Tuesday, October 12, 2010

The Euphoria species of Arizona, USA


Overall, in 2010 the numbers of insects in Arizona seemed rather low compared to for example 2007-2008. The extremely dry summer of 2009 and a general increase in temperatures may be the reasons. Small, short-lived and heterotherm, insects are likely to be sensitive to climatic changes. Many species may also reach the limits of their tolerance in hot and arid Arizona. If it gets any hotter and drier here, they may not survive. But so far we are still hoping that this was a temporary decline in numbers and that many species will rebound. Others may be replaced by even more heat adapted species from Mexico.

But even though collection numbers in terms of species as well as individuals were low, I did succeed to complete my virtual collection of the genus Euphoria in the subfamily of  the Flower Chafers, Cetoniinae this year. These are day-active scarabs that fly extremely well with their hard wing covers (first wing pair) closed. A sneak preview of Bill Warner's yet unpublished Checklist of Arizona Scarabaeoidea confirmed that the ten species below are the ones that I can hope to find.

Euphoria Species of Arizona
 
Since I prepared this table, there has been a revision of the genus Euphoria and some names have been changed: E. fulgida holochloris is now E. monticola .  E. fascifera trapezium is now simply E. fascifera, E. kernii was always spelled like this, E. histrionica is now  E. sonorae

Usually I try to photograph living beetles, but I was also delighted to have access to the beautiful and rather complete collection of Patrick Sullivan in Sierra Vista. The specimens of Euphoria devulsa and E. canescens were photographed in this collection. Even Pat's representative for E. canescens came from Mexico, but Barney Streit told me that E. canescens can be found on Sunflowers along  Duquesne Road,Cochise County, Arizona.


E. kernii, which is so common on Opuntia and Prickly Pear flowers further east (Texas), is found in Arizona in a light and a nearly black morph and seems fairly rare.


E. quadricollis (E. arizonica) female and male

E. quadricollis, synonym E. arizonica, 'is sexually dimorphic, with the females tending to be shiny, broader and much darker than the more gracile, tomentose males. The amount of dark spotting on both sexes is variable, but usually much less in males' (Bill Warner via email). Females seem to be less represented in collections which led to some questions about the identification of the female that I found on a tree stump at Copper Canyon, Cochise Co.The image of the male is of a specimen curated at the collection of the University of Arizona.

Euphoria verticalis
E. verticalis, which used to be in the genus Stephanucha when I collected my first specimen in 2007, apparently flies after both rainy seasons: Eric Eaton caught the first one this year in early April when it was buzzing knee-high along stands of wild flowers in Sabino Canyon. In late September I usually find dozens around Annual Sunflowers at the Santa Cruz River and on Desert  Broom bushes in Molino Basin.


  Euphoria leucographa (sepulcralis rufina)


Every year in late summer,  Desert Broom is also the best place to find Euphoria leucographa, our most common Euphoria. With many other insects, the beetles enjoy the sweet juices oozing from the bark of this bush after generous monsoon rains. In October they also frequent the Desert broom flowers.



Euphoria sonorae (histrionica)

 I collected the similarly patterned, smaller E. sonorae in the Huachucas, from lower Carr Canyon to the very top of Miller Canyon. These beetles bury deeply into the flower disc of Sunflowers. This is so typical for them that they can be recognized immediately by their protruding hind ends.



Euphoria inda



I have encountered E. inda only once, at the research Station in Portal buried in flowers of milk weed and then flying off to the mesquite where I photographed it. B. Streit found it west of Portal in thistle flowers.
About this species, Art Evans has an interesting story to tell in his blog - how a specimen made it all the way to Africa to be described there as a newly discovered genus, until Art found it in the South African Museum in Cape town  and dismantled its cover.







 E. monticola (fulgida holochloris) is a great imitator of Carpenter Bees. Like the bees, it spends a lot of time on the wing without landing. when the beetle is buzzing by at high speed the closed shiny fore-wings give a perfect impression of the bee's heavy, dark body.
 Euphoria monticola (photos D. Danforth)





In July and August, I've seen them in the Chiricahuas and the Canelos in similar forested areas under oaks where the ground was covered in moist leaf litter. The male beetles seem to patrol certain paths and clearings, never flying more than a few feet high, probably in search of females on or in the ground. Females are hardly ever collected

Euphoria fascifera trapezium 

 E. fascifera trapezium, which I knew from California, is reported occasionally from our lower desert areas, supposedly associated with pack rat nests. This year it was observed in Tucson in early summer. It seemed to be feeding on fresh Mesquite pods that were bleeding after Mesquite Bug infestation. I finally got hold of one in October when Bruce Mitton collected it for me on blooming Rabbit Bush in his yard in North West Tucson where they regularly breed under his raised planters with lots of composted manure.

The life cycle of this genus is not well described. There seem to be one to two generations per year. The phytophagous larvae have been found in the ground under cow dung and in ant hills. Some adults are reportedly associated with gopher and pack rat nests. Adults feed on pollen, tree-sap, sweet fruit. They have been known to invade bee hives. Rarely, they become pests, damaging young corn or the flowers of roses or mango.


Credits: I'd like to thank Patrick Sullivan for permission to photograph his collected specimens, Bruce Mitton for the life E. fascifera, Bill Warner and Barney Streit for additional information and D. Danforth for the permission to use his excellent photos of E fulgida that he originally submitted to www.bugguide.net
 Monographic revision of the genus Euphoria (Coleoptera: Scarabaeidae: Cetoniinae)

11 comments:

  1. Congratulations on completing your Arizona representation of this beautiful genus. Of those species I have only fulgida holochloris (from Texas), inda (from Missouri), kernii (from numerous localities), and canescens (from Mexico). I do have a 9 specimens of a species that I collected in Arizona that had me stumped - I sent them to Brett Ratcliffe, and he sent them back with "What are these?!" written on an identification label.

    ReplyDelete
  2. Thanks Ted!
    Those unidentified ones sound interesting, could you send me a photo? I guess there are lots of undescribeds in AZ , but I didn't think that something as big as Euphoria had been overlooked. Bill Warner would be interested, I'm sure

    ReplyDelete
  3. Yes, I've been meaning ask Bill for his opinion. Actually, I should check them against these excellent photos first!

    ReplyDelete
  4. I have more than enough of E. sepulc(h)ralis and verticalis, histrionica (a few) so if you'd like any?

    ReplyDelete
  5. Henry Hespenheide said via email:

    Euphoria canescens is clearly a mimic of clytrine chrysomelids that I hadn't known about. Thanks for posting the pix on your website.

    ReplyDelete
  6. Very cool. Any idea why they were called Euphoria?

    ReplyDelete
  7. Hi Margarethe. I'd be grateful for any extras you care to send my way :)

    ReplyDelete
  8. Via email:
    Dear Margarethe,
    I am currently a last year doctoral student at the University of Nebraska working under the supervision of Dr. Brett Ratcliffe. For my dissertation research, I am working on a revision of the genus Euphoria (Coleoptera: Scarabaeidae: Cetoniinae). I found you post on the species of Arizona with some spectacular pictures. I was wondering if you could give me permission to use them in my upcoming monograph dealing with this group. Hi-res would be excelent if you have them. Of course all credit will be given to you.

    Regards,
    Jesús O.

    ReplyDelete
  9. I think I found a specimen of E. fascifera trapezium. Who would I go to to appraise my specimen and find out if it's the real deal?

    ReplyDelete
  10. What is the Euphoria Fascifera Trapezium's nickname. I think I have found a specimen for my collection and i want to collect the scientific and nickname for it.

    ReplyDelete