Cocoa tree (Theobroma cacao) developing fruit. In nature, cocoa trees are entomophilous - meaning they require insects to pollinate them. Theobroma cacao is pollinated by tiny flies in the Ceratopogonidae family of flies (commonly known as no-see-ums). In the greenhouse they have to be hand pollinated.
This reminds me of a Magic Schoolbus episode "In the Rainforest" where the well meaning manager cleans up the area around his stand of cocoa trees to eliminate mud and annoying peccaries which in turn eliminates pollinators and thus his trees don't produce any cocoa beans. Of course, the kids in Ms. Frizzles class solve the mystery of the fruitless cocoa trees and all is well in the end.












