[realsimple.com:] Cantaloupes often contain five of the longest-lasting chemicals, one of which is dieldrin, an exceedingly toxic and carcinogenic insecticide. Though it was banned in 1974, residues still persist in soils and are taken up through the cantaloupe's roots and absorbed into the edible portion.
[Huffington Post:] Cantaloupe That's a hard shell cantaloupes boast, so non-organic is fine for this melon. To err on the side of caution, though, you might want to avoid cantaloupes from Mexico, where they can be heavily sprayed by pesticides.)
Realsimple.com asserts 'yes'; please notice that I ask this question for all melons (eg: honeydews, watermelon, etc...) and not only cantaloupes.