Encarcia formosa attack only immature white fly called scale by laying their eggs inside the scale- The eggs hatch and feed on the scale, which kills it and turns it black- Ecarsia formosa are parasites of the greenhouse white fly, a pest of many plants in interior plantscapes and outdoor gardens- Encarsia formosa are actually tiny wasps, about the size of a pencil dot, completely harmless to people and pets- Apply by hanging little cards with parasitized eggs attached in your affected plants- SKU: ORC017