Spider Ground Control to Arachnid One

Hi everyone,

I just returned from a week of aquatic sampling at Point Pelee National Park and have much to share. The peninsula that is Point Pelee is the most southern part of Canada and it is revered as one of the best spots in North America to observe the spring migration of songbirds. The park itself exists largely due to the efforts of W.E. Saunders who arrived at Point Pelee in 1882 with the intention of duck hunting. However, when he saw the abundance of bird species in the area he quickly lost his interest in hunting. With the help of his friends, Saunders would go on to establish the Great Lakes Ornithological Club (GLOC). One of its founding members was Percy Taverner who became Canada’s first Dominion Ornithologist. Taverner forwarded a proposal to the Federal Commission of Conservation that Point Pelee be granted national park status. Over the next few years, Saunders, Taverner, and the rest of the GLOC reached out to avid ornithologists and conservationists alike. In 1918, the amassed local support along with the ornithological evidence provided by the GLOC convinced the Federal Commission and Point Pelee was declared a National Park.

he BIObus has arrived at Point Pelee National Park
The BIObus has arrived at Point Pelee National Park

When we were driving into Point Pelee I was excited to see numerous signs advertising spider control and removal. With this many signs for spider control, I was thinking that there must be tons and tons of spiders in the area – great news for a novice arachnologist! Unfortunately, my hopes were dashed when I discovered that there wasn’t a problem with spiders so much as there was with harvestmen. They are two completely different organisms and I figured that this would be a great time to explain the difference between spiders and harvestmen. The confusion stems from the fact that the common name daddy-longlegs is applied to both harvestmen and spiders of the family Pholcidae. Although both are in the same class of Arachnida, spiders are members of the order Araneae while harvestmen belong to the order Opiliones. That may be a little too technical, so here are some easy ways to tell the difference between the two. First off, the body of a harvestman appears to be one continuous segment whereas spiders have a clearly defined abdomen and cephalothorax. Secondly, harvestmen have two eyes while spiders can have anywhere from zero to eight eyes. Thirdly, harvestmen lack silk glands and unlike spiders, cannot build webs. The last easy way to see the difference is that harvestmen lack fangs and therefore cannot bite. As we all know, spiders have fangs and can bite their prey or anyone that disturbs them too much.

A harvestman has eight legs, just like a spider! (Order: Opiliones)
A harvestman has eight legs, just like a spider! (Order: Opiliones https://en.wikipedia.org/wiki/Opiliones )

 

A genuine daddy long-legs spider (order: Araneae, family: Pholcidae https://en.wikipedia.org/wiki/Pholcidae).
A genuine daddy long-legs spider (order: Araneae, family: Pholcidae https://en.wikipedia.org/wiki/Pholcidae).

 

As I mentioned at the start of this blog, the BIObus team was at Point Pelee to do some aquatic sampling. We were collecting aquatic invertebrates and one of the methods we used is called kick and sweep collecting. To use this method, one team member wades out into the water with a D-shaped net. This is easier said than done as the wetlands we sample are usually full of squishy organic matter or stiff woody debris that can easily trip us up. Once the collector has waded out far enough, they walk backwards with the net in front of their shins, trying to kick up the tiny aquatic invertebrates as they go. I’ve gone a step further and actively dance when I am doing this method of collecting. Field work can be tough and sometimes you just need to enjoy the little things.

Measuring how far Connor goes into the water. Don't fall Connor!
Measuring how far Connor goes into the water. Don’t fall Connor!

Thanks for reading,

– Josh

Leave a Reply

Your email address will not be published. Required fields are marked *