Sunday, October 10, 2021

Invasive Spiders Don’t Have to Stay

 

Last year I wrote about the non native and invasive Jorō spider that arrived in Georgia in 2014-2015. I had visited an area in Cumming that had quite a few of them, not terribly far from me. I saw none in my neighborhood last year. This year I have had over 30 in my yard, in my neighbors’ yards, and in the area just outside my neighborhood where I walk. I have killed every one that I could reach. I expect to have hundreds next year.

Jorō spider (Photo: Sarah Sanke); messy golden web

Discussion about this spider has exploded in North Georgia as more and more people have seen them and experienced how prolific they can be. People in areas like Cumming, Gainesville, Athens, Alpharetta/Johns Creek, Dunwoody, and Buford are reporting hundreds of them in residential yards and parks. UGA has put out a couple of articles that have been picked up by national news (USA Today, for one) indicating that they are ‘here to stay’ and nothing can be done. I have found their response to this infestation to be not only a disappointment but also a hindrance to any progress removing them. One particular article was especially galling as a UGA employee said we should be happy to have “zillions” of them for pest control. 

People point to these articles as “proof” that they should not bother to deal with them - "UGA said we shouldn't bother". Have we given up on kudzu? Do we not try to control pests like tiger mosquitoes and the woolly adelgid? We continue to fight these invasive species and we should do so with this spider. We have seen the future and it cloaks our yards and natural areas in large, exceptionally sticky webs, killing pollinators and spoiling human enjoyment of our own yards. People in Gainesville and Cumming can give you an idea of what living with 'zillions' of them means. 

On top of insect declines thanks to residential mosquito spraying, now our pollinators have to deal with 2-8 foot webs (some spiders join together to make large communal webs). Our small birds are at risk of being caught in these very sticky webs, dying of exhaustion. I have found webs with numerous dead bees in them.

Good information has finally come out that they are most visible in late summer (August-September) with females creating egg sacs in October. Now is a critical time to kill them to reduce future populations. The Center for Invasive Species has created a visual aid to compare the Jorō to other native spiders and that is helpful; we don’t want people to kill the wrong spiders.  Unfortunately even that source (Center for Invasive Species) is not actively recommending that people kill them.

What will it take for our public university to at least get off their “oh well, what can be done” stance and encourage people to reduce the population of these spiders? They should be giving guidance to cities and counties that manage public parks on when to look for these and how they might control/remove them. Otherwise we will see pest companies take up the charge in response to homeowner requests, potentially fogging areas with more chemicals than necessary, further harming native insects in the process. Finally, a somewhat balanced article came out two days ago, but for many the message to ignore them was already received.

So, choose for yourself if you want to let these spiders increase their populations but please consider that spiders in your yard this year also mean more for you and your neighbors next year. Notice the difference in the two iNaturalist maps; the 2021 map shows denser populations as well as dramatically increased range. The 2020 map did not have reports in TN, NC or SC and metro Atlanta is now quite dense with reports.

2020 map is a detail of reports which were only in GA

2021 map is further out to show increased range


My method for spotting them includes looking for floating leaves that were caught in the web. Then I look more closely to determine if it is a Jorō or a native spider. They are often up high but I’ve found them just 3-4 feet off the ground in vegetation. They like power poles. Once I identify it as a Jorō, I use a broom/rake or long stick to reach up above them and try to quickly wrap the web and the spider up together and get them to the ground where I squish the spider. I know that some people are using the long-reaching bug sprays (hornet/wasp) to hit the ones that can’t be reached manually. Regardless of how you kill the spider, do try to get the web down so that bugs/birds don’t get caught. I am also seeing new spiders move into choice locations where I removed one before so double check spots.

We don't have to tolerate these invasive spiders. Take action now to reduce next year's population.


Red spot is noticeable
Very pregnant female



9 comments:

  1. I agree Ellen. We really need to get ahead of this if it's still possible. Thanks for speaking out.

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  2. Thank you Ellen. A great article, and the pics are very helpful. Im sharing this with my HOA

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  3. The article being shared from UGA was not only dissapointing but irresponsible, in my opinion.

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  4. Thank you, Ellen, for putting forth our concerns so succinctly in your blog. Definitely will be shared far and wide.

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  5. Excellent article and Thank you! I am in N Hall county on Lake Lanier. The joros are favoring power lines and building continuous nests between the upper lines. The glow brightly in the sun, one after the other and on and on. Its horrible. I kill all in my yard using Ellens technique,

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  6. Adding my thanks to the list. I've had at least two in my Decatur garden, and will be on the lookout for more next spring.

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  7. For what it's worth, I saw about a dozen when I was in Auburn, Alabama last month.

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  8. Thanks Ellen for speaking out about this. I've been on the lookout but haven't seen any yet in my intown Atlanta yard or local nature parks, but it's only a matter of time. My yard is too small for them to set up shop so I'll get rid of them if I see them next year. My only worry is people killing any large spiders they see like the zipper spider which is large and has a similar egg sac or the marbled orb weaver...so more spider education is needed about the joro's distinctive red belly!

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  9. Thank you for your article. I am not a proponent of killing any type of wildlife but this is an invasive species and I'm afraid of what impact they may have if we do not act. I view these much the same as the Hemlock Woolly Adelgid or the Lionfish. I was not overly concerned until this past week when I was shocked to see hundreds of webs covering every available spot on the powerlines for 7 miles leading from my house to my daughters school. Although it does look very seasonal and spooky in the early morning fog, I can't help but wonder what will happen next year.

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