It’s June – where are all the native bees?

A hike in a Phoenix nature preserve today revealed very little in bloom, and consequently few native bees or butterflies.

Most of the Sonoran Desert native bees have just one generation per year, so, unlike the non-native Western Honeybee, many native bees will only be active and visible during the Spring or Summer wildflower blooms.

During my hike today, the only flowers I observed were on White Ratany, which was being visited by a bee species whose flower visits were so brief it would take an AI to get a photo,

White Ratany

California Barrel Cactus, whose flowers weren’t yet opened,

California Barrel Cactus

and Coues’ Senna, which had mainly gone to seed but still managed to produce flowers.

Coues’ Senna

Native bees feed on pollen and nectar as well as flower oils for germicidal and bonding properties. Many are solitary, meaning they don’t belong to social hives, and make their nests and brood by burrowing into the ground or using tunnels in wood made by wood-boring beetles.

In my yard in North Phoenix, the native bees seem to have disappeared for a week or so before I wrote this post, so I figured they were gone for the season, even though there are plenty of Desert Marigolds, Zinnias, Sunflowers, Rush Milkweeds, Lantana and Desert Willows in bloom.

But then they reappeared. If native bees for the most part have only one generation per season, how can they be gone and then come back?

So I reached out to Elliott, our resident native bee contributor, and he had a bit of light to shed on the situation:

There’s a few things. Bet hedging, where not every egg hatches every year in case of droughts. Seasonality of host plants for sure and what else in the area is providing food that might be attracting them away from your yard. Pesticides and lack of suitable nesting habitat is a big urban problem. Also, there’s usually small bees going undetected by human observers due to their size and speed.

Elliott Gordon

In addition, I reached out to my friends in the Pollinator Gardening in the Southwest facebook group and asked what they are seeing in their yards.

The larger longhorn bees are active this month on Gaillardia pulchella flowers; Svastra obliqua and many Melissodes males and a few females of both species. The female Valley Carpenter Bees are still out every day. Lots of Triepeolus Cuckoo bees and Anthophora californica bees. The Svastra duplocincta time their June emerging with the neighbor’s Barrel Cactus flowering, which it has already and the males and females are now out and about in large numbers. Lots of activity in my Arizona garden even with the 111 degrees we had today. The number of Megachile bees are lower than usual this year, however. Wondering if the various cuckoo bees that showed up this year in greater numbers than previous were responsible.

Kim Neubauer, Phoenix West Side

I see gulf fritillary butterflies daily and occasionally giant swallowtails and queens. Lots of native bees, mainly sweat bees, leaf cutters, carpenter bees, and another that I haven’t identified.

MM, Central/Midtown Phoenix

A few Queens at the Mistflowers, weekly visit of Giant Swallowtails to the orange tree, a few Skippers at zinnias and Mexican Evening Primrose. Plus 3-4 species of native bees on the sunflowers, desert lavender, globe mallows, coreopsis, fairy duster & Superstition mallow.

MH, NE Phoenix

Phoenix temps 110. Not seeing too many 🦋 besides gulf fritillaries. Bees and wasp come around splashes in the pool to try and get water.

VC, Phoenix

A lot. At my fountain plants.

SBC, Phoenix

Plenty! My garden is full of yellow flowers and pollinators, but the wild spaces are brown and dry from lack of rain. I saw yard bee species 82 last weekend and yard moth/butterfly 100 last night.

Elliott Gordon, Albuquerque

You can learn more about native bees at:

Meet the Author: Dr. Shaun McCoshum

Shaun McCoshum is the author of two books on pollinators and gardening – Gardening for Wildlife in the arid south west regions and Inviting Pollinators and Other Wildlife Into Your Garden – available on Amazon.com. He received a master’s degree in botany from Miami University (Ohio) and a doctorate from Oklahoma State University in zoology.

Hunt’s Bumblebee on Rabbitbrush

What is your background? How did you first get interested in bees and gardening for wildlife?

From a young age I had been gardening and using permaculture techniques before I even learned the term. My maternal grandparents lived a block away, and they both were in their late teens when the Great Depression hit. When I was six, both my parents lost their jobs and we became really poor, and very food insecure, so my grandmother got to work. She had me helping her do work to grow fruits and vegetables in her garden. Most people did not realize how much of the yard was growing food for us. In back we had more organized food gardens. I continued gardening throughout my younger years; then in high school, I started working as a landscaper and helping friends and family install similar gardens, all the while being aware that areas needed to be cared for to support wildlife to help control pests and pollinate flowers.

These experiences simply paved the way for me to study biology at Humboldt State University and get a botany minor. Between my master’s and PhD, I worked in conservation, which really helped me grasp ecological niches, microhabitats, and looking at areas from the animal’s perspective. During my PhD, I focused on pollinator communities and worked on side projects with monarch butterflies. I went on to do my post-doctoral work at Cornell University working on bee communities in the Mojave Desert and their vegetation community associations, as well as large-scale solar farm impacts to those communities. After my post-doc, I worked as the preserve manager for Westchester Land Trust in New York, then moved onto consulting and permitting, which I do now, while still collecting data and publishing research and books.

Gray hairstreak and bee fly on Cowpen daisy

Why did you decide to write a gardening book?

The short answer is because a few people told me I should. With my background in native bees, monarch butterflies, ecology, and conservation, I end up doing a lot of public speaking. I also enjoy reading gardening articles. Between these two things, I kept answering questions that were clearly based on incomplete or incorrect information, most of it printed in gardening articles and even coming from some conservation groups. My first book focused only on the arid regions of North America to help clarify some of the misinformation that is spread around. [Read my review of his first book here.]

Who is your intended audience? Anyone who has an interest in urban ecology, wildlife conservation, or gardening.

Ashmeadiella bee and flower beetle on native bindweed

What piece of advice would you give to people wanting to start a pollinator garden?

Pollinator gardens should be viewed in context of their surrounding landscape and provide shelter, in addition to native plants for target species. For example, in densely populated urban areas where lawns are abundant and habitat is lacking, a small pollinator garden will not be accessible to bee species that have been driven away, nor will it support many bees overall. Therefore, providing an abundance of flowers for smaller generalist bees and butterfly host plants will be more useful than flowers that support just a few bee species or do not host any butterflies. Resources for nesting bees and pupating butterflies would have to be selected based on the region, but a few logs with holes drilled in always helps. Conversely in areas where there are more wild, plant-filled areas, pollinator gardens that use native plants uncommon in the area will help local pollinator communities because species dependent on those plants are likely still nearby. Viewing a garden from the landscape context is also helpful when trying to attract other wildlife like birds, toads, or even lizards. 

Bordered patch caterpillar on sunflower

What kind of research did you do for the book?

So much. In addition to the literal decades of studying, reading scientific literature, doing conservation work, new data collection, and gardening – I started compiling data for topics and reading various forums, print articles, and reviewing resources gardeners might be using. The most important research I did for this book was probably gathering the data for plant and bee associations, and their current ranges. For the bee species profiles I also reviewed a lot of literature searching to find what substrates each species nested in. I put these aspects together to provide specific information on what a pollinator garden that would “save the bees” really looks like, going beyond articles with native plant lists that benefit honeybees, not native bees.

For the articles that do talk about “bee hotels,” they inadvertently prioritize a nesting behavior used by about 30% of bees and rarely address proper size or care of those structures. There are very few articles that address ground nesting bees, which my new book covers; but promoting ground nesting bees is showing up more and more on online platforms, which is good to see.

Checkered skipper on paperflower

Were there any surprise findings? What did you learn in the process?

The most surprising thing I found was how much we simply do not know about pollinators. I had been somewhat aware of the lack of data, but it wasn’t until I was trying to compile information that I really grasped the lack of data. For example, there are over 4,000 species of native bees in the continental United States, but researchers have described the nests of less than 500 species. Frustratingly, many of those descriptions do not characterize soil texture or document entrance solar exposure, both of which are important to nesting bees. So, in this book, soil diversity and structure are discussed to help cover different possibilities. Sandy soils are used more often by nesting bees than any other type of soil.

It was also shocking to see, and this is in the book too, that more than 50% of counties in the contiguous United States have fewer than five native bee species digitized as of 2020. We simply have not done a thorough survey. The data for which bee species feed on which plants are also lacking. Even in this book I could only report plant associations, and I explain this does not mean the bees will feed on those plants. When bee researchers collect bees, they often do not include notes on if the bees were collecting pollen, feeding on nectar, collecting oils, plant parts, or simply sitting on the plant. Most likely, the bees were feeding in one way or another, but the data simply do not exist for most bee species yet. Luckily, community science platforms like iNaturalist are improving our knowledge, but it is difficult to help gardeners choose plants for their gardens when we aren’t sure which bee species might be in the area.

Male longhorn bee (Melissodes) on Spiny goldenweed

All pictures by Shaun M. McCoshum, some rights reserved (CC BY-NC). Some answers edited for clarity and length. My thanks to Shaun for agreeing to be interviewed. – Elliott

Book Review: Gardening for Wildlife in the arid south west regions

Thank you for reading my review of “A short introduction to Gardening for Wildlife in the arid south west regions” by Dr. Shaun McCoshum. If you are interested, the book is available for purchase on Amazon.com

With 29 full-size pages, this book is lightweight, but not light on content. It is specifically aimed at arid environments, which is refreshing given the lush, yet unrealistic, gardens portrayed on many websites. Even if we long for shady lawns, it’s irresponsible to maintain high water use landscaping in Arizona and New Mexico.

Native desert landscapes can serve as inspiration for our own gardens, and they are the best way to support native wildlife

The book is essentially split into 5 sections: brainstorming/planning for your garden, reptiles, bees, butterflies, and birds. I would characterize this book as in between a do-it-yourself guide and a reference manual – it has explicit instructions for planning your space, lizard sunning spots, bee hotel, and water feature, but also leaves it open to the reader in terms of selecting plants and doing further research.

The ligated furrow bee, Halictus ligatus, and Spiny goldenweed, Xanthisma spinulosum are discussed in this book

One of the strengths of the book is the knowledge Dr. McCoshum brings to the bee section. I love the discussion of ground-nesting bees, which are the majority of native bees in the world (and especially the desert southwest). The book addresses crucial elements of bee habitat in addition to the plants that they forage. Regarding the plant lists, you may want a wildflower book or Internet browser handy, as the names are largely in Latin.

Bottom line, I recommend this book. I think it will be most useful to people starting out, renovating part of a yard, or wanting to attract more of a specific kind of wildlife, like bees or lizards. It would make a great, not so subtle, gift to a neighbor who’s still hanging onto their lawn. You can hear more from Dr. McCoshum in this Youtube recording of a talk he gave for NMSU: https://youtu.be/Q6v6CLOui6c

Glamorous Moths #5 – Penstemonia

The way that gardeners feel about moths and butterflies is often quite different, despite how closely related they are. We are happy to grow milkweed to attract Monarchs and allow the caterpillars to devour whole plants. Weed is in the name milkweed, so I think we value the plant more for its role in the Monarch’s life cycle. On the other hand, who ever heard of growing corn to attract Helicoverpa zea or tomatoes to encourage Manduca sexta?

Perhaps the most despised moth is the peach tree borer, which “bring major harm to important fruit-crop trees, destroying the tree’s vascular system through boring and girdling while inducing plant pathogens to invade the weakened tree” (Source). That’s terrible, right? How dare those selfish moths cripple our precious fruit trees?

Without further ado, I would like to introduce the Penstemon clearwing, also known as the Beardtongue borer.

Penstemonia clarkei, Clarke’s Penstemon clearwing, seen in Los Alamos, New Mexico

Penstemonia is a genus of moths in western North America (presumably including northern Mexico) in the family Sessiidae (clearwing moths). [Quick sidenote: Hemaris clearwing moths are in the hawk moth family, Sphingidae.]

Clearwing moths often resemble wasps and bees in coloration and marking. They have elongate wings, often transparent owing to the lack of scales. Most of the larvae are borers in the limbs, trunks, bark, or roots of trees, shrubs, herbs and vines (like the infamous peach tree borer). Some bore in galls on woody or herbaceous plants. Majority of adults take nectar. [Source: bugguide.net]

What about our Penstemon clearwing? 

There are at least 5 species of Penstemonia in North America. Larval feeding is probably limited to Penstemon or closely related plant species in Cheloneae. (I’ve discussed Penstemon plants on the blog before: https://pollinatorweb.com/meet-the-plants-more-beardtongues/). The larva will be found within a stem [or roots] at crown level and damage appears as a wilting or dieback of individual stems. Pupation is probably in the soil at the base of plants, but there is no description of them. [Source: Colorado State University Extension (colostate.edu)]

I have a feeling that populations of Penstemonia moths will start to increase and spread as more gardeners grow native, drought tolerant beardtongue plants. I hope you will welcome these pollinators into your yards with open arms.

What are those white “eggs” all over my Cascalote?

Also described a “salt deposits” or “sugary specs” and followed by yellowing leaves, black mold spots and defoliation. What’s going on?

Freysuila dugesii (Jumping Plant Lice)
Generally host-specific, and appearing in late spring

Sometimes called jumping plant lice, psyllid feed on a variety of plants. Both adults and nymphs feed by piercing the leaf surface to extract cell sap, and excrete “honeydew”, a sweet sticky residue that may attract ants or mold. When I first saw these white deposits, they appeared to be insect eggs, but others have described them as a crystal-like sugar deposit.

You may be familiar with the term honeydew as related to aphid infestations, a sweet excretion loved by ants. In fact, it’s believed that ants protect and cultivate aphids in order to harvest the honeydew. Psyllids are part of a group called Sternorrhyncha that includes aphids, scale insects and whiteflies.

Leafhopper Assassin Bug feeding on Mesquite Psyllid

Controlling Psyllids

Although a psyllid infestation is rarely lethal for the tree, it obviously takes its toll in the form of leaf loss, virus infections and, well, reduced garden aesthetics. Here are some measures you can take to control the infestation:

  • Spray the leaves daily with water to knock off honeydew and psyllids. If performed diligently this can minimize the infestation, but psyllids can fly away and come back.
  • Spray the complete tree with Neem oil. Psyllids hide in between branches and nymphs like the back side of leaves, so complete coverage is best. Neem oil is practically non-toxic to birds, mammals, bees and plants. Neem oil is slightly toxic to fish and other aquatic organisms. Azadirachtin, a component of neem oil, is moderately toxic to fish and other aquatic animals. It is important to remember that insects must eat the treated plant to be killed. Therefore, bees and other pollinators are not likely to be harmed.
  • Biologic control with parasites and predators. Important natural enemies of psyllids include lady beetleslacewing larvae, predaceous bugs, Leafhopper Assassin bugs, and tiny parasitic wasps.

For more information:

Pollinator Web: Arizona Bark Scorpion

Observing the cast of characters that comprise the pollinator web ecosystem in the low desert in Phoenix Arizona.

Although this scorpion does not seek to attack humans, it will sting if threatened, especially if its young are threatened. The bark scorpion is able to climb vertical surfaces that are sufficiently rough, and can enter a dwelling through cracks as small as 1/16″. They are nocturnal and can be found under rocks, wood piles or bark, as well as on rock walls or in trees.

Arizona Bark Scorpion (Centruroides sculpturatus)

The Arizona bark scorpion is the most venomous species in North America; potent enough to cause severe symptoms, such as severe pain, numbness and vomiting in adults.

But of course, the Arizona bark scorpion plays a critical role in the ecosystem, as both predator and prey. They consume beetles, spiders, crickets, cockroaches, other insects and other scorpions. And they are a food source for pallid bats, birds (especially owls), reptiles, spiders, snakes, peccaries, rodents and other scorpions.

The pollinator web ecosystem is well balanced, and even characters that we may find scary have their place.

For more information:

The Lifecycle of Butterflies

A comparative look at a few southwest species

It’s early May in Phoenix and we’re starting to see lots of blues, and more and more Monarchs, Queens, Yellows, Whites and Skippers. But in my yard there has been an interesting lag the past couple of years – I’ll observe an early generation of butterflies in March/early April, then for a few weeks hardly any butterflies.

Is this cycle unique to my yard, or perhaps it’s related to the natural lifecycle of our butterflies? An early generation becomes active (or migrate in) in March, mate and lay eggs, then a few weeks later the next generation begin to show up in the yard. Let’s look at the lifecycles of some of our butterflies.

Gulf Fritillary

We had a mild winter this year and I’ve seen Gulf Fritillary caterpillars on the passion vine without stop. They are cold blooded though, so cold temps will slow down their metabolism.

Lifecycle: Egg to Adult in 4 – 5 Weeks
Egg stage – 4 to 8 days
Caterpillar – 2 to 3 weeks
Chrysalis – 5 to 10 days
Butterfly – 2 to 4 weeks

Monarch

The Monarchs develop from egg to adult in about 4 weeks:

  • Eggs hatch in about 4 days. Females lay one egg on a plant; in their lifetime they will lay 100-300 eggs.
  • Caterpillars go through five instars in about 14 days. When they first hatch, caterpillars eat the egg shell for nourishment. Similarly, they eat shed skin after every molt.
  • Chrysalis stage is about 14 days

The overwintering generation lives about eight months due to a biologic change that stops reproductive behavior during their migration south. The summer generations of the butterfly live only three to five weeks.

Great Purple Hairstreak

Great Purple Hairstreak

Lifecycle: Egg to adult in 5 – 8 weeks

  • Egg – 4 to 6 days
  • Caterpillar – 3 to 4 weeks 
  • Chrysalis – 10 to 20 days
  • Adult – 4 to 10 days

Painted Lady

Lifecycle: Egg to adult in 4 – 8 weeks

  • Egg – 4 to 14 days
  • Caterpillar – 2 to 4 weeks
  • Chrysalis – 7 to 14 days
  • Adult – 6 to 20 days

Milkweed Bugs: Friend or Foe?

What are those reddish-orange and black bugs crawling all over your milkweed, and are they harmful? Like many elements in an ecosystem, the answer fits into the gray zone.

Large Milkweed bugs (Oncopeltus fasciatus) and Small Milkweed bugs (Lygaeus kalmia) love your milkweeds as much as the Monarch and Queen butterflies, and they exist together as part of the natural ecosystem. Although their common names are similar, large and small milkweed bugs differ in more than size.

Large milkweed bugs (LMBs) are herbivorous – they feed on the leaves, stems, and seeds of milkweed using their long proboscis. In general this is not harmful to the milkweed plant, although if there is a large population boom, LMBs can stress the plant and cause misshapen seeds and lower seed production.

Large Milkweed Bug: note the black band across the wings and red face mask

Small Milkweed bugs (SMBs) are mostly herbivorous, but can occasionally be scavengers. These insects have been reported feeding on a wide variety of other insects, such as honey bees, monarch caterpillars and pupae, and dogbane beetles. While it may be disappointing to see monarch eggs, larvae or pupae preyed upon, this is all part of a vibrant milkweed ecosystem, and this predatory behavior is likely most common when their preferred food source is scarce.

Small Milkweed Bug: note the reddish-orange pattern forms an “X”

Milkweed bugs protect themselves by ingesting, then storing, cardiac glycosides from the milkweed, and as a result don’t have an issue with natural predators. The reddish-orange coloration is a warning to predators to stay away.

So should you be concerned about milkweed bugs in your garden? In general, no, they are part of the balanced ecosystem. However, if there is a large population boom, you may elect to reduce feeding pressure by culling some of the bugs, although this is a contentious subject 😉

Resources:

The potential consequences of ‘bee washing’ by Sheila R. Colla (2022)

Over recent decades, the plight of wild bees and other pollinators has gone from a niche area to one of the most mainstream environmental topics. Scientific research interest, capacity and consequently publications have grown tremendously in recent years, as has mainstream media coverage. The public has been engaged in a variety of ways to “save the bees” including through community science, policy consultation, planting of pollinator gardens and other widespread initiatives and campaigns … ‘Bee washing’, a term coined by MacIvor and Packer (2015), refers to items or actions claiming to support declining bee populations, and thus claiming to be pro-environment, without due diligence or scientific support … The crux of the matter is that when conservation actions are misplaced, as in the case with bee washing, they can actively harm populations meant to be conserved, waste limited resources (e.g. time, energy, money), misinform the public and/or de-legitimize scientific evidence.

Excerpts from Colla, S. R. (2022). The potential consequences of ‘bee washing’ on wild bee health and conservation.

To read more, visit https://doi.org/10.1016/j.ijppaw.2022.03.011 or the International Journal for Parasitology: Parasites and Wildlife, 18, 30–32

Native bumblebees may be threatened by “pathogen spillover” from managed species

In order to better protect wild bee health and biodiversity, conservation actions and policy will have to shift away from bee washing to more evidence-based, nuanced and precautionary approaches. Efforts should focus on reducing the reliance of systems on managed bees and reducing the impacts of managed bee use on wild bees. This will require policy which acknowledges and values the importance of wild bee health biodiversity for pollination services for crop plants and for resilience under climate change. Critical actions to protect wild bee health includes screening and monitoring of pathogens among commercial stock and in adjacent wild populations.

Excerpt from Colla, S. R. (2022). The potential consequences of ‘bee washing’ on wild bee health and conservation.

On Farming Metal From Plants and Intelligence Beyond Humans

Basking in our industrial and technological successes, humans have proudly flaunted their superiority over the natural world. But now the true cost of that hubris is coming to light – is it too late?

The answer will likely only make itself available in hindsight, but it’s not too late to learn.

In James Bridle’s Guardian article we a glimpse through the clouds at natural intelligence that has surrounded us, unnoticed until relatively recently. Read the story here.

There is so much intelligence on this planet other than ours. Realising that will be key to adapting to climate breakdown.

If we can farm metal from plants, what else can we learn from life on Earth? James Bridle

And how a slime mold, which is a creature somewhere between fungi and amoebae, can solve the “traveling salesman” problem faster than any supercomputer. The problem at hand: A salesman must visit n cities, going to each city only once, and then return to their starting point — what is the shortest possible route that they can take? Read the Science News article here.

And how cows, sheep and dogs appear to anticipate earthquakes better than any sensor or algorithm. Read the Scientific American article here.

And the octopus, whose distributed nervous system illustrates a different way of thinking. Read the Scientific American Mind article here.

Or how about spiders offloading cognitive tasks to their webs? Read the Quanta Magazine article here.

And not to leave out our often overlooked neighbors, how plants talk to each other through their roots. Read the Guardian article here.