Once a year I meet with him for a bite to eat and a chat. More often is not necessary as far as I’m concerned, because to be honest he’s kind of boring. If I had met him in adulthood, we probably never would have become friends, but we have known each other since childhood. Then he was anything but boring.
We are sitting on a terrace by the water, where a fairly large, yet inconspicuous creature sits just next to my left shoe. It disappears against the brownish, colorless background. The only thing that stands out about it are the relatively enormous wings that are folded like a roof over the much smaller abdomen. The order to which this insect belongs is not called Great-winged, or Megaloptera, for nothing. More specifically, it is an alder fly, Sialis lutariawho sits motionless at my foot. The large wings are brown. Very distinct, darker veins run through it. But no matter how huge those wings are, the alder fly cannot fly well. He’s more of a clumsy flutter, landing as quickly as possible.
Couples
Mating is also not very easy when you are so generously winged. Those things just get in the way. A male alder fly that wants to bring his genitalia into contact with that of a female has to curl up his hind body between the spread wings and try to leave his seed inside her in that complicated position. If his acrobatics are successful, she can start laying eggs. She does this in tight rows and columns around a twig or on a leaf that hangs above water. The pattern she weaves in this way is very characteristic.
When the larvae hatch from their eggs, they drop into the water, where they will develop. Those larvae are reminiscent of centipedes, just like my childhood friend as a child. He did and could do everything from long division to soccer and swimming. Alder fly larvae can also do the latter as the best.
In the water, these animals fiercely hunt other invertebrates
They are elongated creatures that seem to have a lot of legs. Of course that is not possible, because insects never have more than six. In addition to three pairs of legs, alder fly larvae have eight pairs of spindly projections on the sides of the body. Those are gills. They can even breathe in stagnant and therefore little oxygen-rich water, which explains the other Dutch name, mud fly.
In that water, these animals fiercely hunt other invertebrates. With their powerful jaws, they prey on prey such as mosquito larvae and caddis flies. Once fully grown, they crawl out of the water to pupate in the bottom, after which the adults do little more than look for a drop of nectar and a mate.
The childhood friend no longer swims. He sits in an office being colorless. Somewhat relieved that this year’s meeting is over, I wave him goodbye. I look at the alder fly that hasn’t moved the whole time. Yet insects are much less boring.