locustShadow

The shadow a locust cloud drags across the crop: a ground-hugging disc that is solid through the middle and frays at the rim, with the fray turning slowly on two harmonics so the patch moves like a cloud of insects rather than sliding like a decal. Its size and smear follow the swarm's radius and how high it is flying, so a cloud down in the wheat lays a tight dark patch and one at travel altitude throws a long soft one.