Say hello to the family Neriidae—commonly known as cactus flies or banana stalk flies—a group of ultra-slender, long-legged true flies that live exclusively in tropical zones. When it comes to the sexes, these flies exhibit intense sexual dimorphism. Males sport heavily elongated bodies, longer legs, and noticeably larger heads and antennae compared to females. Those ridiculously long forelegs aren’t just for show, either; males use them to wage epic wrestling matches against rivals over breeding territories. They will literally entwine their limbs and put each other into headlocks until the loser is forced to retreat! While the adults aggregate in large numbers near floral nectar or sap, their larvae are the ultimate recycling crew, thriving entirely inside decaying cacti, rotting fruit, or dead bark where they eventually pupate. I came across a nice female likely belonging to the genus Glyphidops deep in the protected forest of La Perla, Ecuador.