Warm temperatures and abundant rainfall year round make the lowland 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 and plant debris would soon bury the jungle were it not for the another group of plant eaters, the termites.
Sometimes termite nests are found in trees.
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! 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.
Dark trails mark the foraging routes of termites on tree trunks as they search for food.
Termites are part of an elite group of social insects that include the army ants and leaf cutter ants we met in the two previous episodes of Bug of the Week. 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. 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.
The termite soldier squirts defensive chemicals at enemies through the elongated snout on its head.
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 hole to defend the colony. In some species of termites, soldiers are armed with jaws that stab, cut, or snap and whack an enemy. 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. From this snout, called a 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 Belizean guide invited us to sample the termites to learn why so many other insects, birds, and mammals seek a termite buffet. While I found the delicate flavor reminiscent of carrots Julienne, 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 web site.