Question 1

Explain your opinion on the discussion below:

When it came to selecting a biological control that worked, I decided to research Bacillus thuringiensis or known as BT. Bacillus thuringiensis is a soil borne organism the can be added to a plants soil to control larvae and/or microbial insects. The bacillus thuringiensis began to become popular in the 1950's. However, this biological control case was first seen in Japan 1901. A bacteriologist named Ishiwata had found a diseases silk worm colony that was the cause of BT. Now the way the BT works is that "the active toxin is generated in the insect gut after ingestion of the crystals, by solubilization and proteolytic activation of high molecular weight protoxin protein", as stated in Biocontrol of insects, pg 253. For instance, we all know when it comes to growing any type of plant there comes insects. The plant will attract larvae or microbial insects and they will want to feast on the plant to survive. Nonetheless, it will not be a problem once the bacillus thuringiensis (BT) is added to the plants soil. In result the insect/pest will ingest the plant that was grown with BT and die due to the toxic protein collapses the insects/pests' gut.

As for the biological control that didn't work I chose to research about the cane toads. The cane toads were first introduced in Australia in 1935. The toads were brought in to control beetles that were destroying and eating the sugar can fields. Once the toads were introduced to Australia they were helping by feasting on all the beetles in the sugar cane. But, this biological control failed because the toads didn't have a natural predator to control their numbers. Reason being is that once the toad becomes an adult it can produce venom on its skin to kill any animal that tries to eat it. So, that caused a problem for this biological control to fail due to the adult cane toad couldn't be killed. Also because of the large amounts of eggs they lay each year, causing them to spread throughout Australia.

Reference

Carlton, Bruce C., and Jos M. Gonzlez. "Biocontrol of Insects -." SpringerLink, Springer Netherlands, 1 Jan. 1986, https://link.springer.com/chapter/10.1007/978-94-009-4396-4_19.

"History of Bacillus Thuringiensis." Passel, https://passel2.unl.edu/view/lesson/488bc25cd8ff/5#:~:text=Bacillus%20thuringiensis%20(Bt)%20is%20a,by%20Ishiwata%2C%20a%20Japanese%20bacteriologist.

Environment, Department of the. "The Cane Toad (Bufo Marinus) - Fact Sheet." DCCEEW, 1 Jan. 1970, https://www.dcceew.gov.au/environment/invasive-species/publications/factsheet-cane-toad-bufo-marinus#:~:text=In%20February%202009%2C%20cane%20toads,coast%20of%20NSW%20in%202003.

Question 2

Explain your opinion on the discussion below:

The red water fern is an aquatic weed which is located in bodies of water in parts of South Africa. When the red water fern is uncontrolled it becomes quite the problem for the aquatic habitats and ecosystems. According to the article by McConnachie, A. J., Hill, M. P., & Byrne, M. J. (2004) the red water fern had rapidly spread throughout the waters of South Africa because it does not have many natural predators, it had been added and grown into the water by humans and by the flow of water, and if the water is rich in phosphorus this encourages the growth of red water fern. In 1997, a frond-feeding weevilStenopelmus rufinasuswas imported from Florida to aquatic regions of South Africa as a biological control to reduce the amounts of red water fern growth. This biological control has become one of the most successful cases in the world which accounted for a 81% decrease of the red water fern in 112 sites in South Africa.

Failed Biological Control: Gall fliesUrophora quadrifas- ciataFrfld.andU.affinis(Meig.)

One example of a failed biological control is when Gall flies were released into North America in the 1980s to reduce the population of diffuse Knapweed(Centaurea diffusaLam). This process was not entirely successful because the decrease of he diffuse knapweed was not sufficient enough. The knapweed continued to grow and the gall flies did not reduce its density.

Citations:

McConnachie, A. J., Hill, M. P., & Byrne, M. J. (2004). Field assessment of a frond-feeding weevil, a successful biological control agent of red waterfern, Azolla filiculoides, in southern Africa.Biological Control,29(3), 326-331. https://doi-org.ezproxy.umgc.edu/10.1016/j.biocontrol.2003.08.010

Harris, P. 1980a.Establishment ofUrophora affinisFrfld. andU. quadrifasciata(Meig.) in Canada for the biological control of diffuse and spotted knapweed. Zeit. fur ang. Entomol. 89: 504-514.

Question 3

Explain your opinion on the discussion below:

In the case the biological control worked, my research directed me to the Japanese beetle, scientifically known as Popillia japonica. Japanese beetle (Popillia japonica) is a pest that came from Northern Japan. It was first found in the United States in 1916, after being mistakenly introduced into New Jersey. It became a widespread and destructive pest of turf, landscape, and ornamental plants. This pest destroyed several fruits, gardens, and crops. Its destruction can go over a range of more than 300 plant species. The grown Japanese beetles feed on flowers, fruits, and foliage, whereas their larvae, commonly known as white grubs feed on the roots of grasses. Currently, the Japanese beetle is the most widespread pest of turf and grass. It costs the turf and ornamental industry approximately $450 million each year in management alone (Potter and Held 2002). When the beetles were first detected in the United States, they had no natural enemies and were able to grow unchecked. Starting in the 1920s, researchers began studying the Japanese beetle's natural enemies, looking for species that could be introduced to help control the U.S. population as biological control. They were at last controlled biologically by two species of tiphiids wasps which were Tiphia vernalis and Tiphia popilliavora. They have proven successful biological control agents against Japanese beetle grubs (Fleming 1976). Tiphia vernalis attacks overwintering grubs, while Tiphia popilliavora attacks young grubs in late summer.

As for the biological control that failed, I decided to do my research on cane toads, scientifically and currently called Rhinella marina. In June 1935, the Bureau of Sugar Experiment Stations introduced cane toads (Rhinella marina) from Hawaii to Australia. They were introduced as a biological control method against the Greyback beetle (Dermolepida albohirtum) that was destroying sugar cane crops. They were introduced in the hope that they would control populations of cane beetles that were damaging the sugar cane industry. Afterward, these cane toads were bred, and a large number of their offspring were released in sugar plantations of coastal Queensland over the next year (Turvey, 2013). These toads were native to South and Central America and had been used successfully as a biological agent against cane beetles in Hawaii. Unfortunately, these toads quickly became pests. They later migrated rapidly poisoning native species. The experiment failed and was what they called a famous failure of a biological control. This particular case is a big disappointment. It is a case in which your best friend, who knows everything about you, starts fighting you and becomes your worst enemy.

References:

Japanese beetle. Japanese Beetle | National Invasive Species Information Center. (n.d.). Retrieved August 31, 2022, from https://www.invasivespeciesinfo.gov/terrestrial/invertebrates/japanese-beetle

point, A. this, & Each of the horticulturalists Emily Stine replied on July 26. (n.d.). Japanese beetle biological control release. Denver Botanic Gardens. Retrieved August 31, 2022, from https://www.botanicgardens.org/blog/japanese-beetle-biological-control-release

corporateName=National Museum of Australia; address=Lawson Crescent, A. P. (2022, May 3). Introduction of cane toads. National Museum of Australia. Retrieved August 31, 2022, from https://www.nma.gov.au/defining-moments/resources/introduction-of-cane-toads

Shine, R., Ward-Fear, G., & Brown, G. P. (2021, May 27). A famous failure: Why were cane toads an ineffective biocontrol in Australia? Macquarie University. Retrieved August 31, 2022, from https://researchers.mq.edu.au/en/publications/a-famous-failure-why-were-cane-toads-an-ineffective-biocontrol-in