Excerpts from Jim Conrad's
Naturalist Newsletter

from the February 22, 2019 Newsletter issued from Rancho Regensis north of Valladolid, Yucatán, MÉXICO;
elevation ~40m (~130 ft), N~20.876°, W~88.170°
BIG-EYED CATERPILLAR WEARING LIPSTICK

"Want to see a big-eyed caterpillar wearing lipstick?

That's what I heard at Genesis resort in Ek Balam when owner Lee turned her computer screen toward me. Above you see what I beheld. A close-up of that grinning "face" appears below:

And a better view of how the face fits at the front of the plump caterpillar body is shown below:

So, the "face" consists of markings on the caterpillar's back, immediately behind the head. In the above picture the actual head is kept bent down, touching the table. But of course if you're a caterpillar-eating bird or lizard, the painted-on face with those big eyes staring at you, and the red lips seeming ready to snap in your direction, may be unnerving enough to make you go away.

Genesis visitor Heather Holm of Canada had snapped the caterpillar's picture with her phone, emailed it to Lee, Lee forwarded it to me, and now you're seeing it, thanks to Heather.

Thinking it was a hornless hornworm, the caterpillar stage of a sphinx moth, family Sphingidae, on the Internet I made a quick image search on the key words "Sphingidae caterpillar Yucatan" and quickly came up with an image similar to ours, assigned to the genus Madoryx.

At sphinx moth expert Bill Oehlike's page listing the various species of Madoryx, the only species listed as occurring in Mexico is MADORYX PLUTONIUS DENTATUS*, though for nearby Belize Madoryx bubastus butleri is mentioned.

I'll file our pictures on the Internet under Madoryx plutonius and maybe later an expert will confirm it. Hardly any information is available about its life history.