antenna butterfly England forewing hindwing insect Lepidoptera little nature orange rest rhopalocera skipper small small skipper summer Surrey Thymelicus sylvestris tiny wing animal Centaurea feed feeding flower flowerhead knapweed proboscis suck sucking Sussex Thymelicus tongue wild brisling bristling calcium can canned clupeidae edible European-sprats fatty-acids fish food golden health healthy heart-healthy herring-family herring-like marine-fish nonperishable nutrient-rich nutrients nutritious oil oily-fish omega-3 packed polyunsaturated portable potential self-contained-food smoked sprats sprattus-sprattus tightly-packed tin tinned tins vitamins can-opener accessible crammed European-sprat open opened pilchards sardines silvery skin sprat tight