Saturday, September 25, 2010


THE BIG THING:  Well, on Thursday, Iza was talking about our hummingbird moth being the adult form of the Tomato Hornworm.  She said that because I told her that.  I told her that because that's what the staff at a local plant nursery told me when I spotted one there.

Guess what?  They were wrong!  I only discovered that today when I idly Googled Tomato Hornworms.  What caught my eye was the adult wingspan being 4-5 inches.  Our little guys only have 2 inch wings.  So I started researching.

It turns out there are 1,200 types of "hummingbird moths".  The adult of the Tomato Hornworm looks like this...

Our little guys look like this...

I couldn't find a picture that looked exactly like ours.  The Snowberry Clearwing (Hemaris diffinis) seemed very close though.  The correct wingspan size, general coloration, and it's one of the few "hummingbird moths" with clear wings. 
But our guys don't have the yellow band at the bottom and the yellow on the back is patchy.  So I started looking for more info on them.  FINALLY, I found this description:

"Identification: Adults are quite variable in appearance; Bumblebee mimic. The thorax is golden or olive-golden in color, abdomen is black dorsally with 1-2 segments just prior to terminal end being yellow to various extent, while black ventrally. H. diffinis is the only eastern species to exhibit blue abdominal tufts on the first black segment in some freshly emerged specimens. Wings mostly clear with reddish brown terminal borders and dark scaling along veins. While wing maculation is too variable to be 100% diagnostic, diffinis typically has very thin terminal borders and the discal cell is elongate and without scales. However, diffinis can always be distinguished from gracilis and thysbe by two diagnostic characteristics: 1) the black band that crosses the eye and travels down the lateral side of the thorax; 2) diffinis always has black legs."

So I conclude that our guys are Snowberrry Clearwings.

The good news is that their caterpillars eat snowberry shrub and honeysuckle leaves.  I have plenty of honeysuckle.   And they don't eat tomato leaves!

Interestingly, I have on occasion found tomato hornworm caterpillars, but I have never seen an adult.  I watch the hummingbirds around the yard carefully, and I'm pretty sure I would have noticed the difference.

Iza felt bad for passing along bad information, so I promised her I would clear her good name...  :)