One of the most exciting things to me about originally going to University was that they gave me an email address. This may sound superficial, but as a seventeen year old kid I felt like it was a qualifier. The email sbaynton@uoguelph.ca was an identifier to the fact that I had made it. No surprise then, I spent the next six years up to this point using it as my main email address, registering everything and anything to the tag.
Sadly, all things must come to an end, including school email adresses, and I was informed just this week that they would be shutting down the account. Boo. This means that while on shitty computers in Africa, I must arduously set out to remember and change every single thing that I have ever linked to it.
Rest in peace sbaynton@uoguelph.ca
The good news is that it isn't all bad news. I have never taken the time to delete anything in the past years, and thus rummageing through the old messages is comparable to a walk through time. One paticular thing I found was this paper below. Although it is by no means a great paper - it was written on a very terrible Mac computer while I was sitting in the middle of the Amazon Rainforest. The sheer act of finding it provided me with a swell of memories regarding good times. For that reason along with the fact that the observed behaviour was novel and 'freaking sweet', I decided it needed a little recognition. Thus, I will immortalize it here:
A Termitophilous Staphylindae of Amazonian Ecuador
Field Entomology ENVB*4260
Heather Cummings, Stephen Luk, Mark Merilo, Sean Baynton
Introduction
The word termitophile is used to describe any organism that has a special association with termites. This interaction usually involves the scavenging or stealing of food from the colony or direct feeding on the termites themselves. Termites however are not defenseless, as all species have specialized soldier castes for the protection of their mounds from predators and invaders. Therefore, in order to circumvent the natural defenses of the mound, termite associates must develop unique ways to avoid attack by colony defenders. A number of Coleoptera have been successful in accomplishing this, and among the most notable of these are rove beetles--members of the Staphylinidae, a family that is generally characterized by slender, fast, and voracious predators that actively hunt other insects. A few rove beetles have developed intimate relationships with termites, living a parasitic existence as termitophiles on mounds.
Certain Brazilian species of termitophilious staphylinids are known to release a mimic of the queen pheromone that disguises them as secondary reproductives, therefore deceiving soldiers into accepting them as nest mates (Kristner et al. 2000). Although there is no access to chromatography with which to assess the chemicals released by termitophilious rove beetles, we examine the relationship between a staphylinid and a species of mandibulate-nasute termite possessing both nozzle and mandibles that is believed to be of either the genus Armitermes or Rhynchotermes (Thorne, 2009). In particular we explore the normal defensive response of the termites to perceived predators, and the interaction between the staphylinid and termites from both the host colony and other colonies.
Methods
The selected mound was monitored at regular intervals over a three day period for the presence of termitophilious staphylinids. When an individual was observed, its position on the mound was recorded to determine whether it lived in the mound or elsewhere, and its natural behaviour was immediately documented to provide a reference point. Beetles were collected for use in controlled lab experiments. Large samples of nest from three different arboreal species, including the mandibulate-nasute host, were collected in sample containers and taken to lab for experimentation.
Control tests using ants were performed on site to determine the standard reaction of the three different termite colonies to a perceived threat. Ants were applied to a mass of termites from each colony, and the results were recorded. This was repeated several times with different types of ants, including common rainforest species of Cephalotes and Ectatomma.
Sample Staphylinid beetles were then placed into termite the nest containers for set time trials. The reaction of the termites in comparison to that of the ants was gauged and recorded.
Results
Beetles of study were never observed to be active during the day, but were found on the surface of the nest at night, where they tended to occur around disrupted sites, such as where the nest had been previously breached.
Responses of termite samples to ants were relatively uniform in nature. The mandibulate-nasute host termites immediately perceived ants as a threat and attacked immediately with their mandibles. They were particularly aggressive towards Cephalotes, presumably because the observed interaction was an encounter with a scout ant. The other two nest samples exhibited similar reactions to the presence of ants.
A Staphylinid placed in a container of host termites received no attention, and was able to walk over and near termites without eliciting any defensive behaviour. The beetle tended to burrow and move along the sides of the container. When placed in container containing non host termites, observed behaviour of the beetle and termites was much different in nature. The beetle displayed an avoidance response to all termites in the container, and attempted to run away from any individuals it encountered. Similarly, termites in those containers responded to the beetle by opening their mandibles in preparation for attack.
Discussion
Our observations revealed that the rove beetles were always present on the mound but were absent within the nest. This indicates that they are not inquilines, but rather live outside of the mound and predate termites at natural breaches that would be caused by falling trees and anteater activity. Beetles were observed near disrupted areas that had been recently repaired, or were in the process of being repaired, including breaches made during experimentation. Since inquilines would have no need to emerge to the surface to feed, it is unlikely that the beetles are of such a nature. Additionally, these Staphylinids are presumed to be nocturnal because they were only observed after nightfall. This habit, which is common to most Staphylinid species, allows the beetles to feed on the surface of the mound while avoiding detection by diurnal predators.
Tests of termite response to ants were very useful in helping to determine the basic responsiveness of the colony to an immediate threat. The very active responses to ant invaders rule out that the termites are naturally passive, and imply that the Staphylinids must in fact be actively disguising themselves among the termites. Our hypothesis was further supported by the tests of the responsiveness of different termite species to the presence of the beetle. Given that certain species of termites responded aggressively to the beetle and the host one did not, yet all species responded to ant, we can conclude that these Staphylinids have some method of masking their presence from the host colony.
The existence of staphylinid termitophiles does not in itself seem to be uncommon. In New Guinea, discoveries of three Staphylinid species with guest-host relations have been made as recently as 2005 (Bourguignon et al. 2007). Termites use pheromones for a variety of purposes, including trail marking and nest mate recognition (Rupf et al. 2008); therefore the Staphylinids may be able to safely associate with host nests without detection by mimicking reproductive pheromones.
Although this interaction between Staphylinid and termite is not exactly unique in nature it is still very fascinating. Since colony odours of termites are so specific, it is remarkable that these predators have been able to co-evolve with termites to effectively infiltrate their nests (Seevers 1957). Although the precise mechanism for the beetles camouflage is still unknown, it is evident that the Staphylinids we studies have evolved to be a specific termitophile on the termite colony.
Acknowledgments
We extend our thanks to the staff of the Yasuni Research Station for provisioning us with facilities from which to conduct our experiments, to Drs. Gard Otis and Stephen A. Marshall for making this trip possible, and again to Gard Otis for corresponding with his colleagues to provide us with additional information for our study. Thanks also to Barbara Thorne and Adam Brunke for responding to Gard in a timely fashion and making available their expertise on termites and Staphylinidae despite the brevity of this study.
References
Bourguignon, T., Pasteels, J. M., Roisin, Y. (2007) Taxonomy, distribution and host specificity of the termitophile tribe Trichopseniini (Coleoptera : Staphylinidae) in New Guinea and adjacent islands. INSECT SYSTEMATICS & EVOLUTION, vol.38, no.4, pp.405-425
Kistner, D. H. (2000) A New Genus and Species of a Queen Mimicking Termitophile From Brazil (Coleoptera: Staphylinidae). Sociobiology [Sociobiology]. Vol. 35, no. 1, pp. 191-195.
Rupf, T., Roisin Y. (2008) Coming out of the woods: do termites need a specializedworker caste to search for new food sources? Naturwissenschaften (2008) 95:811-819
Seevers C. H., (1957) A Monograph on the Termitophilous Staphylinidae (Coleoptera) Fieldiana: Zoology, Vol. 40
Thorne. B. (2009) Correspondence through email in regards to termites.
