Sphingid Larvae

[Hank Brodkin]

We have been asked to forward the following observation from southeast Arizona
to Leps-L.

T. Wood/S. Williamson wrote:

>
>
> On another matter entirely, we observed an amazing phenomenon you might
> want to share with the folks on Leps-L:
>
> On our way to Madera Canyon yesterday evening about 5 PM, Tom and I
> encountered a mass movement of sphingid larvae, possibly White-lined
> Sphinx, over a half-mile stretch of Highway 83 around milepost 35 north of
> Sonoita. There were tens of thousands of caterpillars on the road - many
> just yellowish spots on the pavement, others freshly squished, many more
> alive and crawling (it was a horrible sight, but there was nothing we could
> do). The larvae were bright yellow in ground color with ragged black
> longitudinal stripes and reddish eyespots along the lower sides; they had
> well-developed "horns." We couldn't stop long, but I noticed that the
> Whitethorn Acacia along the road on both sides was bare; this and the
> varying sizes of the larvae suggest that the movement was in response to
> resource depletion (if indeed the acacia is a foodplant). When we returned
> about 9 PM, there were a just few live larvae visible; most had either
> moved on or been flattened. Tom and I have never seen a mass movement of
> caterpillars like this, though we've seen spectacular concentrations of
> adult leps and katydids in Mexico. Maybe someone on Leps-L can shed some
> light.
>
> See you soon,
>
> Sheri
>

--
  Hank Brodkin, Nicksville, AZ
              31.44 Degrees N, 110.23 Degrees W
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