A Call for Spider Hunters!

Are you a fan of Citizen Science, where volunteers assist real scientists in any of several ways? You'll want to answer a call from Dr Catherine Scott, a spider scientist. At the end of May 2022 she shared on Twitter a call for nature fans to report their spider sightings. She wrote:

Have you started to see candy-striped spiders out & about? Please help us to learn more about these introduced predators in North America by joining the Spider Hunters project! 

Dr Scott is an arachnologist and spider advocate, a natural historian and behavioral ecologist. She used to be afraid of spiders, but now she spends much of her time outdoors searching for spiders and learning new things about their lives. Dr Scott is also active in social media conversations about the natural world. You can find her posts on Twitter at @Cataranea. On July 6 she wrote:

Candy-striped spider season is now well upon us! Please keep an eye out for these spiders and submit your observations to @inaturalist, where they will automatically be added to the #SpiderHunters project. Thanks! 

If you're not on iNaturalist, please feel free to submit sightings to me directly: email photos to mail@spiderhunters.ca!

These candy-striped spiders are not dangerous to people! They hitchhiked a ride to North America on human ships. In North America, candy-striped spiders are an unexpected predator for insects that pollinate flowers.

Dr Scott goes on to add:

Do I know anyone in Saskatchewan? Do you? I am particularly keen to find out whether or not candy-striped spiders are there (yet)! There were records, but they turned out to be mis-IDs. This is the only province where they may not be!

The Japanese Beetle in Vancouver

By Raymond K. Nakamura

The first I heard of the Japanese beetle (Popillia japonica) was on signs in my neighbourhood calling for its eradication. In its native Japan, the green and copper member species of scarab beetle is called “mame-ko-gane” in Japanese, which means “bean yellow gold” or “mini gold money.” Natural predators keep it under control, although recent increases have been associated with the growth of well-manicured golf courses. 

People first noticed it in North America in 1916 on the east coast of the United States, presumably introduced on imported plants, some time before 1912, when screening became a thing. Lacking natural controls in North America, the Japanese beetle has become an invasive pest. The whitish, C-shaped larvae eat the roots of grass, while the adults, which feed on the leaves of about 300 species of plants important for food and gardening.

In 2017, routine insect surveys first detected the Japanese beetle at David Lam Park in Vancouver. Since 2018, the Canadian Food Inspection Agency (CFIA), the City of Vancouver and other cities, along with organizations such as and the Invasive Species Council of BC (ISCBC) have been working to get rid of the beetles before they become a big problem. 

To control the spread of the beetles, the movement of plants and soil is restricted in parts of Vancouver and now Burnaby. Landscapers in the area have to use special transfer stations. Traps have been set up to monitor and remove adult beetles. The fins on the traps have a floral scent and a pheromone to attract the adults. They are weak fliers and when they smack into the fins, they tumble down into the containers below. Technicians check them every few weeks, recording and disposing of any finds. In addition, areas where larvae are suspected, the City of Vancouver is applying the larvicide Acelepryn, which is is supposed to target the larvae, while being safe for people, pets and other preferred creatures.

I may have overreacted in my cartoon because the signage triggered memories of the wrongful incarceration by the Canadian government during World War II of my parents and grandparents, along with more than 20,000 people of Japanese descent, most of whom were naturalized citizens or born in Canada. The province of British Columbia recently acknowledged its role in that time. It also brought to mind the rise in Anti-Asian violence during the pandemic. And on the other side of the Pacific, I had relatives who were affected by the radiation from the atomic bomb dropped on Hiroshima.

I’m not saying that the treatment of the invasive species has anything to do with that, but after I first posted the comic on social media, Jennie McCaffrey, Director of Engagement at the Invasive Species Council of BC reached out to me,

“I wanted to let you know that the Japanese beetle name is troublesome for many and we (Invasive Species Council of BC) get questions about it. We are limited because it is the official name decided by the international entomological society. However, they are in the midst of making change! Just this year the 'Gypsy Moth' was changed to 'Spongy Moth' so we are hopeful that happens soon for the Japanese beetle common name.”

 

Jellyfish Aren’t Just for Saltwater

By Adrienne Montgomerie

“Mom, we saw jellyfish!”

“No way. We’re in a lake. Jellyfish are saltwater creatures.”

“No, really, honey," his dad said. "There were jellyfish.”

“Well that’s cool,” I said with total skepticism.

The next day, I said I wanted to see the jellyfish. Totally bracing for the “we’re just kidding” punchline, off we went.

Canoeing into a little bay of a medium sized lake in eastern Ontario, my son dipped a pail in the water, and pulled up several jellyfish about the size of a quarter. White, but mostly transparent. They looked almost like large contact lenses. Delicate, undulating in the green bucket.

The bay was full of them. A bloom of jellyfish. In fresh water.

They didn’t sting. Or if they did, they were so small that it was hard to tell. I didn't want to touch them because they are so delicate. I had to learn more about this.

It turns out that these jellyfish (C. sowerbii) are an invasive species, and they are quite widespread across North America. You can report sightings of them on the Freshwater Jellyfish website.

How Long Have Jellyfish Been in North America? 

This year there are thousands of news reports about the freshwater jellyfish, but there have been confirmed sightings in Canada and the USA as far back as 1934. There are even reports from the 1800s in London, England. Sightings are reported throughout Canada and the USA, but that 1934 sighting was in Horseshoe Lake near Ste. Agathe-des-Monts, Quebec.

How Can I Get a Closer Look?

If you want a closer look at these jellyfish, you can scoop some up in a clean bucket for a few minutes. Be sure to gently put them back where you found them. Check the sightings at FreshwaterJellyfish.org to find a likely lake.

They are big enough to see with just your eyes, but a magnifying glass will help you get a closer look.

The adult stage only lasts several days, so you may not find them when you go to look. It takes about a month for a jellyfish to grow. I saw them bloom on a very warm weekend one Thanksgiving but there are many reported sightings in mid-summer.

Where Did Freshwater Jellyfish Come From?

They probably came in the water inside a ship from South America, or on imported water plants from China.

They are found in crystal clear water, in slimy ponds, and in every kind of water in between.

How Can We Help Prevent Them from Spreading?

Clean boats and water toys in hot soapy water, just as you would to stop the spread of zebra mussels and gobies.

Don’t take plants from an infested place and put them in a new place.

Can you Keep at Jellyfish at Home?

Delicate and eerie, jellyfish have a mesmerizing appeal. Like any wild animal, they are healthiest when left in the wild. Like any invasive species, it’s best not to transport them to new areas, where they can infest more lakes.

Aquariums that keep jellyfish find it very difficult. None have been able to keep freshwater jellyfish on display. They usually only live a few days in captivity.

It takes special equipment to keep the pH correct and the water circulating continuously, and they need a constant supply of fresh plankton. Raising jellyfish takes a lot of attention. An aquarium is hazardous itself, as the delicate jellyfish can get sucked into filtration systems and pumps, and air bubbles can get trapped inside the jellyfish, holding them at the surface.

Are Jellyfish Harmful?

Freshwater jellyfish do sting, but their stinger is so small that it can’t seem to penetrate human skin. Some people do feel an irritation but it seems to be easily washed off.

It’s not yet known how these creatures will affect the ecosystem. They do eat plankton, which other species rely on, creating competition for the food. They are also eaten by gulls, crayfish, and turtles, providing new food that may help those species thrive (which in turn can affect other species that compete and rely on those animals). Few organisms have a zero sum impact on the environment they live in. We just haven’t seen the full effect yet.