One end of the fruit rots making it unuseable. A calcium deficiency is the cause of this disorder. Try spraying 2 times a week with 4 tablespoons of calicium chloride mixed in 3 gallons of water. Spray 1 quart per plant. The most annoying part of growing vegetables is coping with pests and diseases.
Insecticidal soap is useful for sucking insects.
Follow label directions and spray on the underside of the leaves before 10 a.m. Never spray if pollinating bees or wasps are working the flowers. Beneficial nematodes kill many soil-borne insects, including cutworms and beetle and weevil larvae that can chew foliage and roots of many plants, including tomatoes. Spray them in the garden with a hose and water. It's an organic specific stomach poison for use on caterpillars such as hornworms and fruitworms.