Look for Cutworm droppings. They look like miniature rodent feces droppings and can be found on foliage as well as the ground, you'll need a keen eye to spot them, but they are visible.
Handpicking cutworms off your plants at night is feasible. You'll need a light source, then simply pick them off and squash the little buggers, a bug genocide. You can also place them in a pail of soapy water to drown. You'll need to repeat this a few times weekly. Even if you think you have them beat you should keep checking throughout the season for a reemergence.
Cutworms will eat plants by chewing near the plant base through the stems, Placing barriers around the stems will slow them down, and in most cases stop them.
Cardboard tubes from paper towel or toilet paper rolls work for this, but tend to disintegrate after repeated rain and watering. Plastic bottles or metal cans with the ends cut off work even better.
Sprays/Pesticides must be applied in the pre bloom stage to prevent injury. Pesticides such as Pyrethins and derivative products, are more effective in cool rather than warm weather will work more efficiently against Fruit worms earlier in the season, and is the recommended early season chemical treatment for most worms.
Proper sanitary practices are vital to the health of your garden. Proper sanitation can help to ensure disease-free pest-free and productive gardens. Try to keep the garden free of any diseased dead or damaged plant materials. Remove cuttings from pruning and trimming and either destroy them - if diseased, or send them to the compost pile. Leaving rotting fruits and vegetables in the garden is like a written invitation to unwanted pests and diseases.
If a diseased or dead plant part has to be cut, the microorganism that caused the problem is probably on the tool you just used. Like a surgeon, sterilize all tools by washing in soap and water - rubbing alcohol wouldn't hurt either. If you pinch off diseased plant parts, wash hands before handling any other plants. Keep Weeds under control. Till the soil in the spring before planting to expose and kill larvae that wintered over in the soil.
Diverse gardens that include a symbiotic mingling of flowers and vegetables are a poor environment for insect pests as they also attract many natural predators, Lacewings and Ladybugs in particular. Praying Mantis will prey on the moths. Adult moths can be trapped with light traps by night. Beneficial Nematodes are useful against cutworms as They hide under the soil surface during the egg and larva stages.