Do you know what the word entomopathogenic means? Do you know any organisms that would be considered emtomopathogenic? In this lesson you will learn the meaning of this word as well as some examples of organisms that can be described as such.
A Suspicious Growth
Your mom is so excited about the state fair. Every year she puts so much work into growing her tomatoes.The gardener with the largest and all-around best fruit or vegetable wins the green thumb award. Your mom has been nervously caring for her plants all season and she has some very good tomatoes indeed. One day while helping your mom in her garden, you notice what looks like a fuzzy growth on a few of her plants. You mom doesn’t seem to think it’s a big deal, but you tell her that the growths look like images you saw in class while learning about entomopathogenic bacteria.
You urge you mom to harvest her most prized tomatoes so they won’t be destroyed before the fair. Your mom refuses until you tell her what ‘entomopathogenic’ means and how this can hurt her chances of winning the green thumb award. You both make your way to the computer to look up more detailed information and to see if your suspicions are correct.
As you and your mom comb through information, you see something online that explains the term entomopathogenic. Look mom, you say, this website says that the prefix entomo means ‘insect’ and the word pathogenic means ‘disease.’ Insect disease? You and your mom go back outside and take a look at her tomatoes and realize that the fuzz is moving! It is not attached to the tomato at all; it was attached to an insect that was trying to eat the tomato. Your mother’s plants are safe! That’s a relief.
However, you and your mom still want to learn more about entomopathogenic organisms.As you read you realize that their are many types of organisms that are considered to be entomopathogenic. Entomopathogenic organisms are parasitic organisms that grow on or in insects, most often killing them in the process.
The website that you are reading highlights three types of entomopathogenic organisms: fungi, nematodes, and bacteria. Not all nematodes, fungi and bacteria are insect parasites, but some specific ones are.
Entomopathogenic fungi most often infect the insect through contact with its outer covering or by ingestion. Once the fungus has made contact with the insect, it begins to grow and divert resources from the insect to itself. It eventually will kill the insect. As the insect is suffering from this infection it may change its eating and mating behaviors.
The insect may also behave in a hurried or odd manner. Examples of entomopathogenic fungi are Beauveria bassiana, which infects silk worms, and Lagenidium giganteum, which infects mosquito larvae.
Some examples of entomopathogenic nematodes are Steinernema and Heterorhabditis. These nematodes are host to bacteria in their digestive tract, forming a symbiotic relationship that is beneficial to both organisms. Once a host is located, the young nematodes infect it via its mouth, anus or any other thin-skinned body part.
Once inside, the bacteria in the nematodes’ gut emerge, multiply and rapidly kill the host. The young nematodes feast on the bacteria and the dying insect. As they feed, they develop into adults and produce offspring. The adults and new young nematodes burst from the dead insect to start the process all over in a new host.