Brazil Bugs #15 – Formiga-membracídeos mutualismo

Of the several insect groups that I most wanted to see and photograph during my trip to Brazil a few weeks ago, treehoppers were near the top of the list.  To say that treehoppers are diverse in the Neotropics is certainly an understatement – South America boasts an extraordinary number of bizarre and beautiful forms that still, to this day, leave evolutionary biologists scratching their heads.  The development of this amazing diversity is a relatively recent phenomenon (thinking geological scale here), as there are no known membracid fossils prior to Oligo-Miocene Dominican and Mexican amber – well after the early Cretaceous breakup of Gondwanaland split the globe into the “Old” and “New” Worlds.  With its origins apparently in South America, numerous groups continued to spring forth – each with more ridiculous pronotal modifications than the last and giving rise to the dazzling diversity of forms we see today.  Even North America got in the evolutionary act, benefiting from northern dispersal from South America’s richly developing fauna via temporary land bridges or island stepping stones that have existed at various times during the current era and giving rise to the almost exclusively Nearctic tribe Smiliini (whose species are largely associated with the continent’s eastern hardwood forests).  Only the subfamily Centrotinae, with its relatively unadorned pronotum, managed to successfully disperse to the Old World, where it remains the sole representative taxon in that hemisphere.  With a few notable exceptions, treehoppers have virtually no economic importance whatsoever, yet they enjoy relatively active study by taxonomists, evolutionists, and ecologists alike – due almost completely to the bizarreness of their forms and unique mutualistic/subsocial behaviors.

I did manage to find a few species of treehoppers during the trip (a very primitive species being featured in Answer to ID Challenge #4 – Aetalion reticulatum), and of those that I did find the nymphs in this ant-tended aggregation on a small tree in the rural outskirts of Campinas (São Paulo State) were perhaps the most striking in coloration and form.  Most were jet black, although a few exhibited fair amounts of reddish coloration, and all exhibited sharply defined white bands of wax and long erect processes on the pronotum, mesonotum, and abdomen.  I’ve seen a fair number of treehopper nymphs, but I did not recognize these as something I had seen before, and given the incomplete state of immature taxomony I feared an identification might not be possible.  Still (and I know this is probably beginning to sound like a broken record), I gave it the old college try.

I usually like to start simple and get more creative if the results aren’t satisfactory, so I went to my old friend Flickr and simply typed “Membracidae” as my search term.  Predictably, pages and pages of results appeared, and I began scanning through them to see if any contained nymphs at all resembling what I had.  After just a few pages, I encountered this photo with very similar-looking nymphs, and although no identification beyond family was indicated for the photo, I recognized the lone adult sitting with the nymphs as a member of the tribe Aconophorini – a diverse group distinguished from other treehoppers by their long, forward-projecting pronotal horn.  Luck was with me, because I happen to have a copy of the relatively recent revision of this tribe by Dietrich and Deitz (1991).  Scanning through the work, I learned that the tribe is comprised of 51 species assigned to three genera: Guayaquila (22 spp.), Calloconophora (16 spp.), and Aconophora (13 spp.).  The latter two genera can immediately be dismissed, as ant-interactions have not been recorded for any of the species in those two genera – clearly the individuals that I photographed were being tended by ants.  Further, the long, laterally directed apical processes of the pronotal horn, two pairs of abdominal spines, and other features also agree with the characters given for nymphs of the genus Guayaquila.  In looking at the species included in the genus, a drawing of a nymph that looked strikingly similar to mine was found in the species treatment for G. gracilicornis.  While that species is recorded only from Central America and northern South America, it was noted that nymphs of this species closely resemble those of the much more widely distributed G. xiphias, differing by their generally paler coloration.  My individuals are anything but pale, and reading through the description of the late-instar nymph of the latter species found every character in agreement.  A quick search of the species in Google Images was all that was needed to confirm the ID (at least to my satisfaction). 

In a study of aggregations of G. xiphias on the shrub Didymopanax vinosum (Araliaceae) in southeastern Brazil, Del-Claro and Oliveira (1999) found an astounding 21 species of associated ant species - a far greater diversity than that reported for any other ant-treehopper system.  The most frequently encountered ant species were Ectatomma edentatum, Camponotus rufipes, C. crassus, and C. renggeri, and after perusing the images of these four species at AntWeb I’m inclined to believe that the ants in these photos represent Camponotus crassus (although I am less confident of this ID than the treehoppers – corrections welcome!).  The authors noted turnover of ant species throughout the day in a significant portion of the treehopper aggregations that they observed, which they suggest probably reflects distinct humidity and temperature tolerances among the different ant species and that might serve to reduce interspecific competition among ants at treehopper aggregations.  Since treehopper predation and parasitism in the absence of ant mutualists can be severe, the development of multispecies associations by G. xiphias results in nearly “round-the-clock” protection that can greatly enhance their survival.

Update 3/3/11, 9:45 a.m.:  My thanks to Chris Dietrich at the Illinois Natural History Survey, who provided me in an email exchange some clarifying comments on the origins and subsequent dispersal of the family.  The first paragraph has been slightly modified to reflect those comments.

REFERENCES:

Del-Claro, K. and P. S. Oliveira. 1999. Ant-Homoptera interactions in a Neotropicai savanna: The honeydew-producing treehopper, Guayaquila xiphias (Membracidae), and its associated ant fauna on Didymopanax vinosum (Araliaceae). Biotropica 31(1):135–144.

Dietrich, C. H. and L. L. Deitz.  1991.  Revision of the Neotropical treehopper tribe Aconophorini (Homoptera: Membracidae).  North Carolina Agricultural Research Service Technical Bulletin 293, 134 pp.

Copyright © Ted C. MacRae 2011

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About Ted C. MacRae

Ted C. MacRae is a research entomologist by vocation and beetle taxonomist by avocation. Areas of expertise in the latter include worldwide jewel beetles (Buprestidae) and North American longhorned beetles (Cerambycidae). More recent work has focused on North American tiger beetles (Cicindelidae) and their distribution, ecology, and conservation.
This entry was posted in Formicidae, Hemiptera, Hymenoptera, Membracidae and tagged , , , , , , , , , , . Bookmark the permalink.

47 Responses to Brazil Bugs #15 – Formiga-membracídeos mutualismo

  1. myrmecos says:

    Nice shots, Ted. Your ants look like C. crassus to me, although there are a great many similar species in that complex (including C. brasiliensis & C. cameranoi) that can’t easily be separated without a clearer photo.

    • Okay, thanks for the opinion.

      There you have it folks, Camponotus crassus… maybe!

      • James C. Trager says:

        Alex has more recent experience wth that fauna than I, but based on the longer and whiter pilosity of your ants, Ted, I’m leaning toward C. cameranoi. Whadaya think, Alex?

        Either way, the hoppers are awesome!

        BTW, I think good old Publilia around here might have numberrs of ant species that visit them rivaling that figure of 22.

  2. Interesting. I’ve never seen anything like these. I also had no idea that treehoppers might be attended by more than one ant species.

  3. Kirk says:

    Love the racing stripes!

  4. david winter says:

    Amazing (bugs and photography!)

    I was hoping you’d run into some tree hoppers in your travels, having seen some of the weird head-gear they sport and these guys definitely don’t disappoint

    • Thanks, David. I wish I’d run into some of the species in that link, but I’ve still got one pretty good one to show (although the photos don’t really do it justice).

  5. jason says:

    They’re really cool looking, Ted. As Kurt said, I love the racing stripes.

    Several years ago I discovered ants tending aphids on the bushes outside my patio. Since then, I’ve spent many a warm day standing motionless watching the whole scene. Such relationships between ants and other insects are fascinating!

  6. Margarethe says:

    You came back with some great stuff!

  7. Pingback: Circus of the Spineless #60! « Bug Girl’s Blog

  8. Staxxs says:

    Nice blog looking forward on reading more post form you.

  9. These are some nasty, yet handsome, looking bugs. Why do ants tend to them? Very interesting. How did you photograph them out in the field? Thanks for your time!

    • The treehoppers excrete honeydew, which has concentrated sugars from the plant sap that they feed on. Ants love the honeydew and protect the treehoppers because of this. The treehoppers are not easy to photograph in the field – they are easily disturbed which causes them to disperse. I managed to get these photos by carefully approaching them and gently holding with one hand the branch they were sitting on while working the camera with the other hand.

  10. Wow … thank you for sharing those photos!

  11. Wild looking bugs. My uncle is an entomologist, so I like bug pictures every so often.

  12. Great photos! What a crazy looking bug the treehopper. First time I have never seen anything like him!
    Amazing Photos!

  13. Passing Once says:

    What a spectacular image or images ^_^. They are nature’s little fashionistas, aren’t they? :)

  14. I can see the beauty in the shots, but sheesh…could you respect those of us with serious bug phobias?
    ;)

    Thanks for the nightmares!

  15. klynke says:

    OMG – these are WONDERFUL! Bug phobics, get a grip. Work on it. Try and overcome your fear. Bugs are marvelous, and they rule the world!

  16. Lili says:

    Fotografados assim de perto até parecem bonitos.

  17. leadinglight says:

    Those are magnificent photos. Did you use macro lens?

  18. Jennifer Barricklow says:

    I don’t know what I enjoyed more — your lovely photos or your narrative about identifying the little critters. Both appeal tremendously to the amateur biologist in me. Thanks so much for sharing such an interesting post, and congratulations on being Freshly Pressed!

  19. Wow – thank you to all the visitors from “Freshly Pressed.” Made my day!

  20. bethcams says:

    They are big, pretty, prone to sitting motionless, and they like to hang out in vegetation at a very comfortable eye-level.

  21. upay says:

    scrammmmmmmm……. T.T

  22. enjoibeing says:

    wow those look like aliens! they look like they could hurt someone. cool photos!

  23. interesting and amazing

    thanks

  24. fey's diary says:

    You had a lot of ideas shared. Thank you for that.

  25. Great shots but boy, do they give me the creeps….

  26. arent they beautiful close up??

  27. Great photos, wow, they are soo tiny. Congrats on being Freshly Pressed.

  28. manustawee says:

    They are so cute !! hehe :D

  29. Kim says:

    Wow, I haven’t seen such insects before

  30. Sheryll says:

    Wow! Those are some bugs!! Great story and congrats on being Freshly Pressed!

  31. sarahnsh says:

    The pictures are great, and I love the pictures where you can see their little eyes peeking out. The coloring of the tree hopper is just so pretty, and they do look quite alien with their little spikes on their body!

  32. stylistnc says:

    Those are some crazy looking bugs. I never knew they existed and love the photos!!

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