when harvesting some salad for yesterday's dinner i turned over a spinach leaf to find these eggs. well i assume they're eggs? the piccy is a bit blurry i'm afraid. they're bright green (almost fluorescent) round balls that are spiralled into a perfect hexagon shape. each ball is smaller than a pin head, the whole hexagon is smaller than a 5p coin. it's rather stunning to find it but i am concerned that it may be an unwelcome pest. anyone know what this is?