This might look like an aerial view of a new subdivision but it's actually a leaf mine in a seedling big-tooth poplar, Populus grandidentata, leaf. Besides the apparent architectural similarity, what I find fascinating about this photo is that you can follow the entire larval life history of this insect, be it a fly, a moth (most likely) or a sawfly. Starting at just about the middle of the right hand side of the photo you can see where the life-track begins. Shortly after hatching the larva moulted then you can follow it's gustatory journey up to the top right corner of the photo where, constrained by the leaf veins, it has to turn left and shortly afterwards moults again. You can see it's entire journey, through four moults, each successively longer than the last as the larva grows, to the present time (at least to the time I took the photo at Roaches Pond on August 14th), to where the caterpillar has eaten itself into a corner near the lower left of the photo. Don't you just hate when that happens?