NATURE NOTES - Number 21 May 28, 2021
Our current topic: Insects
Small critters, but huge numbers. Estimates as to the number of species of insects in the world vary greatly, but they all approach a million, with over 90,000 in the U.S. and Canada alone – and 450 of those are different species of Ladybugs! Some scientists claim 80% of all plant and animal species known to man are insects. You should not have trouble finding subjects to view. Maybe we can’t expect scouts to identify large numbers of species, but we can expose them to this fascinating part of nature. Insect Study, Nature and Forestry Merit Badges all require the scout to address insects. First, what is an insect? Insects are invertebrates, meaning they have no backbone, but have an exoskeleton, or type of shell to protect them. An insect must have: 3 pair of jointed legs; three major body segments (head, thorax and abdomen); usually antennae; usually two pairs of wings; and some specific mouth parts difficult to see without magnification. Not always terribly exact. Nature loves to throw in an exception here and there.
In the class Insecta there are about 30 sub-groups, or “orders” of insects, each with distinguishing characteristics. It’s not too difficult to start placing insects in some of the more common orders. For example, butterflies and moths are in the order Lepidoptera. All beetles are Coleoptera. Wasps, ants and bees are Hymenoptera. A good insect field guide can provide information on these orders and help a scout identify what he/she might have collected. Specific species identification is difficult, so stopping at the order may be sufficient. Just stepping into this discussion about the complex and diverse world of insects might excite a scout enough to pursue this much deeper.
Scouts have learned in school that insects pass through 4 stages of life: eggs, larvae, pupa, and adult. That’s correct - sometimes. Other insects skip the larvae or pupa stage and go into nymphs, or tiny, immature adults. Ever seen a little grasshopper or a tiny praying mantis? They are moving through nymph stages on the way to becoming an adult. Once an adult, some insects, like some butterflies, don’t eat. They live a very short time and die. They have laid their eggs to continue the cycle, and their job is done. Note that some insects are great at camouflage. It helps them survive their many predators. Some insects have markings to scare away predators, or they look like some other insect that is toxic to a predator. There are many opportunities with insects to show how nature protects its creatures. Many of these protections don’t work real well, and most insects don’t survive long. That’s why so many of them start out in the egg stage – sometimes millions of them. When you are likely to get eaten at a young age, you need lots of siblings to continue the species. Note that elephants don’t have many offspring.
A question you can ask scouts to start an interesting discussion is: are insects good or bad? The answer is: Yes. Insects pollinate plants that produce our food and the food for many animals; some insects prey on other insects to control populations; insects are a major food source for birds and other animals; they decompose organic matter and help return elements to the soil. They also carry diseases, destroy crops and trees, eat your house, sting you, bite you and can cause general human displeasure. Make scouts think about the good and bad of nature. It’s complicated. Regardless, insects are an important and fascinating part of nature and society. Scientists who study insects are called entomologists, and many specialize in a certain area, such as crop insects, forest entomology, control of insect-born disease, etc. Many, many mysteries in the insect world still are unsolved, so there’s lots of opportunity to learn.
Some scouts seem to be fascinated with bugs. Encourage that, but always urge CAUTION, as there are insects out there that can be harmful. If they want to collect them, lure the insect into a pill bottle or zip lock bag and then freeze it. The Insect Study Merit Badge Pamphlet or a field guide like Simon and Schuster’s Guide to INSECTS will give additional information on collecting insects. Another good, simple guide is National Geographic’s Pocket Guide of Insects of North America. Insects are going to be around for a while, and humans will have to deal with them, so the future for a scout interested in insects is wide open. Help them understand that there are lots going on with insects - and nature.