350 million years ago, the first insects appeared, and they now have adapted to nearly every habitat on earth. The class Insecta is the largest and most familiar class in the Phylum Arthropoda. Containing over a million species that are grouped in 34 orders, the Insecta Class is massive. There are 90,000-100,000 species known in North America alone. When looking at the structure of insects, you will immediately notice segmented bodies and the exoskeleton (hard covering). The difference between the Insecta Class and most Anthropods are there three distinct body regions: head, thorax, and abdomen. The head bears the mouthparts, eyes, and antennae. The insect thorax of adults has three pairs of legs and two pairs of wings, although the amount of legs and wings does vary by insect. The abdomen of an insect is comprised of six to ten segments, including the terminal structures of cerci, ovipositor, and the aedeagus.
The ant is within the Kingdom Animalia, Phylum Anthropod, Class Insecta, Order Hymenoptera, and Family Formicidae. With over 12,400 species of ants, they are all throughout the world. Ants commonly nest in soil close to food sources. Some live in colonies in underground tunnels or in galleries in dead wood. They usually can be found near sidewalks, buildings, or other locations with a high population of people. Sometimes, winged males and females emerge from the nest and perform a brief mating flight. After mating, the males die, and the females lose their wings and return to the ground to start a new colony. Worker ants gather food, maintain and defend the nest, and tend eggs, larvae and pupae. Selection of food differs among species but may include fruits, seeds, nuts, dead or live insects, dead animals, and sweets. After a newly mated queen establishes a new colony and weeks or months underground, she will begin to lay her eggs. The eggs hatch and then she feeds the white, legless larvae with her own wing muscles and fat bodies until the larvae pupate. The pupae transform into sterile female adult workers several weeks later. The first workers dig their way out of the nest to collect food for themselves and the queen while she continues to lay eggs. The workers continue to add new chambers and galleries in the nest while the population increases. When a few years go by, the colony will produce winged male and female ants that leave the nest to mate and form new colonies.
Ants are beneficial insects that provide many advantages for the environment. By building nests and colonies, they are reducing soil compaction and helping aerate the soil. Many of these insects are omnivorous and will eat just about anything. The fire ant species has been shown to decrease some pest populations. Arthropods such as ticks and mites are eaten and can be wiped out by a mound of fire ants. They have been known to reduce populations of chiggers and prey on flea larvae and hatching cockroaches. Ants also eat boll weevils, caterpillars, and other pests that provide a huge burden on cotton and sugarcane growers. Many farmers rely on ants to minimize the amount of insecticide they have apply on their crops.
The Bark Beetle belongs to the Kingdom Animalia, Phylum Anthropod, Class Insecta, Order Coleoptera, and Family Scolytidae. The Bark Beetle is considered a harmful insect with over 600 species in the United States and Canada. These beetles are as small as a grain of rice with a hard red, brown, or black cylindrical body. They are rounded sharply at front of thorax and behind elytra while being concave below at rear of the abdomen. The Male’s abdomen usually has blunt spines below, pointing to rear. They live in deciduous and mixed forests throughout North America. Each species attacks different types of trees and at different locations on the tree. The inner bark of various types of trees, including hickory, pecan, walnut, and Douglas fir is their food. In the early spring, females cut holes for eggs in the bark of dying or dead trees and deposits each egg in a separate side tunnel of the inner bark. The larvae bore deeper overwinter and pupate in the second summer. Adults emerge during the late summer or fall.
When you pull off a portion of the infested bark, you will find a winding pattern of the beetle and tunnels chewed by adults and larvae. The beetles mine the inner bark at different locations on a tree: twigs, branches, or trunks of trees and shrubs. Small emergence holes in the bark are a sign that the beetles were present. When a tree is weakened by an environmental factor such as drought, disease, or injuries, the Bark Beetle is more likely to be nearby. The European Elm Bark Beetle carries a fungus that causes Dutch elm disease. The Hickory Bark Beetle attacks hickory, pecan, and butternut trees throughout the eastern United States. The Fir Engraver feeds on fir trees along the Pacific Coast to British Columbia. Trees commonly begin to decline when attacked by Bark Beetles and can lead to the death of trees. When carving elaborate tunnels in the inner bark or wood of trees, the beetles are benefiting but the trees are being harmed.
- Beneficial Effects of Fire Ants. (2013, November). Retrieved October, 18, from https://articles.extension.org/pages/11184/beneficial-effects-of-fire-ants
- Rust, M., & Chloe, D. (2012, November). How to Manage Pests. Retrieved October 15, 2018, from http://ipm.ucanr.edu/PMG/PESTNOTES/pn7411.html
- Douce, G. (2018, August). Pine Bark Beetles. Retrieved October 18, 2018, from https://www.barkbeetles.org/pbb/pbbrecognize.html
- Seybold, S., Paine, T., & Dreistadt, S. (2008, November). How to Manage Pests. Retrieved October 20, 2018, from http://ipm.ucanr.edu/PMG/PESTNOTES/pn7421.html