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Are Joro Spiders Going to Kill Us All?

November 26, 2024

 

If you live in Atlanta, there’s a large chance you’ve come into contact with the now common Joro Spider. Measuring in at 3 inches long, Joro spiders have neon-yellow abdomens and long legs with bright yellow stripes. They build incredibly large and intricate webs and have seemingly positioned themselves as a super predator of arachnid world, catching basically any insect foolish enough to get caught in their web.

Joro spiders are native to East Asia and were first introduced to Georgia in 2013. Since then, their populations have been increasing, but still remain mostly confined to North Georgia and Southern Tennessee. These spiders have begun to dominate northern Georgia, setting up shop in forests and urban areas. There is growing concern about their growing populations. Joro spiders are venomous, and families are concerned about the safety of these spiders around their pets and children. In addition, invasive species often pose threats to local ecosystems, and there is growing concern for how the Joro invasion is going to affect native flora and fauna. Lastly, it appears that the Joro population is slowly starting to spread northward, and many are beginning to worry that the Joro troops are planning to dominate the entire east coast, and maybe even… the world.

 

To address these concerns, I would like to begin with the assertion that Joro spiders look a lot scarier than they really are. While these spiders are venomous, their venom is only potent enough to kill small insects. If a human is bit by a Joro spider, which is unlikely, it will hurt less than a bee sting and will not require medical attention. Despite their threatening stature, Joro spiders are, for lack of a better word, babies. They are a very docile and non-aggressive species of spider. A study conducted in 2023 by blah, was evaluating how different species of spiders reacted to a environmental stressor. When blown with a light puff of air, most spiders in the study responded by freezing for less than a minute. The Joro spider, however, reacted to the stressor by freezing for over an hour. It is safe to say that these spiders are not going to attack humans or animals they see as a threat.

 

Concerns about how Joro Spiders may impact local ecosystems are much more valid. As of right now, scientists are unsure of exactly how these new Joro spiders will impact the environment. It is clear that they have cemented their spot as top predators of the arachnid world, and it is likely that they will out-compete native spider populations for food. This could threaten local spider and insect populations, which could lead to eventual destabilization of ecosystems, but the extent to which ecosystems will be affected is still up for debate.

 

The good news is that many scientists are optimistic about the effects that Joro Spiders will have on the environment, some going as far as to say that they may be beneficial. In general, spiders are key pillars of healthy ecosystems, as they control insect populations and act as a key source of protein for birds. Additionally, there is no evidence that Joro Spiders pose any threat to the environment apart from potentially destabilizing insect and spider populations. Take the invasive Spotted Lanternfly, which was introduced to the US from China in 2014 These insects have had disastrous consequences on agriculture due to their intensive feeding of various trees and crops. Americans are advised to kill these lanternflies on sight due to their environmental impact. Luckily for it, the Joro Spider has yet to exhibit any behaviors that could pose a similar threat and could warrant similar measures. In fact, Scientists are optimistic that Joro Spiders could help the environment by preying on another invasive species, the Brown Mamorated Stink Bug. This bug was introduced to the US from East Asia in 1998 and caused significant agricultural damage through their feeding habits. There are very few natural predators of this stink bug, which has allowed their populations to boom. The Joro Spider, however, will happily feast on this stink bug, which could potentially keep their population in check.

 

So, where are Joro Spiders headed now? As of right now, Joro Spiders are confined to the southeast, concentrated in Northern Georgia, Tennessee, and the Carolinas. There have been a few sightings of these spiders in Oklahoma, Maryland, and West Virginia, likely from being transported by car; however there is not evidence of any permanent or expanding Joro populations this far north. Joro Spiders prefer the warm climate of the southeast, and they are unlikely to move farther north. However, with climate change continuing to progress, it is possible Joro Spiders may increase their reign as a larger portion of America becomes habitable for them. At this point, it is difficult to predict.

 

So, to answer the question, “Are Joro Spiders Going to Kill Us All?” is a definite no. While their large webs and bright colors might seem intimidating, Joro spiders are quite harmless to humans and pets. Although their presence does raise ecological concerns, particularly for native spider populations, scientists remain cautiously optimistic. For now, residents of the Southeast can coexist peacefully with these giant newcomers and perhaps even appreciate the role they play in keeping insect populations in check.

 

 

 

Works Cited

 

Bugwood. (2024, November 5). Home. Joro Watch. https://jorowatch.org/

 

Joro Spider is a unique exception to a major threat. Big Think. (2022, May 20). https://bigthink.com/life/joro-spider-invasive/

 

Meadows, K. / S. (2021, September 6). Joro spider update: Controlling this invasive species. Joro Spider Update: controlling this invasive species.

https://gardeningsoul.blogspot.com/2021/09/joro-spider-update-controlling-this.html

 

Pappas, S. (2024, June 11). No need to panic about the joro spiders. Scientific American. https://www.scientificamerican.com/article/millions-of-joro-spiders-are-moving-up-the-east-coast-heres-what-to-expect/

 

Spotted lanternfly. Spotted Lanternfly | National Invasive Species Information Center. (n.d.). https://www.invasivespeciesinfo.gov/terrestrial/invertebrates/spotted-lanternfly

 

Walling, M. (2024, June 7). Everything you need to know about the invasive joro spider. PBS. https://www.pbs.org/newshour/science/everything-you-need-to-know-about-the-invasive-joro-spider

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What makes a figure interpretable?

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  Timothy Durham was convicted of rape when a test showed his DNA genotype matched the DNA recovered from the crime scene. Eye witnesses testified that Durham was in a different state at the time of the incident, but he wasn’t exonerated from his 3000 year sentence until follow up DNA analysis showed that the preliminary forensic analysis used in the trial was misinterpreted (Thomas et al.). DNA testing serves an invaluable part in our criminal justice system, but it comes with complications and bias that can lead to wrongful convictions and misinformed juries.  

Background:

Forensic genetics aims to identify the origin of a biological sample. It can be traced back to Karl Landsteiner who discovered human ABO blood groups. With blood groups, suspects could be eliminated based on their blood type. For example, if a suspect had type A blood and there was type B blood left at the scene by the perpetrator, the investigators could rule out the suspect. Unfortunately, the reverse didn’t work. If the suspect and perpetrator both had the same blood type, it can’t be concluded that the suspect was guilty. Blood identifiers evolved into 8 distinct categories which improved the ability to eliminate suspects, but could only conclude that (if the system matched) it might be the perpetrator or this person might be related to the perpetrator (Jobling and Gill). The field evolved in the 1980s with the discovery of Minisatellites, lines of repetitive DNA that don’t encode proteins. Minisatellite patterns in DNA create what we know today as the DNA fingerprint, and it has a much higher accuracy rate than previous methods (Augustyn et al.). Around the same time, a breakthrough for victims of sexual assault was discovered. In the case of assault, bodily fluids of both the victim and the assaulter can get mixed. A process called differential lysis was created which could selectively increase the concentration of sperm in a fluid sample thereby allowing for accurate DNA testing (Jobling and Gill). Forensics evolved to use single-locus probe testing after several years because of its ease of interpretation. It looked at specific minisatellites that had high variability between subjects. This was the first DNA-based method to be used in a criminal investigation. Two murder homicides from several years apart were connected using DNA evidence. The evidence was then used to exonerate an innocent man, and the guilty party was found when he tried to evade mandatory DNA testing for all men in the small town. His guilt was then reinforced when the DNA profiles matched, and he gave a confession (Jobling and Gill). Finding DNA at a crime scene doesn’t guarantee that you’ll find a murderer. There are issues with non-pure samples and limited samples that make DNA work difficult, and accreditation of facilities and new techniques and take time (Jobling and Gill).  

Subjectivity of DNA Interpretation:

In a 2009 publication, the National Academy of Science discusses the possibility for subjective influence in lab based forensics. The interpretation bias happens in complex cases where, for example, there could be a mixture of DNA. A study published in 2011 looked specifically at this issue. A gang rape happened in Georgia, and the mixture in DNA from the case was used to prosecute one suspect after another suspect took a plea bargain to testify against him. With DNA mixtures, there are three possible conclusions: suspect excluded, suspect cannot be excluded, and inconclusive. If the suspect is excluded, it means that there’s little to no possibility that his DNA is part of the sample. If the suspect cannot be excluded, it means that there’s a possibility that his DNA is part of the sample. In the trial, the DNA examiners who knew the context of the case concluded that the suspect being prosecuted could not be excluded. The 2011 study gave the DNA evidence from this case and the DNA profiles of the suspects to 17 forensic examiners. These examiners had no context of the case, and they all worked independently. Of the 17, only 1 came to the same conclusion (suspect cannot be excluded) as the examiners who knew the context of the case. Twelve of the 17 concluded that the suspect who was prosecuted and convicted had no relation to the DNA found in the sample. Not only does this show that subjectivity occurs due to the context of the case, but the 17 examiners came up with different findings based on their past experiences meaning that not all DNA analysis is objective. Some organizations like the Scientific Working Group on DNA Analysis Methods say that quantitative statistical evidence should be presented with every categorical conclusion, but the US doesn’t require this (Dror and Hampikian).

False Positives:

There are two categories that cause wrongful identification in a DNA report: coincidental matches and false positives. Coincidental matches are DNA matches between two unrelated people. The probability of these matches is about 1 to 500,000 for white individuals and about 1 to 350,000 for black individuals. This small probability of coincidental matches makes people feel confident in DNA evidence. False positives, on the other hand, are matches between DNA and test DNA that result from issues in the forensics lab. There have been multiple cases of forensics labs accidentally switching victim and suspected rapist DNA which lead to convictions that were later overturned when the lab realized the error. There are also cases of misreading or misunderstanding a sample. In a case from 1993, a man was convicted of rape because someone interpreted a mixed sample of victim and perpetrator DNA as an individual sample. The conviction was again overturned. To prevent false convictions, retesting DNA is allowed, but it’s not an efficient solution. Many people are pushing for statistical information on the probability of false positives, so that the jurors can make accurate judgements based on DNA evidence (Thomas et al.).  

Conclusion:

DNA analysis is a useful tool for the criminal justice system, but subjectivity can be an issue in forensic testing. To combat wrongful convictions, there are organizations like The Innocence Project who use DNA testing to free the innocent, but reformed forensic testing standards should be put in place to prevent subjectivity and to ensure juries are correctly informed during trials. https://www.innocenceproject.org/    

Citation:

Augustyn , Adam, et al. “DNA Finerprinting.” Encyclopedia Britannica , 26 Apr. 2018, www.britannica.com/science/DNA-fingerprinting#ref153186. Dror, Itiel E., and Greg Hampikian. “Subjectivity and Bias in Forensic DNA Mixture Interpretation.” Science & Justice, vol. 51, no. 4, 2011, pp. 204–208., doi:10.1016/j.scijus.2011.08.004. Jobling, Mark A., and Peter Gill. “Encoded Evidence: DNA in Forensic Analysis.” Nature Reviews: Genetics, vol. 5, no. 10, Oct. 2004, pp. 739–751., doi:10.1038/nrg1455. Thompson, William C, et al. “How the Probability of a False Positive Affects the Value of DNA Evidence.” Journal of Forensic Sciences, vol. 48, no. 1, Jan. 2003, pp. 1–8., doi:10.1520/jfs2001171.