What is this and how do I prevent it? So far it's the only one but it's also the first on that plant to ripen. Leaves are fine no signs of any problems. Lots of flowers and tomatoes. First year vegetable garden converted from a strawberry garden, which was lousy with grubs / June bugs. When I first cleaned up the garden the soul was rich and dark, tons of worms. But then little ghost flies were present for a Few days (before I planted tomatoes). My cauliflower neighboring this plant did get cabbage loopers also. Haven't added anything to my soil.