Bichos Argentinos #4 – Balancing Act

Nezara viridula (southern green stink bug) | Pergamino, Pcia. Buenos Aires, Argentina

I encountered this adult Nezara viridula (southern green stink bug) (Hemiptera: Pentatomidae) in a soybean field in Buenos Aires Province, Argentina.  I liked the way it balanced itself on the leaf on which it was sitting to keep its body level.

Copyright © Ted C. MacRae 2011

Brazil Bugs #4 – Mais dos percevejos

I found mais dos percevejos (more of the leaf-footed bugs) on the still-unnamed pink flowering shrub in back of the hotel in Campinas, Brazil.  Not only am I convinced that they truly do belong to the family Coreidae (for the reasons mentioned in the earlier post and below), but also that despite the different color patterns shown by the two individuals in that post that they are indeed a single species.  I also found the above individual, representing an even more heavily melanized version than the two shown previously.  In looking at a large number of individuals on the shrubs (and subsequently encountering them in a different part of Campinas over the weekend), it became clear that there were not just two distinct color forms but a broad range of variability.  I could believe maybe two species occurring together on a common resource, but it seems unlikely that each color variation represents a different species.  Thus, it now seems that there is one highly variable species visiting these flowers.

I had an idea on how to find the name of this species that almost worked.  Rather than Googling “leaf-footed bug” or “Coreidae,” I tried “percevejo” instead, along with Brazil or Brasil.  There were 3 or 4 photographs that showed up in the images search that I recognized instantly as belonging to the same species.  Unfortunately, none of the links where the photos were found gave any information more specific than family (all, however, agreeing with family Coreidae).  I think it’s time to send an email to Harry Brailovsky, a coreid specialist at the Instituto de Biologia (UNAM) in Mexico City.

Photo 1: Canon MP-E 65mm 1-5X macro lens (ISO 100, 1/200 sec, f/13).
Photo 2: Canon 100mm macro lens (ISO 100, 1/200 sec, f/16).
Both photos: Canon 50D, Canon MT-24EX flash w/ oversized DIY concave diffuser. Typical post-processing (levels, color, unsharp mask).

Last minute edit: I just heard back from Harry Brailovsky as I was ready to post (thank you Harry!).  The insect is, indeed, a species of Coreidae, which he identified as a member of the genus Hypselonotus.  I did some searching online to see if I could find any additional clues as the species identity – I found no images that looked right but did find this key to the Hypselonotus of Costa Rica.  The key relies on some ventral characters, and I’m a little uneasy about using it for something from southern Brazil, so I think I’ll just wait until Harry has a chance to look it up when he returns to the museum.

Second update 1/26/11:  Harry has confirmed the species as Hypselonotus interruptus, which was mentioned but not included in the key that I linked to above.  The only online images I have found of this species are at this link. Either Harry is wrong (unlikely), the photos in the link are misidentified (maybe), or the species is enormously variable (perhaps quite likely).

Copyright © Ted C. MacRae 2011

A “leafless” leaf-footed bug

Merocoris distinctus feeding on flower stem of Coreopsis lanceolata.

This is Merocoris distinctus, a true bug in the family Coreidae whose members are usually recognized by their distinctive flattened hind tibiae (and hence the common name, leaf-footed bugs). This diminutive species, however, lacks that character, instead sporting strangely curved hind tibiae along with club-shaped (incrassate) hind femora. It’s a chunky little species – much smaller than the typical leaf-footed bugs seen across North America, and is most often encountered in grassland habitats where it feeds on herbaceous plants such as goldenrod, Solidago spp. (Slater and Baranowski 1978). This individual was seen probing the upper flower stem of lanceleaf tickseed, Coreopsis lanceolata, during May of last year at Shaw Nature Reserve in east-central Missouri. I’m not sure how well the life history of this species is understood, but I did find one interesting record of twelve individuals feeding gregariously on a dead chicken (Engelhardt 1912)! Apparently, feeding on carrion and other extra-phytophagous foods such as bird droppings and dung is a not uncommon practice among the Coreidae and closely related Alydidae (Adler and Wheeler 1984).

I kind of lucked out with this shot – I’d just gotten my new camera two weeks earlier and can’t say I really knew what I was doing at this point. I had first noticed and photographed the bug sitting on top of the flower but totally blew the exposure due to the flower’s bright yellow color.  My clumsy approach also caused the insect to move under the flower, where I watched it settle down and begin feeding before trying another shot. The dorsal surface of this species is mottled gray and brown, allowing the bug to blend in with most backgrounds. The underside of the body, however, is thickly matted with white hair, providing a very nice contrast with the black background that I stumbled upon achieved in this photo to emphasize the distinctive appearance of this often-overlooked insect.

Photo Details: Canon 50D w/ 100mm macro lens (ISO 100, 1/250 sec, f/14), Canon MT-24EX flash (1/4 ratio), undiffused. Typical post-processing (levels, minor cropping, unsharp mask).

REFERENCES:

Adler, P. H. and A. G. Wheeler.  1984. Extra-phytophagous food sources of Hemiptera Heteroptera: Bird droppings, dung, and carrion.  Journal of the Kansas Entomological Society 57(1):21-27.

Engelhardt, G. P. 1912. A hemipteron on carrion.  Journalof the New York Entomological Society 20:294.

Slater, J. A. and R. M. Baranowski. 1978. How to Know the True Bugs. W. C. Brown Company Publishers, 256 pp.

Copyright © Ted C. MacRae 2010