The Strange Case of the Caddisfly

Posted on July 26, 2013 by BIObus Crew

When we were finishing retrieving an aquatic bottle trap from Blue Hill today we happened to find some tubes of carefully interwoven pine needles. While these types of things would normally go unnoticed by being inconspicuously small and blending in with the neighboring debris that has been swept to shore, what we were actually looking at was the discarded casing of a caddisfly larva (from the order Trichoptera).

Caddisfly larva typically spin webs from glands in their mouth and, in case building species, will collect surrounding debris and other bits of nature to make their home. They keep both ends of their case open so that they can have a continuous flow of water (going from posterior end to anterior end) in order to breathe. To make sure that they don’t fall out they will hold their home in place by a pair of hooked prolegs at the end of their abdomen. Once they have matured they will bite through the case and abandon their homes to join the world of flight. Caddisflies are adults for merely a week or two of their year-long lives, and often they do not feed when they’re mature. The ability of caddisflies to make their homes from surrounding debris has been harnessed by bug-savvy jewelers to create one-of-a-kind pieces that you can wear.

A jewel encrusted caddisfly larva from www.cabinetmagazine.org

Other caddisfly larva will create silken nets to filter and funnel water-borne food to their mouth, and some do not make silk cocoon-like structures at all and are free-living in the water. Learn more about other water-linked species in Forest’s blog on the fascinating lives of dragonflies!

Greetings from Terra Nova National Park!

Jill

P.S. The Barcode of Life Initiative has a Trichoptera campaign! Check it out at www.trichopterabol.org

Do it yourself bug collecting

Posted on July 20, 2013July 26, 2013 by BIObus Crew

As we tour between national parks a common question that we are asked is how do you collect insects? Not only is it easy to make lots of our traps, it is a great summer activity for the young and young-at-heart insect enthusiasts. Some of our traps like malaise traps, intercept traps, and bucket traps have more elaborate set ups, but most of traps are a fairly simple design made with household items or things readily accessible from your local hardware store.

The simplest traps are what we call pan traps, they are simply wide yellow bowls partially filled with soapy water (the yellow is to attract pollinators and the soap is to decrease the surface tension of the water). The trap is up for as long as you’d like to collect for (we usually collect over a week). From my experience these work best in areas that are open and sunny- although if you place them in a forest you’ll still get a lot of cool things!

Another type of trap you can set up is called a pitfall trap. They are simply a deep dish (Dixie cups work great) that is placed inside of a pit that you make in the ground. Insects that crawl along the surface of the ground will then fall into the cup so you want to make sure that the ground is flush with the edge of the cup. Fill the cups with water or soapy water, or alternatively, you can do a catch and release style and not fill up the pitfalls at all. The only downside to not filling the traps with anything is that flying insects may get away and you may create a battlefield in the cup with all the different types of insects.

If you have the opportunity to do some aquatic collecting, one of my favourite traps is the bottle trap. First off you’ll need two 2-litre pop bottles with their bottoms cut off. Then take the lid off of one and place it inside of the other bottle top, staple the two together and attach a string to the cut end of the bottles and Voila! You have your own handy dandy bottle trap. You’ll only need a glow stick to make the trap complete. When the sun is starting to set crack the glow stick and take the cap off the bottle, put the glow stick in-between the two bottles and put the lid back on. Place the bottle trap inside of the water (a marsh works best and make sure the trap fills with water) and tie the string to a nearby stick or pole and leave it for the night. Reel in the trap in the morning and check out what you caught! For easy viewing you can put your catch inside of a large glass container or into a wide dish by taking the cap off while holding the trap over the container. Once you’re done watching the aquatic things you can always return them back to the water.

For fun you can set up lots of traps in different areas and see which areas are the most diverse and which give you the most bugs!

Happy collecting!

– Jill

Recent