What Insect Pheromone Glands Do

Pheromones are chemicals made and secreted by living things to send messages, usually to members of their own species. While popular culture makes the most of pheromones that send a mating message, many insects use pheromones to send a variety of messages. In the insect kingdom, insect pheromone glands are very useful to create signals that can communicate to a large community quickly, to communicate over several miles or to mark a specific area as protected or safe.

Many Messages

Pheromones can be left on a place to mark it or they can be released into the air to communicate with many members of an insect species at one time. When some types of insects are attacked by a predator, their insect pheromone glands release a substance to warn others. In aphids the message is to escape. In bees, the message is to swarm and attack.

In insect species in which the eggs are laid in separate places rather than in a hive or nest, the females have insect pheromone glands that mark their egg clutch to signal to other females that this spot is taken. This has been studied in insects that lay their eggs in plants that will provide food for the hatchlings. By warning other females away, all the egg-layers have a chance of providing enough food for their young.

Ants have insect pheromone glands that lay down a trail when food is found. The trail is made when they return from the food source to the nest. As other ants follow the trail, they release the same kind of pheromone to keep the trail fresh. When the food finally becomes used up, the ants stop traveling to it and the trail evaporates quickly. One species of ant has insect pheromone glands that will release a repellent chemical when the food source is used up.

Of course, insects also produce sex chemicals. Butterflies have insect pheromone glands that are able to release chemicals that can travel for more than six miles to attract prospective mates. Humans use the product of insect pheromone glands to send messages to pest insects. These chemicals can be used to monitor the insects, to create confusion or disrupt mating to control their populations. While the science of pheromones is still in its infancy, the study is making great advances. Once they are better understood, pheromones will be useful in understanding and directing the world of insects and other species.