Melon Pest - Vinegar Fly
Content from UC IPM: http://www.ipm.ucdavis.edu/
DESCRIPTION OF THE PEST
Vinegar flies, also known as fruit flies, are small, tan to amber-colored flies with red eyes, about 0.12 inch (3 mm) long. Larvae are small, white, legless maggots that get up to 0.2 inch (5 mm) long. They differ from dried fruit beetle larvae in that they do not have a hardened head capsule.
Damage is similar to the dried fruit beetle in that the presence of vinegar flies in fruit causes downgrading or rejection of fruit. Vinegar flies are also responsible for transmitting spoilage organisms to sound fruit. Late ripening varieties are especially susceptible to damage as vinegar flies become widespread in tremendous numbers.