Mimicry: Being Masters of Disguise

Invasive Pests are the Best!

We chose to do our blog post over the topic of invasive species. The first question that might arise is what exactly qualifies an insect species to be considered “invasive”. The U.S Forest Service defines an invasive species as one that is both nonnative to the ecosystem in which it is found and capable of causing environmental, economic, or human harm (U.S Forest Service, 2015). Invasive species often compete so successfully in new ecosystems that they displace native species and disrupt important ecosystem processes. We have discussed a few invasive species in class already, but there are hundreds of other species out there in the world today that are already causing much harm to agriculture and the environment around them.

One specific species of invasive insects that we have already talked a little about in class is the Colorado potato beetle (Leptinotarsa decemlineata), also known as the Colorado beetle, the ten-striped spearman, the ten-lined potato beetle or the potato bug. This insect gets its name from its choice of food, which is the potato plant. The beetle is native to America and Mexico and is present in all States of America except Alaska, California, Hawaii, and Nevada. It now has a wide distribution across Europe and Asia. Researchers aren’t necessarily sure how this beetle found its way into the northern and eastern parts of the Americas, or how it made its way into Europe and Asia for that matter.  The leading theories are that large wind gusts carried these insects into the Americas. The Colorado beetle was first documented in the U.K. at the Liverpool docks aboard shipped cargo, so this would explain how the beetle found its way into the European countries, then eventually traveled its way more east into Asian countries.

This small beetle poses a pretty big problem for potato farmers, and has even been the cause of some serious famines in the U.K. around the time of World War II effectively wiping out whole potato fields. Records of this insect being a major destructive pest to potato crops date all the way back to the 1840s. The large scale use of insecticides in agricultural crops effectively controlled the pest until it became resistant to the chemicals present in the 1950’s. Other pesticides have since been used but the insect has, over time, developed resistance to them all.  The Arthropod Resistance Database records that the species as a whole has evolved resistance to 56 chemical insecticides (Wikipedia, 2017). There is even reports from Ukraine in the 1970s of a strain resistant to hydrogen cyanide!

Wood boring insects are among one of the most hard to combat among pests. These insects can be harmful to fruit and nut producing trees and compromise the integrity of many types of lumber. Although some lumber damaged by boring insects is preferred for its original and rustic appeal, known as wormwood, in most cases a wood borer is bad news. A while ago I watched a movie starring Sandra Bullock called “Practical Magic.” In the movie, the main character’s mother heard the peculiar sound of the deathwatch beetle and mysteriously died less than a week after hearing the sound. This beetle, has ever since intrigued me because of the strange myth behind the noise it makes, which inspired its name. It is said that whoever hears the sound of the deathwatch beetle, someone is surely to die soon. This beetle also shows up in Mark Twain’s “The Adventures of Tom Sawyer.” In many countries, this insect is seen as a harbinger of death. The deathwatch beetle (Xestobium rufovillosum) is in fact a wood boring beetle and it makes its eerie noise by striking the vertex of its head against its pronotum in the dead of night. This is used mainly as a mating call, which is even creepier. This insects are brown, mottled with a greyish gold or green on their exoskeleton. They don’t cause as much damage as individuals, but over time in large numbers can be quite destructive to older wooden structures. The grubs of these beetles live inside the timber and emerge as adults that are usually around 7 mm long. These insects are mainly seen as a pest and can be found in certain types of old-fashioned furniture, barns, and country houses. These beetles tend to stay away from modern wood, as it is treated with certain chemicals to help keep out insects. In the case of an infestation of these quirky little animals, you should contact a professional pest control agency, lest those stories and myths become true.

The Asian Longhorned beetle kills a wide variety of trees throughout the U.S., and if so happened to spread amongst the country, they would kill thirty percent of all urban trees. They are home to China, Korea, and Japan. The longhorned beetle has a long black body with white spots,long antennas, and six legs.

Longhorned beetles are a threat to forest covering approximately forty eight millions acres. Killing hardwood trees like maples, willows, and birches. The forest protect public drinking water and are damaging homes for other species. Not to forget the billions of dollars worth of resources decreasing. The reproduction rate of the beetle is an average generation per year. Laying 30-70 eggs that hatch in 10-15 days. While feeding on bark, they leave large exit holes about half an inch in branches. In Oklahoma, they are commonly confused with the cottonwood borer. The difference between the two is the white, rounded rings around the antennae of the asian longhorn beetle, and also the bluish colored legs. Meanwhile, we have still not found a cure to stop these invasive species, but have found a way to slow down the spreading by treatment on the healthy trees before becoming prey to these beetles.

Contributors: Tyler Souza, Regina Davis, Malik Mason

References:

• Pacific Northwest Research. "Pacific Northwest Research Station." Invasive Species. US Forest Service, 29 Apr. 2015. Web. 22 Mar. 2017.

<https://www.fs.fed.us/pnw/invasives/>

• "Colorado Potato Beetle." Wikipedia. Wikimedia Foundation, 20 Mar. 2017. Web. 22 Mar. 2017. <https://en.wikipedia.org/wiki/Colorado_potato_beetle>
• Association, British Pest Control. "Death Watch Beetle." Death Watch Beetle - Death Watch Beetle. N.p., n.d. Web. 22 Mar. 2017.
• Klots, Alexander Barrett, and Elsie Broughton. Klots. Insects of North America. New York: Doubleday, 1971. Print.
• Service, Purdue News. "Check Trees Now for Asian Longhorned Beetle." Check Trees Now for Asian Longhorned Beetle - Purdue University. N.p., 19 Aug. 2016. Web. 23 Mar. 2017.
• "Asian Longhorned Beetle." Asian Longhorned Beetle. N.p., n.d. Web. 23 Mar. 2017.
• "The Nature Conservancy." Asian Longhorned Beetle | The Nature Conservancy. N.p., 17 Feb. 2017. Web. 23 Mar. 2017.