I decided to buy these http://www.ebay.co.uk/itm/Nemasys-leatherjacket-killer-lawn-pest-foxes-damage-grass-daddy-long-legs-birds-/151246148182
because they promise delivery next week.
But they are expensive (£20), worth it for my salad sales but a frustrating price for growing veg to eat. I shall use them only where growing lettuce, spinach, beetroot and chard which so far are chief victims. Alliums and brassicas look alright.