Honeydews are sweet smelling when ripe. The seeds will loosen and can be heard when the fruit is shaken. Watermelons are much more challenging. The underside of the fruit should change colors from white to yellow. A mature melon will also produce a dull thud when thumped.
Tomatoes are a bit of a challenge in our area.
These bugs have sucking mouth parts that leave small, hard brown spots surrounded by yellow blotches. The tomatoes are still edible, but may be slightly less tender or flavorful in those areas. The best way to beat these critters is to pick the fruit at the first signs of maturity. When tomatoes begin to slightly change color from green to a yellowish-orange, take them off the vine and finish the ripening process inside, safe from the insects. They don't have to be on a windowsill.