Wednesday, September 18, 2013

Insects of the Button Bush

Two weeks ago my friend Ned Harris alerted me that the Button Bushes in Sabino Canyon were blooming. That meant photo opportunities par excellence for all kinds of nectaring insects.

Button Bush, Cephalanthus occidentalis, in Sabino Canyon
Button Bush or Button Willow, Cephalanthus occidentalis, in the family Rubiaceae, can be found in all states east of the Rockies, but only in Arizona and California in the West. The perennial shrub has a high water use, so it grows along  Sabino Canyon Creek that is finally running again. I have yet to find it elsewhere.  Button Bush may like locations higher on the rocky bank than my other favorite insect bush the Seep Willow Baccharis salicifolia that is much more common and grows within sandy creek beds where it hangs on during floods and thrives on the nutrients that the water leaves behind.

Ned Harris in a field of Datura that's also in full bloom in Sabino Canyon
On Sept. 4, I joined Ned on one of his photo excursions and I was amazed how much the bushes had grown over the last three years.  So much so that a lot of insects were out of reach for my macro lens and I am relying on Ned who is taller and has a longer lens for most of this blog's images. Just kidding, Ned's photos are just way better than mine.

left: Carpenter bees: Xylocopa  tabaniformis, and californica Photo N. Harris. right: Sonoran Bumblebee Bombus sonorus
Even though we ignored the honey bees, we found plenty of native bees and bumblebees who shared the nectar with all kinds of big wasps. 

Top:  Pepsis grossa and another Tarantula Hawk
Below: Campsomeris tolteca, Prionyx sp, Polistes flavus
Very large Tarantula Hawks, Pepsis grossa, appeared in two color forms: Orange-winged (xanthic) and black-winged (melanic). The two color forms are not often seen in the same locality, but the black one was too large to be the similar P. mexicana. The scoliid Campsomeris tolteca and the sphecid Prionyx were also among the giants of their families.

Top: Gulf Fritillary, Queen, Monarch
Middle: Painted Lady, Bordered Patch, Arizona Metalmark
 Bottom: Black Swallowtail, Southern Dogface, Acacia Skipper
most photos Ned Harris 
Ned uses a long lens that isn't a dedicated macro, so he concentrates mostly on insects above 1 in body length, and so of course he loves all butterflies. We found everything from big Brush-foots (Nymphalidae) and Swallowtails (Papilionidae) to Sulfurs (Pieridae), Metalmarks (Riodinidae) and Skippers (Hesperiidae).

Pipevine Swallowtail by Ned Harris
My favorites are without doubt our very common Pipevine Swallowtail. These butterflies hardly ever sit still but keep flapping their wings because the slim buttonbush branches can hardly support their weight.  Much rarer is the similar Black Swallowtail but Ned got the nice shot in the group collage above.

White-lined Sphinx by Ned Harris
The White-lined Sphinx solves the weight problem by not landing at all but hovering over the flowers while nectaring. Because of this ability several moth species in the family Sphingidae have earned the common name 'Hummingbird Moth'.

Strigoderma pimalis and Cotinis mutabilis (Green June Bug or Fig Beetle)
Disappointingly few beetles showed up. I had expected a few sugar-loving cerambycids, but we found only two species of scarabs. But it was a blustery, overcast day and flying and cold starts in particular are much more costly for a beetle than for a butterfly with its much greater wing area.

Mexican Amberwing, Yellow-bellied Bee Assassin, Green Lynx spider
As usual in high traffic areas, there was a number of ambush predators. Dragonflies  kept an overview from an elevated perch, whereas spiders and assassin bugs were lurking in the foliage and even on the flowers.

The Buttonbushes of Sabino Canyon are definitely worth a yearly visit, even though they bloom in the hottest, muggiest time of the year. It's rare that I'm not envious of Ned's long lens and high performance camera, but this time I was quite happy to carry only my point-and-shoot and small binoculars, especially as I could count on Ned's generosity to share his photos!



  1. Absolutely Awesome! Amazing shots! My favorite subject! (Hymenoptera).
    The shot of the Bee Assassin is priceless! (I'd love to keep one in captivity for a while...)

  2. Wonderful post! I've just spent a day in a suburban park, trying to identify all the bugs I could for my blog and kept thinking how easy you make it look, haha! I love that you know these critters down to species level - most guidebooks I've seen only attempt genus level for many insect groups.

    1. Here on my home turf I'm pretty confident about the species. If you are in the US just submit photos to bugguide and we can help you with the Ids. the turn around time is very fast

    2. I'm going to go on holiday over there at some point and make you regret offering that! ;-)

  3. I wonder where in California these bloom? I did a little foray into the desert yesterday and it's yellow composites, all over (from our rains). But not that much insect diversity on them (mostly Honey Bees).

  4. Love the butterflies in your post. Being from a hot climate, i can see some of them are visitors in my climate too specially painted lady and one swallowtail. Just love your website.