It's been a while since I've posted once again, sorry!
I think I'm going to take a break from the logging chats and talk about something cool that has been taking place the last couple weeks. As I was out along the St Croix River last weekend I happened to look up in several locations to see hundreds and hundreds of dragonflies flying around! "Yeah, so what Katie," you might say, "what's so great about dragonflies?" Well, I'm glad you asked!
I love dragonflies for a multitude of reasons. The number one reason however is the fact that they eat many hundreds of biting insects a day!
Another reason these critters are so cool is their phenominal life cycle! Dragonflies start their lives out much like most other aquatic insects, as an egg. When you see a dragonfly flying above the water and occasionally tapping her abdomen into the water, she's actually laying her eggs. Some species will actually insert their eggs into the stem of an aquatic plant! (Some people say they've been bitten by a dragonfly but odds are it was just the female mistaking them for an aquatic plant.)
Anyway! They start out as a mass of eggs, that look something like this:
These eggs can live in this stage for a range of times depending on when they were layed and what species they are. Some will last only a few days as eggs where others will make it through the winter in this stage.
Once they hatch out they become a water insect that's called a dragonfly nymph or larvae. Again, with there being so many different species of dragonflies, there are a lot of different sizes and shapes of these water bugs. Here's a great picture of a dragonfly nymph:
As you can see these guys are pretty fierce looking, almost like a dinosaur. It's pretty fitting too since they are like a living dinosaur! We'll talk about that later though!
So when they're in their nymph stage dragonflies are pretty spectacular. They are great predators and will eat just about anything they can catch. In fact, in an ecosystem where dragonflies are present, when they're in the nymph stage they're pretty much the top of the food chain! They'll eat other aquatic bugs, tadpoles, and even small fish if they can catch them. WOW!!
Now something else that's pretty cool about these guys is that some species can live in this nymph stage for up to eight years! EIGHT YEARS!! They're pretty easy to catch when they're nymphs as well. We like to take an aquarium net down to the river and tap it along the bottom of the river along the shore. Without fail we always come up with one of these guys. Just like humans, different speices of dragonflies like to live in different places. Some prefer fast flowing water, some prefer slow moving water, and some just prefer to live in a lake or pond setting where the water isn't really moving much at all.
If you do find one of these guys in the water take a good look at them. If you're able to clearly see where his wings are going to be then you've found one that's almost ready to emerge!
In the spring when both the air temperature and the water temperature start to warm the dragonflies start to emerge in large numbers.
What will happen is when the time is right the dragonfly nymph will crawl out of the water and with his legs hill hold onto something. (Their legs are sticky kind of like a grasshopper's) And they'll hold on to a log, a rock, a stick, a piece of grass, pretty much anything! They'll hang out there and start gulping in water. Gulp gulp gulp! Until their back SPLITS right open, and then they'll pull themselves right out of the bug!! A good way to think about it is like a caterpillar and it's cacoon.
Crazy right!?!?!?
SO! Remember how I said when they live in the water they're near the top of the food chain? Well things change quickly once the emerge from the water! If you've ever been swimming too long you know that your skin gets kinda pruny and wrinkley right? Well imagine these guys that have lived in the water for a few years! Their bodies are soft and they need to hang out and let their bodies, legs, and wings dry out before they can fly away to safety. So in this time, they're really vulnerable. They have to hope that nothing comes along that would want to eat them like a fish, a bird, a spider, and most definately, frogs!
So if they survive the drying out process, they're able to fly away and finish maturing away from the water source before they return!
It is TOO nice of a day to stay inside and talk about dragonflies, so I'm going to go outside and enjoy this beautiful weather and maybe say thank you to some dragonflies for eating those pesky mosquitoes!
I hope you are all doing well and remember to TAKE IT OUTSIDE TODAY!!
Photos are all NPS photos.
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