Insects are the largest and most diverse group of organisms on Earth. There are approximately 30 orders with the number of described species reaching nearly 1 million. However, some scientists believe the actual number may exceed 20 million! These phenomenal creatures constitute about 75% of all described animal species and are incredibly abundant, yet abundantly overlooked. Insects are found on land, in water and in air in nearly all habitats and all continents including Antarctica.
Like amphibians, insect species richness is greatest in tropical latitudes. Likewise, insect species richness is immense in the Neotropics though the actual number of described species remains uncertain at this point. Ecuador too, being among the 17 “megadiverse” countries, can boast of a tremendous inventory of insect taxa.
But what IS an insect? Quite often we here the term “bug” used as a catch-all for all sorts of invertebrate animals…. most of them being distinctly not actual bugs, creating much confusion. Insects are found in the Phylum Arthropoda. “Arthropods” are invertebrates with segmented bodies, jointed appendages and chitinous exoskeletons. In addition to insects, arthropods include spiders, centipedes, millipedes, scorpions, mites, lobsters, and crabs. Insects are the largest group of arthropods but can be distinguished from other arthropods by certain characteristics. Insects have three body regions (head, thorax and abdomen), three pairs of legs and a pair of antennae. One gift most insects have that other arthropods lack is the ability to fly.
When it comes to sex, mammals and other vertebrates are predictable compared to insects. Many insects are oviparous (deposition of an egg external to the female’s body) yet some are viviparous (where no egg is involved) and give live birth. Some insects even reproduce by parthenogenesis (where no males exist). Surprisingly, attentive parental care actually occurs in some species.
But are insects really important or just annoying picnic guests? To answer this question, first consider the number of described insects. Such a large, diverse group should suggest that ecosystems are extremely complex. Consequently, insects fulfill many important roles in these ecosystems. Many are herbivores while others function as predators feeding on other insects and other arthropods and even some vertebrates. A number of species are parasitic of vertebrate hosts while others are parasitoids in which females lay eggs on other arthropods that ultimately consume the host. Their roles as pollinators cannot be underestimated. Many taxa function as scavengers and detritivors (decomposers), and many more have important jobs within their ecosystems that we have yet to even discover! What then would happen if even one species of insect was removed from its ecosystem?
Perspectives about insects are quite varied. They are shunned and feared in some societies yet revered in others. It is true that some insects compete with humans for food, particularly in agricultural settings, and many are vectors of serious disease pathogens. However, we must consider their overall value in any given ecosystem with which they are members. Conservation and understanding of this group is equally critical if ecosystems are to function. Plus, they’re just darn cool!
Did You Know?
Snakes like boas and rattlesnakes have heat sensing organs on their faces to detect warm-blooded prey.
Beetles (Order Coleoptera) constitute the largest group of animals in the entire Animal Kingdom. Some 400,000 species have been described.
Many salamanders have no lungs at all and rely on breathing completely through their skin.
The word “bug” actually refers to a specific group of insects that include bedbugs, cicadas, leafhoppers and aphids. To prevent confusion, these creatures are sometimes known as “true bugs”.
Even though reptiles and amphibians are sometimes called “cold-blooded” they actually get heat from their surroundings and can be a lot warmer than so-called “warm-blooded” animals like mammals and birds.
The most toxic animal on earth, the golden poison frog, was once used to coat poison darts by indigenous peoples in what is now Colombia. A single frog holds enough toxin to kill 20,000 mice!
Toxin from a poison frog is now being used to develop a powerful new pain-reliever.
Gila monster venom was used to create perhaps the best treatment for diabetes available today.