This is a charade - two separate parts are joined together to form the answer.
Look for a winged insect, then think about what you call the end or extremity of something. These two parts combine to give you a term for illegal dumping.
Answer: FLY-TIP | A FLY is an insect, and TIP is the end of something. Together they make FLY-TIP, meaning to illegally dispose of waste.