I got a plant with only a few of these pests on it. I picked them off by hand and thought nothing more of it. I didn’t realize that they had tiny babies that I overlooked and that although they move extremely slowly, they reproduce at a high rate.
Coins for scale (pun intended); depending on where you are, Canadian 25¢ (same size as American), British £, 2€ and 50 Kč (Czech crowns) from my trips this year.
The leaf is a Swiss Cheese Plant (Monstera deliciosa) which has thick, leathery leaves. I hadn’t noticed that it had got some of these insects on it, must have crawled from another plant I had nearby. This leaf was badly infested; there were just a few on the next leaf.
The females can’t fly, so it’s they only way they can get there. Apparently, in the wild they can just get blown in the wind but I don’t think there is enough air current in the house.
Eventually, they can get in enough numbers that they can cause serious damage, so I’m going to have to watch this one closely. Normally, I pick off most, then use soapy water, but the adults have a waxy coat, so I mix in a bit of rubbing alcohol which should dissolve it. This plant is big for a house plant so I won’t be able to move it.
Here is a close-up. While preparing for this, I finally saw one move, just detectable under a 16× lens. You can just see the six legs on the smaller ones. Look how flat they are. The biggest one is about 1mm (1/16″).
I used side lighting on the next picture to give you some idea how little shadow they cast.
If you flip over one of the ones with a hard, waxy shell, you see they are stuffed full of eggs. It is hard to imagine how the actual insect could fit into the shell with all the eggs, or how what little body it had left could have laid all those eggs. You can see how easy it is to miss the tiny first instars (stages of an insect’s growth) when they hatch from these eggs. Barely visible with naked eye, this is about as much magnification as I can squeeze out of my camera with macro lens and macro tubes combined.