The culprit may not be a tomato hornworm or grub
The culprit may not be insect-related but instead something bigger but just as persistent: birds.
Many bird species have a varied diet that includes fruits, and tomatoes can be attractive to them due to their bright color and juicy texture. They eat tomatoes for the food and also for hydration.
While some birds may peck at tomatoes to eat them, others may do so out of curiosity or playfulness.
Keep in mind that birds are not the only animals that may be interested in tomatoes. Other creatures like squirrels, insects, and small mammals may also take a bite or peck at ripe tomatoes when given the opportunity.
Before you employ any of the protection strategies below, make sure you’ve correctly identified the culprit. Ripe tomatoes are the target of many pests, but bird damage leaves a particular mark.
When birds feast on your tomatoes, they aim to reach the juicy, hydrating inner pulp. The tell-tale sign of bird damage is a fairly large, deep hole that looks like it was created by pecking. Picture your tomato being stabbed by a beak because that’s exactly what happened.
Before you employ protection strategies, make sure you’ve correctly identified the culprit. Ripe tomatoes are the target of many pests, but bird damage leaves a particular mark.
How to protect tomatoes from birds
Physical barriers, distractions, and scare tactics are all proven ways to prevent birds from eating your tomatoes, and all three are affordable, accessible, and easy to implement.
To protect your tomato plants try installing bird netting, shade netting, fake scarecrows, or reflective objects to deter them. Or hang a wind-chime(s) nearby to scare the birds away.
Additionally, picking tomatoes as soon as they ripen and not leaving overripe ones on the vine can reduce the attraction for birds and other creatures.
Here's an informative article on 8 kinds of birds that like tomatoes.