Hemaris thetis, photo courtesy of T.W. Davies.

This site has been created by Bill Oehlke.
Comments, suggestions and/or additional information are welcomed by Bill.

TAXONOMY: Family: Sphingidae, Latreille, 1802 Subfamily: Macroglossinae, Harris, 1839 Tribe: Dilophonotini, Burmeister, 1878 Genus: Hemaris (Dalman, 1816) ........... Species: thetis (Boisduval, 1855)

Those Sphingidae west of the continental divide (western Montana, Idaho, Washington, Oregon, Nevada, Utah, California, Arizona, western Wyoming, western Colorado, western New Mexico), previously thought to be H. diffinis are now determined to be the recently elevated species, Hemaris thetis. It is my understanding that the moths described as H. senta also belong to H. thetis as thetis was described (Boisduval, 1855) before senta was described [Strecker, 1878].

Subsequently thetis was synonymized with diffinis, but, based on paper by Christian Schmidt Journal of the Lepidopterists' Society 63(2), 2009, 100-109. Hemaris thetis (Boisduval, 1855) (Sphingidae), H. thetis in now recognized as a distinct species, based on DNA and genitalia analysis.

In some places just East of the Divide (Colorado, Alberta) overlap of ranges of H. thetis and H. diffinis is known and precise determinations, by photographs only, will be next to impossible.

Thanks to Edna Woodward and Ryan St. Laurent for alerting me of this change. It will be a little while before I get the changes made on the Sphingidae of the Americas website.

I will shortly create the H. thetis page and will move all appropriate images off the original H. diffinis page and add them to the new page.

Hemaris thetis, Whitefish, Flathead County, Montana,
May 31, 2018, courtesy of Richard Kurth.

DISTRIBUTION:

Hemaris thetis, the Thetis Clearwing Moth or Bee Hawk Moth (wingspan: approximately 1 1/2" (30mm)) flies in British Columbia, Canada. In the U.S. Hemaris thetis flies in all of Washington, Oregon, California Idaho, Utah and Arizona. It can also be found in extreme western parts of Montana, Wyoming, New Mexico and in the western half of Colorado, west of the Continental Divide.

Note the rusty color near the wing-roots. This species tends to be slightly smaller than the very similar Hemaris diffinis.

Visit Hemaris thetis, Gabriola Island, British Columbia, Canada, June 28, 2008, courtesy of Jean Wyenberg.

Visit Hemaris thetis, Mt. Hamilton, Santa Clara County, California, May 20, 2009, Owen Holt.

Hemaris thetis, from southern British Columbia,
courtesy of Jeremy B. Tatum and Dr. John Snyder.

Hemaris thetis is a very variable species, but almost always the abdomen sports contrasting black and yellow hairs, the ventral surface being quite black. The legs also tend to be quite dark and there is a black mask running across the eye and along the sides of the thorax.

Adults mimic bumblebees and are quite variable, both geographically and seasonally. The wings are basically clear, with dark brown to brownish-orange veins, bases and edges. The thorax is golden-brown to dark greenish-brown. The abdomen tends to be dark (black) with 1-2 yellow segments just before the terminal end. These yellow segments are in much sharper contrast to the rest of the abdomen than in somewhat similar species. Also note the relatively narrow dark outer margin of the hindwing. Most fresh specimens also have some blue "fur" tufts highlighting the first black band on the abdomen.

The dorsal surfaces of the legs in Hemaris thysbe are whitish-pale grey, and the legs of Hemaris gracilis are red.

FLIGHT TIMES:

There are probably two broods of this montane species annually from June - August depending upon latitude. In Josephine County, Oregon, Edna Bottorff reports them on the wing in June and again in August. The moth is seen along forest edges, in meadows, gardens and brushy fields. Adults like to nectar at lantana, dwarf bush honeysuckle, snowberry, orange hawkweed, thistles, lilac and Canada violet.

Hemaris thetis necaring at milkweed, Wolf Creek, Josephine Co., Oregon,
June 11, 2009, courtesy of Edna Woodward.

ECLOSION:

Regular sized moths emerge from seemingly small pupae when this species is reared in captivity.

Larvae pupate in thin walled cocoons under leaf litter.

SCENTING AND MATING:

Females call in the males with a pheromone released from a gland at the tip of the abdomen.

EGGS, LARVAE, PUPAE:

David Wikle obtained eggs from a female, in San Jacinto Mountains, Riverside Co. California, above Lake Hemet on June 24, 2007. His image of an egg is to the right. David indicates pupation began on July 15-16 so progress was quite rapid. His images of first instars and second instar, are below. David also indicates the species, is flying on Mt Baldy in the San Gabriel Mountains, San Bernardino Co., California on July 11, 2009. Moths are expected in nine days to two weeks.

Caterpillars pass through five instars and are pale green on the back and darker green on the sides, with numerous white flecks in the final instar. The anal horn is bright yellow at base and blue-black at the tip.

Edna Woodward sends the following images of various instars.

Hemaris thetis, first or second instar?, Wolf Creek, Josephine County, Oregon,
June 30, 2011, courtesy of Edna Woodward.

Hemaris thetis, second or third instar?, Wolf Creek, Josephine County, Oregon,
July 2, 2011, courtesy of Edna Woodward.

Hemaris thetis, second or third instar?, Wolf Creek, Josephine County, Oregon,
July 4, 2011, courtesy of Edna Woodward.

Hemaris thetis, second or third instar?, Wolf Creek, Josephine County, Oregon,
July 5, 2011, courtesy of Edna Woodward.

Hemaris thetis on wild honeysuckle, Wolf Creek, Josephine County, Oregon,
courtesy of Edna Woodward.

Hemaris thetis, fourth instar?, Wolf Creek, Josephine County, Oregon,
July 15, 2011, courtesy of Edna Woodward.

Hemaris thetis, final instar, Wolf Creek, Josephine County, Oregon,
July 22, 2011, courtesy of Edna Woodward.

Hemaris thetis, prepupal, Wolf Creek, Josephine County, Oregon,
July 30, 2011, courtesy of Edna Woodward.

Hemaris thetis, fresh pupa (will darken shortly), Wolf Creek, Josephine County, Oregon,
July 30, 2011, courtesy of Edna Woodward.

Edna Woodward records the following rearing observations from July 2- July 22:

"I never saw a single change of instar, nor a sign of a shed skin, and I had it sitting right beside me the whole time, looked at it off and on all day every day.

"On July 22, he was fully grown, and by the next morning he was storming around his house like a bear with a sore butt. He would flop around wildy if I went near him. I put him in the quiet room and this am (July 28, without any color change) he is sitting very still on top of the paper towels and has sweated much, so I expect he will pupate soon."

I suspect larvae of this species eat their discarded skins right after molting, otherwise Edna, who is very observant, would have seen them. She reared the found larva on wild honeysuckle.

Edna has also directed me to another webpage where there is documentation of an Hemaris thysbe larva promptly turning to devour the exuvia after molting, so this may be a common practice with Hemaris species.

Hemaris thetis, hardened pupa, Wolf Creek, Josephine County, Oregon,
August 1, 2011, courtesy of Edna Woodward.

Larval host plants include Snowberry (Symphoricarpos), honeysuckle (Lonicera), Coralberry, viburnums, low-bush cranberry and hawthorn..

Hemaris thetis, British Columbia, courtesy of G. A. Hardy

Larvae can vary, but in most cases the final instar has a long black anal horn, lighter or yellow near the base. Spiracular circles tend to be very large, prominent and black, but there are regional differences. Western species (H. thetis) often have a shorter, thicker horn and much smaller and lighter spiracular circles as compared to the very similar eastern species H. diffinis.

Green colouration of larvae is typical, but just before pupation larvae often darken to purplish-brown.

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Those who first published descriptions and assigned scientific names to many insects, simply chose names of biblical or mythological origin without any real descriptive qualities. Their purpose was simply to set a standard for purposes of identification by assigned name. On some occasions, names, mostly of Latin or Greek origin, were chosen to signify a particular character of the genus or of an individual species.

The genus name "Hemaris" is probably a Latin adjective form for blood. It may have been chosen by Dalman based on the burgundy-red scales on the wings.

The original choice of "Macroglossa" would have been for the relatively large, glassy (clear) areas of the wings.

In ancient Greek Mythology "thetis" is the silver-footed sea nymph.

The pronunciation of scientific names is troublesome for many. The "suggestion" at the top of the page is merely a suggestion. It is based on commonly accepted English pronunciation of Greek names and/or some fairly well accepted "rules" for latinized scientific names.

The suggested pronunciations, on this page and on other pages, are primarily put forward to assist those who hear with internal ears as they read.

There are many collectors from different countries whose intonations and accents would be different.

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Enjoy some of nature's wonderments, giant silk moth cocoons. These cocoons are for sale winter and fall. Beautiful Saturniidae moths will emerge the following spring and summer. Read Actias luna rearing article. Additional online help available.

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