29 October 2010

Brown Garden Snail

4.5 years ago our yard was just a dirt pad. Since then, we've planted well over a hundred different native and arid adapted plants, trees, cacti, and succulents. As those plants have grown up we've watched the array of birds, insects, and other animals that visit our yard exponentially increase.

Brown Garden Snail
A week or so ago I discovered a new creature for our yard - a European Brown Garden Snail, - Helix aspersa.

Snails are very interesting creatures to watch.  They are most active at night and in damp conditions, yet this snail managed to find a place to live in our desert backyard.   They have an adaption that allows them to seal themselves off in their shell to minimize moisture loss.

The above snail was in fact "home" inside its shell, but after having been tormented by our daughter, I decided to leave it alone and simply get a photo of its shell.

26 October 2010

More Queen Caterpillars

The Queen Butterflies are continuing to reproduce prolifically in my backyard. They are particularly drawn to lay eggs on a Mexican Blood Flower (Asclepias currasavica) that is generally in full sun. This plant is barely hanging in there after getting eaten by numerous caterpillars for months.

The funny thing is we have three more Mexican Blood Flowers and three Pine-leaf Milkweeds in a less sunny location, and while the butterflies will feed on the nectar, they don't seem to lay eggs in that less sunny location.

The caterpillar below was one of 5 on the plant currently. I've documented the Queens of Maricopa previously - see the series Queen Butterfly, which shows adults, larvae, and chrysalis.
Queen Butterfly Caterpillar

22 October 2010

Mexican Amberwing

This year the hot weather seemed to hang on much longer than normal, with low 100's right up through the end of September. As tedious as the weather was, it allowed for some great late season dragonfly activity.

On an October 2 excursion to Boyce Thompson Arboretum, there were many species of dragonflies and damselflies active. None were more prolific than the beautiful Mexican Amberwings (Perithemis intensa), which numbers in the dozens, if not hundreds, at Ayer Lake.

Mexican Amberwing Dragonfly
Mexican Amberwing Dragonfly

Like butterflies, adult dragonflies only live for a couple of weeks, and often display worn and torn wings, as the one above shows.

In most of Arizona, the Mexican Amberwing is the prominent amberwing, especially in central Arizona around Phoenix.  The Eastern and Slough Amberwing is seen in the SE corner of AZ, though.

The photo below show another Mexican Amberwing, focused on the wings.  This provides an excellent look at the wings and vein structure.

Mexican Amberwing Dragonfly
Mexican Amberwing Wing Structure

For those interested in identifying dragonflies in the southwest, I have two book recommendations.  The first is a starter book that is small enough to be taken to the field.  Common Dragonflies of the Southwest, by Kathy Biggs.

The second is much more comprehensive, and highly recommended for any amateur or professional naturalist.  Dragonflies and Damselflies of the West, by Dennis Paulson

19 October 2010

Pipevine Swallowtail

Few butterflies rival the size and beauty of swallowtails, and the Pipevine Swallowtail (Battus philenor) is no exception. Common to much of the southern USA, it really stands out in the Arizona low deserts. When casual gardeners and hikers ask "what was that large black butterfly?", it is almost always the Pipevine Swallowtail.

Pipevine Swallowtail
Pipevine Swallowtail
In fact, here in the low deserts, really only the Black Swallowtail is somewhat similar, but easily distinguished by noticeable yellow banding that is absent on the Pipevine Swallowtail. This is not to mention larval food sources - Pipevine Swallowtails exclusively use pipevines, such as Dutchman's Pipe, while Black Swallowtails larval choices are in the parsley family. In fact, low desert gardeners who plant dill or parsley are likely to see the Black Swallowtail up close.

Back to the Pipevine Swallowtail - their larval food choice of pipevine is likely an evolutionary protection against predators. The noxious pipevines result in toxic larvae and adults, which over time predators learn to avoid. This is very similar to how to the Queen butterfly is thought to have adapted to choosing milkweeds.

15 October 2010

Turkey Vultures and Feather Mites

Turkey Vulture Spreading Wings
Turkey Vulture Spreading Wings
I recently heard and read about an interesting Turkey Vulture behavior - spreading wings in the sun as if they are drying them. I couldn't recall ever seeing this, but sure enough, I stumbled across it at Boyce Thompson in early October.

This behavior is very common in cormorants, seen frequently at bodies of water in Arizona.  But cormorants do this to dry their feathers are fishing and swimming in water.  Why would a Turkey Vulture do this?

The theory is that the Turkey Vultures are in fact drying and heating their feathers to ward off feather mites.  Feather mites are actually in themselves very interesting creatures - smart enough to move off of a feather that is about to be molted.  Note that it is also thought to be a means of general thermoregulation, but that doesn't explain why they'd be doing it on 90+ degree mornings in the desert.  Regardless, it was interesting to see this behavior in person. 

12 October 2010

Lowland Leopard Frog

As has been well publicized, around the world many frog species are in decline and are going extinct at an alarming rate (conservatively, 120 species have gone extinct since the 1980's).  In Arizona, this is also the unfortunate trend.  It is thought by many that frogs are more sensitive to climate change, and aren't able to relocate and adapt as quickly as some animals.  Weakened and decreased populations are then much more susceptible to diseases.

Lowland Leopard Frog
Lowland Leopard Frog
Given all of the pessimism around the future of frogs, it was nice to see what appeared to be a native Lowland Leopard Frog, Rana yavapaiensis, at Ayer Lake at Boyce Thompson Arboretum.  

Arizona is currently home to 15 frog species, including treefrogs and true frogs.  3 of those species are non-natives that were introduced to Arizona, and have established breeding populations.  Unfortunately, two of those introduced species present a real threat to native frogs, including thee leopard frogs.  The eastern USA native American Bullfrog is the largest threat.  Being a large frog that eats almost anything aquatic, leopard frogs are often on its dinner plate.  The introduced Rio Grande Leopard Frog also competes in the same habitats, and may be pushing the native Lowland Leopard Frog out.

So enjoy our frogs while you can.  Lets hope that conservation efforts can help mitigate the affects of disease, warming, and non-native introductions.

08 October 2010

Flame Skimmer Dragonfly

This Flame Skimmer (Libellula saturata) was seen in early September at San Pedro National Riparian Conservation Area near one of the ponds by San Pedro House. 

Flame Skimmer Dragonfly
Flame Skimmer
Flame skimmer rivals the Neon Skimmer in terms of over-the-top red/orange color, but the Neon, which is slightly larger, and a brighter red, still wins out.

The Flame Skimmer has a much larger range than the Neon, however, making it a more familiar sight.  Its covers most of the region of the Neon (except for eastern TX and central Oklahoma), and much more of the interior west.

05 October 2010

Digger Wasp

My early September trip to San Pedro yielded a number of interesting bird, insect, and mammal finds. This Digger Wasp (Scolia dubia) was one example of an insect that seemed to be common in San Pedro, but I've never noticed in my backyard.
Digger Wasp on Flower
Digger Wasp

The digger wasp, as one might expect, is known to burrow into soil, often near plants that it feeds on. It covers a wide range of the USA, with Arizona being about the western extent of the range.

01 October 2010

Grow Success in Desert Butterfly Gardening

Gulf Fritillary Butterfly
Gulf Fritillary - A Common Arizona Buttefly
Those new to the Desert Southwest are often surprised to learn that Arizona offers some of the greatest diversity in plant life, animal life, and insect life in the United States. In fact, only Texas rivals Arizona in terms of number of species that can be seen.

While I love to travel to interesting locations in Southern Arizona, it is also very satisfying to attract interesting insects and birds to my backyard. And what better way to take advantage of our inherent diversity than to try to attract some of it to our backyards! In fact, bird and butterfly gardening largely relies on native, drought tolerant plantings that serve to improve habitat and offset some of our homes impact on the natural land.

Today we're focusing on butterfly gardening. While butterfly gardening is relatively easy, I’ve found that many new to butterflies get discouraged at some point for a few reasons.

  1. They expect to have many large butterflies, like Monarchs and Swallowtails. The reality is that most butterflies and much smaller and much more inconspicuous.
  2. Gardeners tend to overlook larval food plants. As you’ll see below, some of the best attractants of butterflies are not flowers themselves, but rather the leaves.

This article is going to look at the most commonly recommended desert butterfly plants, some of which I’ll highlight as the “all-stars” of butterfly gardening. But first, a quick lesson in butterflies.

Butterfly Life Cycle

Butterflies begin their lives as small eggs, usually laid on a larval food plant that the specific butterfly prefers. Occasionally, eggs will be laid near a larval food plant, but the theme remains – adult female butterflies seek out a specific plant of family of plants for their eggs.

Eggs hatch and a caterpillar emerges. The caterpillars are often strikingly colored, and may be as much fun to observe as the butterflies themselves! Caterpillars are known as eating machines – they may even eat their egg shell along with the leaves of the larval food plant. Caterpillars may be tiny when they hatch, but as they grow they shed their exoskeleton – sometimes as many as 5 times. Caterpillars take a few weeks to grow to full size before they enter their next stage.  Caterpillars themselves are very interesting to observe, as I showed with these Queen caterpillars.

Caterpillars locate a place to pupate. This may be on the larval food plant, or nearby. The caterpillar sheds its skin and forms a chrysalis – a pupal case that some people call a cocoon. Note, however, that cocoons are unique to moths, not butterflies. The chrysalis can also be strikingly colored and very interesting – especially if viewed with close-focus binoculars or a magnifying glass.

Queen Butterfly Caterpillar or Pupa
After a few days to a couple of weeks, the adult butterfly emerges from the chrysalis. Most adults will only live a couple of weeks, but they make the most of their time and may mate multiple times.

Different butterfly species will be observed at different times of the year. Some butterflies are migratory (like Monarchs), while others simply prefer certain weather conditions. In some cases a given species will emerge and be most prevalent when their larval food plants are at their peak. In Arizona, a good backyard butterfly garden may attract 25 species of butterflies or more throughout the year. It is important to be observant. The tiniest of butterflies are easily overlooked, and many butterflies will be inactive during the majority of our hottest days.

Butterfly vs Moth

Generally speaking, if you see a butterfly or moth like creature flying in the daytime, it is a butterfly. Close inspection will reveal some other general differences. For example, butterfly’s antennae usually have a club-like knob on the ends. As mentioned above, butterfly caterpillars form a pupa, while moth caterpillars spin a silk cocoon. Since moths fly at night, they usually have a hairy body, thought to conserve heat. As with any generalization, there are exceptions.

Butterfly Shapes and Sizes

Western Pygmy Blue
It is highly recommended that the butterfly gardener purchase a butterfly guide, such as the Kaufman Field Guide to Butterflies of North America. These guides will provide insight into shapes, sizes, and behaviors of butterflies, and also provide range maps to give you an idea of what to expect. Good guides indicate which plants a species will prefer, and times of year they are most likely to be “in-flight” in adult stage.

That aside, be aware that many southwestern butterflies are very small – some as small as your smallest fingernail like the Western Pygmy Blue shown here. Despite the miniature size of some species, they can be quite colorful, especially when viewed with close-focus binoculars or a magnifying glass. However, we also get our share of very large butterflies as well, including Swallowtails, Queens, Gulf Fritillaries, and even an occasional Monarch. Note that some butterflies take on different postures. Skippers, for example, look much more moth-like than species traditionally identified as butterflies.

The Plants

I’ve become firmly convinced that larval food plants are as important, if not more important, than nectar plants. The larval plants attract adult butterflies to lay eggs. Further, some adult butterfly males “stake out” larval plants hoping to find a female. Not to mention that it is great fun to observe caterpillars and watch a butterfly life cycle.

Queen Butterfly Feeding on Nectar
Queen Feeding on Nectar
A good butterfly garden has a mix of larval food plants and nectar sources. In both cases, it is good to plant multiple plants of a given species. This is especially true of nectar sources, where a mass of a given plant may catch the attention of butterflies.  And note that not all flowers produce nectar, which is where the list below helps.

Your butterfly garden should insure most of the plants are in full sun, or close to full sun. Brightly lit flowers seem to be a strong attractant. However, it is also key to have some shade in and near your garden. Butterflies must regulate their temperatures, and need places to “cool off”.

Other Tips

Some butterflies like to “eat” salts, water, and other minerals from mud, as well. This is a common behavior sometimes called "puddling".  If you have micro-sprayers in your irrigation system, you may wish to make a small clearing where butterflies can come to visit the mud.  As an example, when I dump my daughters wading pool, within seconds I have American Snout butterflies that were "hiding" in my Desert Hackberry show themselves and soak up the water and minerals.

If possible, create two or more areas in your garden focused on butterflies. Given that the list of preferred plant species ranges from trees to groundcovers, and shrubs to grasses, it should be easy to create a yard full of butterfly attractants.

Lastly, use pesticides sparingly, if at all.

Larval Food Plants

Common Name Latin NameButterflies AttractedNotes

Baja Fairy Duster

Calliandra californica

Ceraunus Blue
Marine Blue


Bamboo Muhly

Muhlenbergia dumosa

Orange Skipperling


Black-eyed Susan

Rudbeckia hirta

Bordered Path

Common Sunflower

Helianthus annuus

Bordered Path
some cheekerspots

Excellent bird plant - finches love the seeds

Desert Hackberry

Celtis pallida

American Snout
Empress Leilia

All-star!  Also great bird planting.  Large shrub.

Desert Milkweed

Asclepias subulata


Desert Senna

Senna covesii

Cloudless Sulphur
Sleepy Orange



Anethum graveolens

Black Swallowtail

Parsley is said to work well, too.

Dutchman's Pipe

Aristotochia watsonii

Pipevine Swallowtail

Consider this one carefully - plants are very toxic and flowers smell odd.  Best for acreages and away from children.

Feather Tree

Lysiloma microphylla

Large Orange Sulphur


Fern Acacia

Acacia angustissima

Mexican Yellow
Several skippers



Phyla nodiflora

Phaon Crescent (rare)

ground cover

Golden Dyssodia (aka Golden Fleece)

Dyssodia pentachaeta

Dainty Sulphur



Eysenhardtia orthocarpa

Marine Blue
Southern Dogface

All-star!  Small tree can fit most landscapes

Longpod Senna

Senna leptocarpa

Cloudless Sulphur
Sleepy Orange


Mexican Blood Flower (aka Mexican Milkweed or Mexican Butterfly Weed)

Asclepias currasavica




Passion Flower

Passiflora species

Gulf Fritillary

All-Star!  Perhaps the strongest larval attractant

Pine-lead Milkweed

Asclepias linaria


Small shrub, provides nice texture

Pink Muhly Grass (aka Texas Muhly, Gulf Muhly)

Muhlenbergia capillaris

Western Pygmy Blue

All star!  grass

Side-Oats Grama

Bouteloua curtipendula

Orange Skipperling


Trailing Dalea

Dalea greggi

Southern Dogface

ground cover

Velvet Mesquite

Prosopis velutina

Leda Hairstreak


Nectar Plants

Common Name

Latin Name


Autumn Sage

Salvia greggi

Also a good hummingbird plant

Blackfoot Daisy

Melampodium leucanthum

White flowered nectar source; densely flowered groundocver/low perennial, but relatively short-lived - about 2 years.

Blue Cornflower (aka Bachelor Buttons)

Centaurea cyanus

May be larval food source for some species

Blue Mist

Eupatorium greggi


Butterfly Bush

Buddleia sp.

Can be higher water use

Chocolate Flower

Berlandiera lyrata

Has wonderful choclate fragrance


Echinacea Sp.

Many coneflower species are strong attractants, but require a bit more water than some of teh alternatives


Phyla nodiflora

Golden Dyssodia (aka Golden Fleece)

Dyssodia pentachaeta

All-star - it is also a  larval food source for Dainty Sulphur.


Lantana camara


Mexican Hat

Ratibida columnifera

Moss Verbena

Verbena pulchella

Spreading Fleabane

Erigeron divergens

Trailing Lantana

Lantana montevidensis

All-star! ground cover; blooms almost all year,
providing a nectar source when others are scarce


Verbena Goodingii


Lycium berlandieri

Note that there are other nectar sources and larval food plants that can be grown in the low deserts.  However, the goal of this article was to outline the "top" choices.  This means I selected the best attractants, and those that are relatively easy to grow.  I also have a slight slant towards native plants, which especially makes sense when considering larval food plants - we are attracting native butterflies, after all.  Lastly,
I've tried to avoid any invasive plants, though keep in mind that "invasiveness" can vary depending on your environment.

With all that in mind, a few others that didn't quite make the cut, but would function well supplementing the above include shasta daisies, Mexican sunflower, cosmos, snapdragons, and marigolds.  In fact, even Russian Thistle (yes - the non-native tumbleweed) is an excellent larval food source for Western Pygmy Blues (though I wouldn't recommend growing it on purpose).  So if you have a nearby vacant lot or neighbor that lets their weeds run wild, at least take solace in the fact that those thorny tumbleweeds are providing a food source for some butterflies!