good soil health and good fertilizing methods will give you healthier plants.

Remember that anything you apply to your plants to kill those pests can also hurt pollinators and will be on the vegetables and fruit that you ingest.

To make your garden less inviting to pests

plant the right plant in the right spot to keep it happy and not stressed
do not overcrowd plants which encourages dampness and pests
diversity in your garden will help with pest control – if there are a variety of plants, specific pests will not take over
keep nitrogen levels moderate as many pests like aphids thrive on plants with high levels of N.
Remove garden litter; if pests are present as they can overwinter there.

My favourite method of hand picking beetles and slugs and hosing down aphids is no cost and gets you out into your gardens….where you can enjoy your own “Holes in Leaves.”

For more information on garden pests go to https://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/pests-and-problems.aspx

or try https://cdn.dal.ca/content/dam/dalhousie/pdf/agriculture/ExtendedLearning/gardenbox/Managing%20Vegetable%20Pests_Garden%20Box_Online.pdf

Bees & Pollinators, Birds, Butterflies and Moths, Garden Design, Information, Insects, Native Plants, Perennials, Shrubs & Trees, Sun Gardening, Vegetable Gardening

The Joy of Sharing our Gardens

July 11, 2022 peterboroughmastergardeners 5 Comments

Reflections after a Garden Tour

by Emma Murphy, Master Gardener

It’s been a tough few years for all of us because of COVID-19, but I had time to reflect this weekend on why it’s been hard for me as a gardener. While it’s been wonderful to have our gardens as an oasis and source of comfort during the pandemic, I realized that other than a few close friends, no one had seen all the work (and the results) that my husband Grant and I had achieved over that time.

So it was with great anticipation that we looked forward to our Lakefield garden being featured on a garden tour organized as a fundraiser to celebrate 60 years of the Lakefield Horticultural Society.

While we spent a few very crazy days trying to put the final touches on our garden (my husband decided he would build a beautiful pergola [awesome] a week before the event [not so awesome] so plants had to be moved into pots and then back into the beds just a few days before) — sorry I digress — everything was perfect on the day — the weather was spectacular, we placed the last bits of mulch to cover a few empty patches and we looked forward to welcoming our guests.

As the first people arrived (I think our first visitor was a man on a bicycle!) I began to realize how much I had missed the joy of sharing our gardens with others. And as the day progressed, it was wonderful to hear other people’s perceptions — for some it was inspiring, for some a bit overwhelming (we have a 3/4 acre property in a small village), for some they loved that we had plants they had never seen before (not your typical garden). Everyone seemed to leave with a smile on their face, which made our day.

Grant created numerous raised beds over the past few years — at my request — and we’ve had great success with them. We also purchased a “COVID present” for ourselves — a long wished-for greenhouse to extend our gardening season, and it’s been put to good use.

We’ve spent time over the past few years planting more native plants as I learn more about the benefits of creating habitat as well as having an aesthetically pleasing garden. Hey, it’s not all about me!! Doug Tallamy’s book is a great start to understanding the benefits we can provide in our humble gardens to the greater ecosystem.

There is definitely a balance — we’re aiming for a 50/50 balance of native/non-native — because I love my daylilies and peonies and don’t want to give them up (they give me pleasure), but I also love the hundreds of pollinators (bees, butterflies, wasps etc.) that flock to my Common Boneset (Eupatorium perfoliatum), Pearly Everlasting (Anaphalis margaritacea), Cup Plant (Silphium perfoliatum), and Cardinal Flower (Lobelia cardinalis) because I am choosing to plant native plants.

Boneset (white) and Cardinal Flower (red)

Last winter I grew some native (and non-native) plants using the Winter Sowing technique (because most native plant seed requires winter/cold stratification) and it was a great success (with some lessons learned – but that’s another blog).

Grant set up a Plant Sale area for the garden tour and people were able to buy plants that they saw in the garden (although alas, I did not take any cuttings on my amazing orange Butterfly Weed – a type of milkweed – which really caught everyone’s attention).

Over the day I saw many gardening friends I hadn’t seen in several years, and made all sorts of new friends. It felt like my community was coming together — like we were reconnecting after a long time apart in a beautiful place. And I realized that gardening is both a solitary and a very social activity. We even got featured in the local newspaper.

We raised funds to support our local horticultural society, we got back to feeling ‘a bit normal’, and most importantly we got to reconnect with people over a common passion — the love of gardening.

I hope that all of you will find opportunities to reconnect with people this summer and share your gardens and plants and trade stories about attracting pollinators etc. with others. It’s a feeling like no other. #happygardening

Our lovely rudbeckia and greenhouse in the background.

Bees & Pollinators, Birds, Butterflies and Moths, Climate Change, Native Plants, Perennials, Planting

A Few of My Favourite Native Plants

May 16, 2022 peterboroughmastergardeners 2 Comments

by Emma Murphy, Master Gardener

I’ve been gardening for more than 25 years and, like many of you, thrill at the opportunity to discover new plants for my gardens. Over the past few years these have been mostly native plants, as I learn about all the benefits that they bring – here’s just a few examples of why native wildflowers, grasses, shrubs and trees do so much more than just add beauty to the landscape:

They support birds, pollinators and wildlife – native gardens attract birds and butterflies and provide habitat and food for native pollinators
They increase biodiversity – native plants increase garden health and resilience, and help contribute to a broader effect to nurture and sustain living landscapes
They’re tough and low maintenance – because they’re adapted to grow in their native range, locally native plants tend to thrive with little to no care and conserve one of our most precious resources – water
They help you save money AND create a healthier environment for people – native plants don’t require expensive fertilizers and chemicals, or toxic pesticides and herbicides
They help with climate change – no lawn mower costs or exhaust! and long lived native trees help store carbon dioxide
They make gardening easier – if you select the right native plants for your garden, you don’t have to modify or amend your soil

I’m just going to share three favourite native plants in my garden, with hopes that you may consider them for yours.

Culver’s Root (Veronicastrum Virginicum)

Culver’s Root offers a strong upright, architectural accent to any perennial garden that attracts attention from both people and pollinators!! It can reach heights of 5 feet if it’s happy (although mine hasn’t achieved that yet) and the spikes of white flowers open from the bottom up in mid-summer. It has finely toothed leaves that are lanceolate and occur in a whorl of 3 to 8 leaflets. The inflorescence has several wand-like flowering spikes that resemble an elegant candelabra.

Culver’s Root grows in zones 3-8, in full sun to part shade but it does like moist, well-drained soil. The seeds are so tiny that they should be directly sown on the soil surface in fall or in the spring – I’ve tried winter sowing some this year so we’ll see how that goes.

The plant really has no other synonyms; apparently the name was derived from a Dr. Coulvert, a late 17th to early 18th century pioneer physician who found laxative properties in the plant. More information here.

Cardinal Flower (Lobelia cardinalis)

Who doesn’t love bright red flowers in the garden? For those who say native plants can’t be showy I give you this amazing example to disprove that theory. Named for its scarlet red flowers, its tubular flowers are a magnet and important nectar source for hummingbirds and swallowtail butterflies.

Like Culver’s Root the flowering spikes open from the bottom to top and bloom for several weeks. They grow best in moist, rich soils in full sun to partial shade.

I’ve only had my plants for two seasons but I understand that the parent plants will not persist after a few years, so it’s important to either let it go to seed (so it reseeds naturally) or collect seed – this is another plant where I am trying out winter sowing (native plants are a great choice for this propagation method). While many sites will tell you it needs a really moist site mine have done fine, although I do keep the plants well watered in drier times. More information here.

Green Headed Coneflower (Rudbeckia laciniata)

Also commonly called Cut Leaved (or Cut Leaf) Coneflower, this is the straight species, not to be confused with the double cultivar many of us have in our rural gardens (often called the Outhouse Plant – or Rudbeckia laciniata “Golden Glow”).

Not a small plant (it grows 4 to 5 feet tall in my garden), it clumps and spread by rhizomes so only one to consider if you have the space! Its bright yellow, daisy-like drooping flowers with green centre disks (which can be about 3 inches across) bloom later in the summer season. It prefers moist soil, but grows well in average, medium, well-drained soil in full sun to part shade. In nature it is often found in woods, meadows, streambanks, and roadside ditches.

The Cherokee natives call this plant Sochan and the spring basal leaves are a traditional Cherokee food. Butterflies are attracted to nectar from the blooms and songbirds, especially American Goldfinches, eat the seed in the fall. It is moderately deer resistant. More information here.

So I hope you’ll take the opportunity to seek out native plants to add to your garden, finding ones that are native to your region and appropriate to your conditions. Happy Gardening!!

Bees & Pollinators, Birds, Butterflies and Moths, Children, Dreams, Garden Design, Health, Insects, Perennials, Planting, Propagation, Seeds, Shrubs & Trees, Soil, Vegetable Gardening

Why Do We Garden?

March 21, 2022 peterboroughmastergardeners 2 Comments

by Emma Murphy, Master Gardener

“To plant a garden is to believe in tomorrow.” Audrey Hepburn

If you’re like me, you love to garden. Time in my garden provides me with joy on so many levels — emotional, physical, social, creative — and connects me with the outdoors and the environment. And while the COVID-19 pandemic has turned our lives upside down, one of the silver linings is that we’ve seen a renewed interest in gardening and its benefits, whether you’re working in a large garden or a few containers on your balcony. So I thought I would explore some of the top reasons I think we garden.

Physical and Emotional Health

Gardening is physical. As a low to medium impact exercise that requires both strength and stretching, you’ll see increased muscle strength and cardiovascular fitness over time, as well as improved sleep and diet (if you grow your own produce). On the emotional side, gardening reduces stress, anxiety, and depression and improves self esteem.

It’s good for the mind — gardening calms me down and helps me be more patient with myself and those I interact with on a daily basis. It gives me time to contemplate as I go about my tasks, up to my elbows in soil. Even weeding is cathartic, pulling out those little terrors by the root!

Just visiting gardens helps to calm the mind, bringing a sense of contentment and tranquility from looking at beautiful landscapes, flowers, or just colour and texture.

Building Relationships

While gardening can be a solo activity (some of my favourite moments are just by myself in my green oasis), it’s also a fabulous way to connect with people, whether they be family or strangers!

Teaching people how to nurture a living thing and to be responsible for a little bit of the environment is a lesson and gift we can share with others. Gardening knowledge is shared through generations — I love hearing about plants handed down from grandparents, or children working with their parents to grow seeds for the first time. It’s a great way to pass on critical life lessons — about patience as plants and vegetables grow, responsibility as they look after their care, and loss when flowers die at the end of a season.

Beyond family, gardening helps us connect with the broader community. Whether you plant too many tomatoes or zucchinis and end up giving them away to neighbours, or participate in a community garden plot, gardening can be a very social activity and a chance to learn from, and share your bounty, with others.

Learning Life Values

Gardening teaches you important life values like patience, determination, caring, and hard work. It also makes you very humble as you realize that there is always something new to learn. You need to observe the seasons and the weather, and this puts you in contact with the natural world. I love that I can get dirty and do this very physical activity, working with seeds and plants and seeing growth in all I do.

Growing Your Own Food

Gardening provides benefits for your wallet, your nutrition, and reduces your environmental footprint. By growing your own food (either from seeds or small plants), your food is automatically more sustainable simply because you are doing it onsite or in a community garden. If you control the ‘inputs’ and do it well, you can save a lot of money.

But ultimately there is nothing more rewarding than planting and maintaining your own vegetable garden and harvesting (and sharing) your results. And we all know how much better homegrown produce tastes versus conventional produce at the grocery store. If you have too much produce, then you can just share the love with others!

Connecting With Nature

I think this is one of the best reasons why people have a garden — the sunshine on your face, hands in the dirt, and feeling connected to nature. The garden is so much more than just plants and flowers — it’s the birds, the bugs, the bees, the spiders, the snakes and all the small mammals. I feel like I am establishing a little ecosystem in my own garden and that I am trying to give back for all the benefits that I receive.

Working in the garden also gives you that sense of wonder, accomplishment, and reward. To grow plants is to give life. It keeps you busy but reminds you to be one with the earth. To see the results of something growing from seed to six feet tall is just incredible.

Exploring Creativity

I find gardening to be an incredibly creative activity. Finding the right plant for the right spot, mixing colours, and making sure there is interest for every season — these are real challenges. I’ve spent much of the past few years learning about new plants to consider in my garden, especially natives.

Helping The Environment

Finally, gardening is so important for our planet. Even though we create our gardens (so they are human made) they do represent natural environments, with trees and shrubs and plants that are all taking in carbon and releasing oxygen. The plant roots stabilize the soil and filter water, and the plants themselves support our pollinators.

We live in a symbiotic relationship with our gardens. We give back by planting and maintaining them, but we receive so much more from them than we give.

Why do you garden?

Books, Butterflies and Moths, Garden Cleanup, Insects, Planting, Websites

Lending Insects a Helping Hand in our Gardens

August 9, 2021 peterboroughmastergardeners Leave a comment

By Laura Gardner, Master Gardener in Training

When some of us think of insects, it is common for them to be thought of in a negative light. Some of our earliest childhood memories include being stung, bitten, or just plain scared by the sight of them. I can remember running screaming from an outhouse at a provincial park when I was about five years old. What was so scary? It was the sight of a Yellow Garden Spider (Argiope aurantia) hanging in its web in the stall. Fortunately, the experience didn’t make me fear or dislike spiders and as a gardener I know how beneficial they are to have around. While some insects certainly do deserve our scorn— invasive species such as the LDD moth (Lymantria dispar dispar); Emerald Ash Borer (Agrilus planipennis); Japanese Beetle (Popillia japonica), etc.—by and large, the majority of insects are harmless and beneficial. Not long ago, I saw a couple—perhaps grandparents, out for a walk with their grandson. One of them was urging the young boy to stomp on an ant on the pavement, calling out “Get it! Get it!” It was disheartening to see. It is experiences like this that call for a shift in our thinking about insects.

Bumblebee (Bombus sp.) on False Sunflower (Heliopsis helianthoides)

I recently got a sneak preview of a book by British entomologist Dave Goulson called Silent Earth: Averting the Insect Apocalypse (Harper Collins). It is to be published this Fall (September 2021). The copy I reviewed was an e-book proof and so page numbers referred to here may change in the final published copy. Goulson’s work is primarily focused on bumblebees and as the founder of the Bumblebee Conservation Trust in the UK, he is dedicated to reversing the decline of them. He is also known for his work that was instrumental in influencing the European Union’s decision to ban neonicotinoids in 2013. Goulson wrote this book in an effort to bring more public attention to the recent and rapid decline of global insect populations—which are critical for our planet’s survival. He also explores the chief causes of insect declines such as habitat fragmentation, industrial farming practices, pesticides, climate change, and non-native insect diseases (p. 71) and provides suggestions for readers that can help support insects—especially gardeners.

Bumblebee (Bombus sp.) on Sweet Joe Pye Weed (Eutrochium purpureum)

Here are a few highlights from the book:

Goulson refers to a phenomenon called “Shifting Baseline Syndrome” where humans tend to only see their current world as “normal” and are unable to detect changes over time. Humans also tend to have something called “personal amnesia” in which they downplay the extent of change (p. 64-65). With these points in mind, it is no wonder that most people would not know that insect populations have recently declined by as much as 75% (p. 50) and that there have been parallel declines in populations of insectivorous birds (p. 58). One bird that I remember as a child that I haven’t seen since is the Eastern Meadowlark (Sturnella magna). This species is one of those that depends on insects in its diet.

One concern that the author has is the level of human awareness of the existence of the natural world. It is important to learn the names of plants and animals—otherwise they cease to exist. If they don’t exist, their importance can’t be recognized. Astonishingly, in 2007, some of the words eliminated from the Oxford Junior Dictionary included words such as acorn, fern, moss, clover, kingfisher, otter, among others (p. 225).

87% of all plant species require pollination in order to flower, produce fruit/seeds, and ensure perpetuation of the species. This includes 75% of all agricultural crops (p. 26). Most of this is performed by insects and a large part is performed by those other than bees—flies, ants, beetles, wasps, moths and butterflies. A world without insects means that we would need to subsist mainly on cereal crops as these can be wind-pollinated. I can’t imagine going without fruits such as strawberries, apples, cherries, raspberries, and even my morning coffee (p. 26).

Insects are not only important pollinators, but they assist in the development of healthy soils. Not only do they help to aerate soil, they are valuable decomposers of organic matter—participating in a process along with bacteria that help make nutrients more available to plants (p. 29, 31). As biological control agents, predatory insects such as Lady Bugs (Coccinellidae spp.), Lacewings (Chrysopidae spp.), Ground Beetles (Carabidae spp.), Wasps (Vespidae spp.), etc., can help us reduce the need for pesticides.

Blue Mud Dauber (Chalybion californicum) on Swamp Milkweed (Syriaca incarnata)

What can we do to help?

Despite the current state, Goulson is optimistic that insect declines can be stabilized or reversed because they are generally good at reproducing—we just need to support them better (p. 216). Here are some ideas:

Learn how to identify the difference between harmful and beneficial insects. The majority (95%) are the latter.
Reduce or avoid the use of pesticides and give beneficial predatory insects a chance to take care of the problem first (p. 277). Even so-called organic treatments such as diatomaceous earth, BTK, horticultural oils, etc. need thoughtful consideration before use as they can harm harmful as well as beneficial insects.
Learn how to differentiate between irreversible and cosmetic damage in your plants. Accept that plants are meant to be food sources for insects and some imperfections and damage is ok. Give up growing ornamental plants that are persistently defoliated by certain insects (e.g. Asiatic Lilies).
Incorporate a wide range of native plants that flower throughout the season in your garden to attract beneficial insects. One of the best late flowering perennials is New England Aster (Symphyotrychum novae-angliae). It provides a valued food source for migrating Monarch butterflies. Some of the best food sources for insects are early flowering trees such as Serviceberry (Amelanchier spp.), Maple (Acer spp.), and Crabapple (Malus spp.).
When using mulch in flower beds, leave some soil exposed so that ground nesting bees can have easy access. Some solitary wasps such as Mud Daubers (Sphecidae spp.) also need easy access to bare soil in order to glean material to build their nests.
Reduce lawn and use the space for more plants. Reduce mowing of the lawn that exists. Allow a corner of your garden to “grow wild” and “get messy.” (p. 277).
Choose native plants over “nativars.” A nativar is a cultivated variation of a native plant. Some are supportive of pollinators but many are sterile or lack pollen and therefore are unable to provide food. The ones that are most likely to be the least supportive will have features such as double blooms, different leaf colours, etc. Reduce planting of ornamental annuals like Petunias, Begonias, Pansies, etc. because of their tendency to have no pollen or nectar (p. 233). That being said, some of these plants can still be enjoyed.
Choose a range of plants that support the broadest number of insect species. While Milkweeds (Asclepias spp.) are in the limelight as being supportive of Monarch Butterflies (Danaus plexippus), compared to some other plants, they only support 12 Butterfly and Moth species (Tallamy, Bringing Nature Home). Goldenrods (Solidago spp) support 115 different species. Some, like Canada Goldenrod (Solidago canadensis) can be aggressive in small gardens but there are more restrained types such as Blue-Stemmed Goldenrod (Solidago caesia), and Zigzag Goldenrod (Solidago flexicaulis).
Avoid aggressive fall and spring clean-up of leaves and hollow, dead stems. Doug Tallamy describes the practice of waiting 7-10 consecutive days of 10 degree C. temperatures for insects to emerge as myth as many insects emerge at different periods throughout the season. For example, Io (Automeris io) and Luna Moth (Actius luna) emerge around mid May (Tallamy, Leaf Litter: Love it and Leave it).
Recognize that commercially produced “Bee Hotels” can become populated by non-native bees such as European Orchard Bee (Osmia cornuta), Horned-Face Bee (Osmia cornifrons), and Blue Mason Bee (Osmia coerulescens) as well as native bees (p. 135). If used, periodically clean them so as to reduce mites and fungi that can be harmful to the bees.
Reconsider taking up beekeeping as a hobby. The European Honey Bee (Apis mellifera) threatens native bees because they take the lion’s share of available plant pollen (p. 139). It is also not a good strategy to rely on one species for pollination in case something happens to that species (p. 33).
Raise awareness and share your knowledge with family and friends. You can convince others that insects need our help if they realize they themselves will be personally impacted by their decline (p. 216).

Selected Resources

Holm, Heather. Pollinators of Native Plants: Attract, Observe and Identify Pollinators and Beneficial Insects with Native Plants (Pollination Press, 2014).

Tallamy, Doug. Bringing Nature Home: How you can Sustain Wildlife with Native Plants (Timber Press, 2009).

Tallamy, Doug. Leaf Litter: Love it and Leave it. April 2021. Online: https://tinyurl.com/4jphhnbc

Walliser, Jessica. Attracting Beneficial Bugs to your Garden: a Natural Approach to Pest Control (Timber Press, 2013).

Xerces Society for Invertebrate Conservation. Visit https://xerces.org/publications to view and download a wide range of factsheets and other guidance documents concerning beneficial insects, native plant lists, pesticides, habitat construction, and more.

Monarch Butterfly Caterpillar (Danaus plexippus) on Swamp Milkweed (Syriaca incarnata)

Bees & Pollinators, Butterflies and Moths, Insects

Hosting butterflies

August 2, 2021 peterboroughmastergardeners Leave a comment

By Lois Scott, Master Gardener

Life has been busy in my garden lately, and I don’t necessarily mean me! My husband Ray and I have been enjoying the array of pollinators that are busy in the garden. What has us particularly excited is seeing species of butterflies that we have not noticed in the garden before. For example, Ray identified a Large Wood Nymph butterfly (Cercyonis pegala) that I noticed feeding on heliotrope. Although it spent a lot of time feeding on the heliotrope this is not a host plant for this particular butterfly. According to The Audubon Society Field Guide to North American Butterflies host plants for the Large Wood Nymph are native grasses such as Little Bluestem (Schizachyrium scoparium).

So, what exactly is a host plant and why is it important? Host plants are plants that an organism, (larva) lives on and lives off of. A well-known example is the Monarch butterfly. It will feed on a number of nectar plants including milkweed but Monarch larvae only feed on milkweed (Asclepias) species. Milkweeds are the Monarch’s only host plant. Important pollinators like butterflies and moths need host plants on which to lay their eggs and enable the subsequent larvae to have a food source. The photo below shows Little Bluestem (Schizachyrium scoparium) in the foreground is a host plant while the Mexican Sunflower (Tithonia rotundifolia) behind it is a nectar plant.

Little Bluestem grass and Mexican Sunflower provide host and nectar sources (respectively).

According to the Ottawa Field-Naturalists’ Club (OFNC) butterflies need plants that are good sources of nectar, sun, shelter from the wind, and host plants on which to lay their eggs. Yes, larvae eat the leaves on the host plant but typically do not cause serious damage. Along with providing a list of plants for nectar sources this site gives a list of host plants for larvae for specific butterflies. Many of the host plants are trees including birches, willows, dogwoods, oaks, hops, cherries and hackberries to name just a few. Other host plants include native wildflowers and grasses.

The OFNC site provides more details on providing the most desirable conditions for butterflies and makes the point that to restore butterfly populations we need to recreate suitable habitats for them. This is another list of valuable host plants.

If you are interested in attracting more butterflies consider adding some of these valuable host plants to your garden. Many of these plants can be sourced at Peterborough’s Ecology Park where you can also get expert advice on suitable plants for your garden conditions.