Mastotermes is the most primitive of termites, sharing characteristics with the Cryptocercus wood roaches, social cockroaches that share a common ancestor with all termites. Several extinct species of Mastotermes are known from the fossil record. Many extinctions are relatively recent, occurring several million years ago. The northern Australian species, Mastotermes darwiniensis, is the only extant species.
Like Cryptocercus, Mastotermes makes nests by chewing galleries in wood. Colonies are usually small but under ideal conditions may produce millions of individuals. A colony typically inhabits a single piece of wood but will forage on plant material outside the nest and may connect several pieces of wood with galleries. This type of nest places foragers closer to their sources of food. In some regions of Australia, Mastotermes makes vegetable production unprofitable due to extensive foraging Mastotermes colonies can kill a tree by girdling it at its base. The colony then builds a nest in the center of the dead tree.
Carpenter Ant Nest
Ants and termites both build nests. The nests must house a queen and the many attendant workers and brood. The general structure of the nest, chambers connected by tunnels, is similar due to the similar needs of social insect colonies. The most notable difference between ant and termite nests is that termites construct portions of the nest, most ant species do not. Ants primarily excavate soil with no other construction. However, in some cases ants will construct a lining for their nest. Ant mounds can be a meter in height and quite extensive. Although impressive, they are the product of soil deposition rather than directed construction.
Some termite species build structures above ground that are several meters high. These structures are not the products of soil excavation but a mixuture of termite saliva, feces and soil particles. Most termite species create pillars for structural support within their nests. Even those few species that do not construct pillars will create a lining for the nest. Termites that tunnel in wood may construct protective structures such as mud tubes that allow termite foragers to access water in relative safety.
Termite and ant nests are the result of independent evolution in two groups that arrived at a similar social condition by separate paths. Comparing the structures of termites and ants can give insights into the constraints how the solutions to similar problems evolved.
Mosquito larvae are aquatic, but have never adapted to breathing underwater. Instead, mosquito larvae must come to the surface of the water to breathe oxygen. Mosquito larvae have an extensions of their hindgut called anal papillae. The anal papillae form a tube that protrudes above the surface of the water when creating. Hairs at the end of the tube lay on the surface of water where they repel and prevent water from entering the tube.
The anal papillae have another function, absorption of salts from dilute fresh water. The salt concentration within a mosquito larva is higher than the salt concentration in fresh water. The anal papillae are involved in transporting salts against a concentration gradient. The anal papillae exchange protons and waste ammonia for other cations that are necessary for mosquito growth and development.
Photo: Ben Alkire
It is still winter in Indiana with snow on the ground but Spring will be here soon. Many gardeners bring plants indoors for the winter and set them outside during the summer. The outdoor plants can have insects on them and can lead to surprises. A friend sent me this picture of a Pipevine Swallowtail that emerged in his house in March. It is too cold to release outside it is unlikely to live long enough to find a mate in late spring. Last Fall, the house plants were resting in a garden near garden rue, a host plant for Pipevine Swallowtails. The fully developed caterpillar likely left the rue and pupated on one the plants that was brought indoors. Swallowtails enter diapause that does not break until both temperatures warm and daylight increases. Those conditions were obviously met for this butterfly. Some insect surprises are not as pleasant as this one.
One animal’s refuse is another animal’s resource. The yellow-spined bamboo locust, Ceracris kiangsu, has been observed drinking from puddles of human urine. Human urine contains nitrogen waste in the form of urea and excess salts. The locusts drink the urine to obtain nitrogen and salt. However, the locusts are unable to use urea as a source and urea is repellent. Why do the locusts drink urine?
When the urine is heated by sunlight on hot summer days, the urea is converted to ammonium bicarbonate with the help of microorganisms. The locusts are able to use ammonium bicarbonate to synthesize amino acids and ammonium bicarbonate has proved to be an attractant. Thus, the locusts will not drink fresh urine. They only drink after it is baked in the sun and the urea converted to ammonium bicarbonate.
Moebius Strip I I
Humans are social animals with social rules governed by a malleable culture. Obedience to norms and rules is optional. People who think they have the best rules spend their time trying to convince others to follow their rules. Animals, including insects, have often been used to teach moral lessons to human society. Social insects, such as ants are lauded for the relentless hard work, their foresight for storing food to survive winter, obeying their “ruler” and their cooperative spirit. However, comprehensive study of ants finds these character traits are not as true as popularly believed. Lectures by scientists often result in fingers in ears and people clinging to beliefs. Comedians may have more success, but not much. Leave it to American humorist Mark Twain to try to disabuse people of false notions about insects. In A Tramp Abroad, Mark Twain writes:
Science has recently discovered that the ant does not lay up anything for winter use. This will knock him out of literature, to some extent. He does not work, except when people are looking, and only then when the observer has a green, naturalistic look, and seems to be taking notes. This amounts to deception, and will injure him for the Sunday schools. He has not judgment enough to know what is good to eat from what isn’t. This amounts to ignorance, and will impair the world’s respect for him. He cannot stroll around a stump and find his way home again. This amounts to idiocy, and once the damaging fact is established, thoughtful people will cease to look up to him, the sentimental will cease to fondle him. His vaunted industry is but a vanity and of no effect, since he never gets home with anything he starts with. This disposes of the last remnant of his reputation and wholly destroys his main usefulness as a moral agent, since it will make the sluggard hesitate to go to him any more. It is strange beyond comprehension, that so manifest a humbug as the ant has been able to fool so many nations and keep it up so many ages without being found out.
Underside of Immature Bed Bug
An alert teacher at Luzerne County High School in Pennsylvania found a bed bug and reported it to the administration. The students were moved to another room so the room could be inspected. Rumors of bed bugs at the high school quickly spread inducing panic among parents who took their children home from school early. A further inspection of the school found no more bed bugs. The one bed bug likely traveled to the school in a backpack of a student or other type of bag.
The school superintendent says the panic reaction is overblown. Is he correct? Bed bugs are nocturnal and primarily move at night. They are unlikely to leave their harborage during the day. Since the students are only present during the day when lights are bright, the likelihood of a student bringing home an infestation is quite low. Additionally, the school was inspected and treated to eliminate bed bugs as a precaution. The missed class time is harmful to students and disruptive of the school. The administration wants the students to return immediately and threatened to punish students who stayed home due to the bed bug panic.
The unreported question: How did the bed bug get to school? It most likely came with a student or employee of the school. That person probably has a substantial infestation that needs elimination. Finding the source of the bed bug infestation and eliminating it would be most helpful to prevent future bed bugs at the school. Bed bugs are a public health problem and if treated as such, can be greatly reduced or eliminated locally. Treating bed bug infestations as a sign of a personal failure of poor housekeeping or bad sanitation is counterproductive.