Handbook of Nature-Study · Lesson LXXXV · Topic 12: The aquarium and pond insects
85. Dragon-flies and damsel-flies
Goal: Your child can tell a dragon-fly from a damsel-fly, describe how both hunt, and know that their young grow up underwater.
You'll need
- A sunny pond or slow stream at midday
- Binoculars (close-focusing ones are best, optional)
- A dip-net or kitchen strainer and a white tray or dish
- A sheet of writing paper
- A nature notebook and a pencil (colored pencils if you have them)
What's in the book
Comstock's story of dragon-flies and damsel-flies: the silly old names and beliefs about them, their swift hunting flight, their huge eyes, and their underwater nymphs with a folding lower lip for catching prey. Then Lesson LXXXV with its leading thought, a method for nymphs in spring and adults in late summer, questions on the nymphs and the adults, and an outline for field notes.
The lesson, step by step
When and where
Adults: sunny days from late spring to early fall, best at midday over ponds and slow streams. Nymphs: Comstock says "April and May are the best months for securing them," in the bottoms of reedy ponds.
Safety first
Water safety: an adult stays within arm's reach of young children at the water's edge. Keep back from steep or slippery banks, and wash hands after handling pond water, mud or water creatures.
Comstock asks children to catch a dragon-fly and put it under a tumbler. Their wings tear easily, so we watch them perched instead. A large nymph can give a small nip; tip it into the tray rather than holding it.
Keep the big idea in mind
Comstock's "leading thought" is the one idea the lesson is meant to lead to. Read it to yourself now, and save it to share at the end, after your child has looked and answered:
The dragon-flies are among the swiftest of all winged creatures and their rapid, darting flight enables them to hawk their prey, which consists of other flying insects. Their first stages are passed in the bottoms of ponds where they feed voraciously on aquatic creatures.
Watch them hunt
Do you see dragon-flies darting over the pond? Describe their flight. They are hunting flies and mosquitoes and other insects on the wing; note how they do it.
In looking over a pond where there are many dragon-flies darting about, do the larger species fly higher than the smaller ones?
Dragon or damsel?
Find some that are resting on reeds or sticks.
Note the way the dragon-flies hold their wings when they are resting. Do they rest with their wings folded together over the abdomen or are they extended out at an angle to the abdomen?
The damsel-flies are those which hold their wings folded above the back when resting. Are these as large and strong-bodied as the dragon-flies? Are their bodies more brilliantly colored?
Strong, light wings
Try Comstock's paper experiment:
Take a piece of writing paper and see how easily it bends; fold it two or three times like a fan and note how much stiffer it is. Is it this principle which strengthens the dragon-fly's wings?
The young in the pond
In spring, sweep the net through the mud and weeds and tip it into the tray of water.
Where did you find these insects? Were they at the bottom of the pond or along the edges among the water weeds?
Look on the rushes and reeds along the pond margin, and see if you can find the empty nymph skins from which the adults emerged.
Put the nymphs back in the pond when you're done.
Nature notebook
Draw a dragon-fly and a damsel-fly at rest, side by side, so the different wing positions show. Then read the leading thought aloud and add the date and the pond's name.
Tip
Comstock says dragon-flies are entirely harmless to people, despite old names like "devil's darning needles." They eat a great many mosquitoes, both as nymphs and as adults.