Wednesday, May 30, 2012

Another Hawk Moth in the Garden - Snowberry Clearwing

One of my favorite hawk/hummingbird/sphinx moths is the snowberry clearwing (Hemaris diffinis).  With its bumblebee-like appearance, I think it excites the little girl in me - so dangerous looking and yet so gently benign!

I took these photos on the same morning that I captured the images of the white lined sphinx moth that I highlighted in my last post.  The two different species of hummingbird moths seemed to have peaceably divided the yard - the white lined sphinx moths were feeding primarily on the larkspur and the snowberry clearwing seemed to have claimed the Nepeta, or cat mint.

As I examined the photos of the 2 species, I also noted that this moth always seemed to have a foot on the flower it was feeding from, while the white lined sphinx moth never seemed to touch the blossom as it fed except with its proboscis.  I wonder if that was just these 2 individuals?  or is that typical of different feeding patterns between the 2 species?

Like the viceroy imitating the monarch, the snowberry clearwing mimics the bumblebee.  Like the viceroy, the snowberry clearwing is basically defenseless except for its ability to look like it's dangerous.  If you have any questions whether you are seeing a bumblebee moth or a true bumblebee, watch how the insect is feeding.  True bumblebees land on the flower to feed, while bumblebee moths (including the snowberry clearwing) hover in front of the flowers like a small hummingbird.

In the background below, rather blurry, there is a small carpenter bee that was feeding on the Nepeta at the same time as the clearwing.  Notice how perfectly the colors of the two different species coordinate.  The carpenter bee, too, is a bumblebee mimic.  Being solitary bees, although the females of carpenter bees have a stinger, they almost never use it.

As the name suggests, the larvae (caterpillars) of snowberry clearwings feed on snowberry bushes (Symphoricarpos spp.).  Here in Kansas, the most common species of snowberry is actually called coralberry or buckbrush (Symphoricarpos orbiculatus).  According to the literature, snowberry clearwing larvae also eat honeysuckle (Lonicera spp.) and dogbane (Apocynum spp.).   I have not heard of snowberry clearwings becoming numerous enough to actually damage any of these plants.

The photo below is from the Ladybird Johnson Wildflower Center and shows buckbrush used as a groundcover beneath a tree.  I was impressed at how pretty it looks when grown in a garden setting.

After attaining their full size, the caterpillars form cocoons in the leaf litter, where they remain until they emerge as adults.  This is the overwintering stage for this species, although in the south there may also be a second generation or brood during the summer months. Yet another reason to keep leaf litter on the ground as mulch!

There are several other species of bumblebee hawk moths, as this species is sometimes called along with other similarly marked species.  Since their appearance can be variable, the way to tell it is specifically a snowberry clearwing and not one of the other species is the black line going through the eyes and down the side of the thorax (sort of a facial racing stripe) and the black legs.

A last brief note:  there is also another group of moths known as "clearwing moths" that includes several destructive-to-garden species such as the squash vine borer, but this is NOT the group that the snowberry clearwing belongs to.


Kalantikan said...

Hi Gaia Garden, thanks also for finding my site as your comment led me here which is very informative especially for me who loves chasing butterflies but am not so equipped with entomology. We have hawk moth too but I am not so keen in taking their photos. Besides our destroys much of our cucurbits and okra that is really infuriating. But the adults are beautiful, i agree!

By the way, you saw my new site, you should also see my older one, where i put all the butterflies and all insects. I think it is livelier than Oxygen Generators. Thanks.

Gaia Gardener: said...

Glad you stopped by, Kalantikan! Some of the hawk moths can be destructive, but they are such fun moths that I tend to let even the destructive ones live until their numbers get so high that they are literally eating all of the plant. (I'm thinking tomato and tobacco hornworms around here.)

I'll definitely be checking out your other site!

Bluestem said...

I did not know that snowberry clearwing caterpillars like coralberry. I will have to watch for them on my plants. I do see the moths flying around the garden occasionally. Maybe I am providing caterpillar food for them and did not know. Thanks for teaching me something today.

diana cline said...

We have a newly emerged brood of snowberry clearwings here in Bel Air, Maryland (30 miles north of Baltimore). The brood in our yard is feeding on our honeysuckle and butterfly bushes. At first glance I was startled to see such what I thought was a giant bumble bee but as I looked closer I quickly realized they were the same little gems I saw last summer. I captured some video and still shots of these beautiful visitors and will email to you if you'd like.
Thank you for sharing. Diana Cline 8/13/13