Rich Ditch's Photography Blog

August 30, 2010

Cutworm, Horn Worm, Tomato Worm

Filed under: behavior, curiosities, Non Birds — richditch @ 3:36 pm
Cutworm, Horn Worm, Tomato Worm

Cutworm, Horn Worm, Tomato Worm

While driving home from a visit to the nearby Gila River tribal lands I realized that the greenish-yellow “stuff” I saw blowing across the highway was in fact a massive migration of fat caterpillars. Their yellow bodies caught the sunlight and winked at me each time they flexed their bodies, and I couldn’t resist stopping briefly for a couple of photos. Although most were very yellow, this one appeared more green and contrasted nicely with the painted roadside curb.

My first thoughts were these were tobacco or cotton horn worms – the sort that turn into large brown moths. Cotton is an important crop in the area. I found an illustration in an old Golden Guide that led me to believe they were Yellow-striped Army Worms. I posted a quick report to the AZ birding list serve – a great resource for anything nature-related in the desert southwest – and was directed to the Common Caterpillars of SE Arizona web site. Scrolling down to the fifth entry shows a good match: the White-lined sphinx (Hyles lineata).



  1. Looks like a good match Rich, based on the link you provided. It says they can be so common as to make the roads too slippery to drive on. I had that happen once with grasshoppers – slippery road and had to clean off my radiator several times to keep from overheating – not fun. I really should learn another lesson from you and keep my camera more available for these unexpected, non-feathered opportunities.

    Comment by rondudley — August 30, 2010 @ 6:21 pm

  2. I was in awe Sunday! Millions of bright yellow catepillars sprinting across the road in the same direction committing mass suicide on Pecos was absolutely insane! I’ve never seen anything like this. I was left with many questions. What kind of catepillars were they? What were they doing running across the street? Why were they all moving in the same direction? Thanks for posting this on your blog and helping me understand what they were….now if we only understood why they were all headed north/west…

    Comment by jmp — August 31, 2010 @ 2:16 pm

RSS feed for comments on this post. TrackBack URI

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Blog at

%d bloggers like this: