Insects

The Greek translation of insect means cut into segments or segmented which is a good description of an

insect’s body. All insects have three body segments the head, thorax, and abdomen. Insects also have

three pairs of legs, six in total. Spiders, tics, and mites on the other hand have 4 pairs of legs or eight in

total. These members of the arachnid family are often confused as insects but they are not true insects.

Besides the 3 pairs of jointed legs, all insects have compound eyes, a pair of antennae, and a ridged

exoskeleton made of chitin, a relatively hard substance similar to the material that makes up our finger

nails. There are over 1 million species of insects found throughout the globe and nearly 80,000 species

of insects have been identified in our region. It is estimated that insects make up nearly 90% of the

known living creatures on the planet when you count sheer numbers. Most insects hatch from eggs and

exhibit either incomplete or complete metamorphosis. Incomplete metamorphosis means that the

juvenile often known as a nymph looks a lot like the adult. This juvenile goes through a series of molts

where they cast of their old exoskeleton then develop a new one as they grow a bit larger. The various

stages that an insect goes through before they become an adult is called an instar. Insects that display

complete metamorphosis arise as a grub like larvae from the egg, they go into an inactive pupal state

then they emerge as an adult looking much different than the larvae. Moths, butterflies, and beetles

exhibit complete metamorphism. Some insects can reproduce asexually without an egg. An example of

this are aphids. During the summer adult female aphids can give rise to all female aphids. In the fall

aphids mate and both male and female aphids are produced. Insects are found in all environments and

they walk, fly or swim to get around. Most insects live solitary lives but some like, bees, ants, and

terminates live in large well organized colonies. Insects come in all shapes and sizes and some are

native to this region having evolved in our area for thousands of years while others are recently

introduced from far off lands. These exotics normally enter this country from sea ports as a result of

global trade. Many of these new arrivals become serious pests because there are no native controls to

keep their populations in check. Insects can be harmful or beneficial to humans with some having both

qualities. Beneficial insects produce useful products such as honey, beeswax, and silk, they pollinate

crops, trees, and other plants, eat harmful insects, help decompose organic material, beautify the

landscape, and preform a number of other beneficial tasks that are not fully understood. Harmful

insects can spread disease, inflict painful or venomous bites, destroy crops, harm plant life, rot wood,

and be a general nuisance. The study of insects is called Entomology and it is a challenging pursuit

based on the sheer numbers of species present and the continual introduction of new species. Having a

working knowledge of insects is an important part of being a successful gardener, forester, arborist,

horticulturist, nurseryman, orchardist etc.


Insects can have a profound effect on the health and vigor of individual trees and forests. Oftentimes

insects are characterized by their method of feeding when describing the damage they inflict on trees

and shrubs. Insects can damage trees by piercing and sucking plant fluids, chewing up the leaf or other

plant part, or boring into the plant. There are a number of insects that damage trees by one of these


three methods found in this region. Future columns will focus on some of the insects that impact our

local trees and shrubs.