DISTRIBUTION: The Tricolor Buckmoth, Hemileuca tricolor (wingspan: males: 39-45mm; females: 58-61mm) flies in desert thornscrub from southern Arizona and southwestern New Mexico, south into Mexico: Sonora. " Females are larger and darker than males. Upperside of forewing is gray to brownish gray with white marginal, submedian, and postmedian bands. The submarginal area may be lighter colored than the rest of the wing. Upperside of hindwing is white in males and white to pale brown in females; females usually have a pink tint. " Hemileuca tricolor male, copyright Kirby Wolfe

FLIGHT TIMES AND PREFERRED FOOD PLANTS:

This species flies from January-April.

Russell Witkop collected adult Hemileuca tricolor on March 7 and 8 in Sells, Arizona, on Highway 86. Moths were stil flying at 3:00 am.

Littleleaf paloverde (Cercidium microphyllum), mesquite (Prosopis juliflora) and catclaw acacia (Acacia greggii) are the favorite host plants of the larvae.

Hemileuca tricolor habitat, near Ajo, Arizona, courtesy of Russell Witkop.

Hemileuca tricolor female from Arizona. Photo by Bruce Walsh.

ECLOSION, SCENTING AND MATING:

Mating begins after dark and females may begin laying eggs immediately after. Males use well developed antennae to track the female's pheromone plume. Photo courtesy of Bruce Walsh.

EGGS, LARVAE, COCOONS AND PUPAE:

Eggs are deposited in rings around twigs of the host plants, and hatch in July. Young caterpillars feed together. Before pupating fully-grown caterpillars wander around on the ground and then make loose cocoons of debris and silk in which they pupate and overwinter.

Hemileuca tricolor courtesy of Jim Tuttle.

Matt Curtis writes, "Hi Bill, I thought you might be able to ID this larvae for me or know someone who could. I believe it is H. tricolor since it is about the only larvae mentioned as out in late summer.

"I found it 14 September near Patagonia Lake in Santa Cruz CO., AZ. I was looking for Agapema habitat in new locations and decided to check out some of the ocotillo for calleta for a while when I noticed this small larvae and said, darn that looks like a Hemileuca. It looks like the tricolor larvae photo in WIld SIlkmoths, so I am assuming that is what it is. What was odd was the food plant, there was an acacia right beside the ocotillo, so I thought that maybe it had just become lost. I placed the larvae in a shoe box with both ocotillo and acacia, and it has spent the last two and a half days feeding on the ocotillo and ignoring the acacia (and some mesquite I added also).

"Could this possibly be a new food plant? That would be neat!"

I reply, "Hi Matt, It certainly appears to be Hemileuca tricolor. Ocotillo would be a new host. The only Saturniidae species that I have read about which uses Ocotillo as a larval host is Eupackardia calleta. Perhaps you confused the larva. It knew you were looking for calleta, so ..." Chuckle.

"Thanks for the images. Hemileuca hualapi ia also a late summer feeder and can be found in southern Arizona, but that species is a grass feeder."

Hemileuca tricolor fifth or sixth instar, Patagonia Lake, Santa Cruz County, Arizona,
September 14, 2012, courtesy of Matt Curtis.

Hemileuca tricolor fifth or sixth instar, Patagonia Lake, Santa Cruz County, Arizona,
September 14, 2012, courtesy of Matt Curtis.

Hemileuca tricolor male (Mexico) courtesy of Dr. Manuel A. Balcazar Lara

Larval Food Plants

It is hoped that this alphabetical listing followed by the common name of the foodplant will prove useful. The list is not exhaustive. Experimenting with closely related foodplants is worthwhile.

Cercidium microphyllum....... Ocotillo (MC) Prosopis juliflora Acacia greggii

Littleleaf paloverde Ocotillo Mesquite Catclaw acacia

Return to Return to Main Index

Return to Hemileuca Genus