Large numbers of Whitelined Sphinx Caterpillars in Arizona!!!

Subject: Caterpillars on the march
Location: Northern Arizona
August 17, 2014 5:36 pm
This afternoon we discovered thousands (no, I’m not kidding -THOUSANDS-) of these caterpillars
traveling south across our property. Of course we went straight to the garden to see if that’s where they were coming from, but they were coming right through the fence from the State Land Trust to the north of us! Some of them were nibbling on leaves near the chicken pen, but none of them bothered any of the plants in the garden. We scooped up a bunch of them for this photo and then tossed them to the chickens. The chickens were not impressed.
We’re in Prescott, AZ at about 5,000 ft elevation in oak-chapparal country.
Signature: gnatknees

Population Explosion of Whitelined Sphinx Caterpillars
Population Explosion of Whitelined Sphinx Caterpillars

Dear gnatknees,
These are caterpillars of the Whitelined Sphinx,
Hyles lineata, and they go through periodic cycles that include occasional population explosions in the desert regions of the American southwest.  The last major population explosion we received visual documentation of was in 2007.  Earlier this year, we received a request from a PhD candidate from the University of Arizona to report any masses of caterpillars, and if you are so inclined, you can email [email protected] and make a report.

16 thoughts on “Large numbers of Whitelined Sphinx Caterpillars in Arizona!!!”

  1. Heading south on I-17 about 30 miles from Phoenix hundreds of catapillars were crossing the freeway. Unfortunately most weren’t making it due to heavy holiday traffic and those that do will come up against highway divider. Strange sight.

  2. We had them about that time on our 15 acres outside of Ash Fork. I think they burrowed into the ground. Waiting for the Moth form to emerge.

  3. It’s August 7, 2017 & I’m in Tucson. Over by TIA, there are at least 100, maybe more in the parking lot of Alorica. I have never seen so many & had no clue what they were til I looked the up on Google. They were going into the building & workers at Alorica were bringing them back outside.

  4. I am in Casa Grande,AZ ..there are 1,000’s of them in my yard…they need to leave…how long will they hang around? Can I do anything to get rid of them faster?

  5. Here in Tucson ,Arizona. There are thousands and I mean seriously thousands of these beautiful little caterpillars crawling across the road. Many of which have been hit by passing traffic. But there are still so so many. They cover about a 200 foot stretch of road and who knows where they came from or where they are going

  6. I was on the cholla trail at Thunderbird conservation park this morning and they were everywhere. I was googling what they were and came across your site so thank you for the identification.


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