The termite soldier squirts defensive chemicals at enemies through the elongated snout called a nasus on its head.
Having visited beautiful but deadly tiger moths and their colorful caterpillars in Florida in weeks past, this week we embark on a study abroad with students of BSCI 339M, Mayan Culture and the Interface Between Tropical Rainforests and Coral Reefs. Our first stop is the rainforest near the ancient Mayan ruin of Cahal Pech, in Mayan, the "Place of the Ticks."
Sometimes termite nests are found high in trees.
Warm temperatures and abundant rainfall make the rainforest of Belize one of the most productive ecosystems on the planet. Rapidly growing trees and shrubs provide a bounty of food for many plant-eating insects, reptiles, birds, and mammals. However, these vegetarians cannot devour the enormous quantity of plant material produced. Plant debris would soon bury the jungle were it not for work of another group of plant eaters, the termites.
Termites are remarkable creatures that consume both living and dead plant material. To utilize the nutrients tied up in plants, termites rely on symbiotic bacteria and, in some primitive species, protozoa, which inhabit their gut, to help digest the rugged plant material called cellulose. Termites have an unusual and rather crude way of passing these vital microbes from one termite to the next through a process known as proctodeal trophallaxis. One termite excretes a droplet of microbe-packed fluid from its anus. This packet of goodies is consumed by another termite waiting at the rear end. Yum!
Dark trails mark the foraging routes of termites on tree trunks as they search for food.
The transfer of liquids from one termite to the next is also a way of disseminating chemical messages called pheromones that regulate the development and behavior of termites within the colony. Termites are part of an elite group of social insects that include the ants and several wasps and bees. Social insects such as termites and ants have a distinct division of labor with a caste system that includes specialized workers, soldiers, and reproductives. Termite reproductives are called kings and queens. Queens produce thousands of eggs that hatch and develop into workers, soldiers, and new reproductives. Workers perform a variety of tasks including tending the young, feeding the queen and soldiers, and gathering food. Soldiers, as the name implies, provide protection for the colony, and there is some evidence that they also scout out food resources for the workers to gather.
Large termite nests like this one at the base of a tree contain thousands of termites.
Termites are not creatures of the light. They live in subterranean nests, inside trees and fallen logs, or they may build nests called termitaria composed of partially digested wood particles and excrement. During our Belizean adventure, we encountered several large, irregularly shaped, round or oval termitaria in trees. Radiating from these nests were tunnels of soil, wood, and excrement that enabled the termites to move across the forest floor and into nearby trees and shrubs to gather vegetation and bring it back to the nest to feed the brood and queen.
Soldiers of different termite species have unique adaptations for repelling enemies. Some soldiers are armed with jaws that stab, cut, or snap and whack an enemy. One of the students tested the resolve of a termite colony by breaching the nest with her hand. Soldiers from deep within rushed to the breach to defend the colony. The termite soldiers in the nest we disturbed were chemical warriors known as nasutes. These highly evolved termites have dark brown heads with a long, tubular snout, called a nasus. From this nasus, they squirt sticky defensive secretions that can entangle, irritate, and repel invading enemies such as ants. A hand or finger placed over the breach in the nest was soon coated with sticky liquid provided by the nozzle-headed soldiers.
A breach in the termite trail is instantly guarded by termite soldiers as they await repairs to be made by workers.
Termites are a favored food source for many forest creatures. A Belizean guide invited us to sample the termites to learn why so many insects, birds, and mammals seek a termite buffet. After plucking a few workers from the colony and savoring each morsel, I found the delicate flavor reminiscent of carrots Julienne. This assessment was not shared by all, and some of the students said the termites tasted, well, like bugs.
References
Two great books, "The Insect Societies" by E.O. Wilson, and “For Love of Insects” by T. Eisner, were used as references for this Bug of the Week.
For more information on tropical termites, please visit the following websites:
http://www.anywherecostarica.com/flora-fauna/invertebrates/arboreal-termites
http://www.pnas.org/content/78/3/1976.full.pdf
http://www.fcla.edu/FlaEnt/fe85p273.pdf
For general information on termite biology, please visit these websites: