Morgan Oberweiser introducing animal sound activities to junior explorer club
The Adams Ant Lab hosted elementary school children from the Junior Explorer Club of Upper Arlington. Recent graduate Mazie Davis and undergraduate students Andrew Mularo and Morgan Oberweiser put together a program to teach the little ones about various ways that animals communicate. First the students played a bioacoustics guessing game – they listened to some diverse audio recordings, courtesy of the Borror Lab of Bioacoustics, and tried to guess what animals they came from.
Can you tell which animals make these sounds? Look for the correct answers at the bottom of this post.
mystery sound 1:
mystery sound 2:
mystery sound 3:
Next the students learned about the use of coloration for communication. They observed camouflage in northern walking stick insects and African ghost mantises, as well as warning coloration in Peruvian black velvet stick insects and yellow banded poison dart frogs.
Northern walking stick insect
yellow banded poison dart frogs
The last animal communication system we discussed was chemical communication. The students played a game in which they were each given a scented cotton ball (peppermint, almond, vanilla) and were tasked with sorting themselves into groups using only their noses. Then they compared their skills to those of our large Atta ant colony.
Ant colonies & fungus gardens
The grand finale of the trip was a quick tour of the tetrapod collection lead by Dr. Katherine O’Brien. It was a joy to have such wonderful and inquisitive kids come to visit – we expect to see many of their excited faces return come next spring’s Open House (April 7, 2018)!
About the Author: Morgan Oberweiser is an undergraduate (Evolution and Ecology major) research assistant in Rachelle Adams‘ lab.
Answers to animal sound quiz: sound 1 = American alligator (chickadees scolding the alligator), sound 2 = Texas leafcutting ant, sound 3 = South American catfish
To date, around 71% of all described ant species have been found to sting or spray secretions from their venom glands. Some spray acid such as Formica mound building ants (clip from Life in the Undergrowth – Supersocieties by David Attenborough):
while others inject venom like the red imported fire ant Solenopsis invicta (video by Brave Wilderness channel):
Still other species wipe or paint their victim with poison and can dispense it like a smelly gas into the air. The toxic cocktail of organic compounds that make up ant venom is diverse. The venom of some species contains peptides and proteins, but these molecules typically only constitute 0.1-5% of the total venom extract. Instead, many species of ants depend upon alkaloids, a group of organic compounds defined by a heterocyclic ring containing a nitrogen atom. First discovered in ants in 1970, a diversity of venom alkaloids has been found throughout the subfamily Myrmicinae, with six structural classes represented and various differences in the substituents or side chains attached to the main molecule.
Why study ant venom?
Venoms have been found throughout all major animal phyla and play important roles in a number of ecological interactions, especially in predator-prey relationships where they are used as offensive or defensive chemical weaponry. While the venom alkaloids of many ant species have been identified and characterized, the biological activities of these compounds have only been investigated in a minority of groups. Alkaloids are presently known to have adverse toxic effects on a range of organisms; for example, the major component of S. invicta venom has not only been shown to act as a toxin on predatory and prey animal taxa but also possesses herbicidal and antimicrobial properties. Additionally, some alkaloids have been demonstrated to be utilized in a non-toxic capacity and serve communicative functions as well.
One of the goals of the Adams Lab here at OSU is to understand the biological functions and properties of the various venomous alkaloids of ants, and an area of active research has been within the genus Megalomyrmex. Although the majority of species are free-living predators, some are social parasites that infiltrate the colonies of fungus-farming ants. They consume host brood and fungus garden by dominating the farmers with their alkaloidal weaponry. A well-documented example of this interspecific interaction has been between the parasitic Megalomyrmex symmetochus and its host Sericomyrmex amabilis, in which the venom of M. symmetochus is a crucial component in the aggressive interactions that take place throughout the establishment and maintenance of the host-parasite relationship.
During these aggressive interactions, M. symmetochus ants often use three main types of alkaloid dispensing behaviors: gaster flagging, side-swipe sting, and gaster-tuck sting.
A) Gaster flagging is when M. symmetochus ants vibrate their gaster at approximately a 45-degree angle with a drop of alkaloid venom at the tip. This allows for the venom to be dispersed into the air at a low concentration, and is thought to be a warning to their host ants to deter them from attacking, acting as both a visual and chemical signal.
B) Side-swipe sting is when M. symmetochus’ gaster is waved from the side towards the host, dispensing the venom directly onto the host ant.
C) Gaster-tuck sting is when the gaster is tucked under the body in between the legs towards the host ant, dispensing venom directly onto the host (see illustrations below for a visual representation of these behaviors).
However, the interactions between these species are not always aggressive, and in some cases the M. symmetochus parasites act like mercenaries and protect their host from a more lethal ant species – watch them in action (video by Rachelle Adams, Assistant Professor in the OSU department of EEOBiology):
Our future research will continue exploring ant venoms in a broader context. The Adams Lab will be traveling to Panama to collect and observe Megalomyrmex species in their natural habitats as well as conduct experiments to gain greater insight into their biology. Look for our future blogs from Gamboa, Panama at the Smithsonian Tropical Research Institute in May!
Acknowledgements: We would like to thank Rozlyn E. Haley for the ant illustrations.
Reference: Adams, R. M., Liberti, J., Illum, A. A., Jones, T. H., Nash, D. R., & Boomsma, J. J. (2013). Chemically armed mercenary ants protect fungus-farming societies. Proceedings of the National Academy of Sciences, 110(39), 15752-15757.
About the Authors:Conor Hogan is a graduate student in Rachelle Adams’ lab and Mazie Davis is an undergraduate student who did a research project on parasitic ant stinging behaviors in Rachelle Adams’ lab in 2016.
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