Encarsia for the win!

The black dots on this leaf are pupae of Encarsia formosa, and are ready to hatch and immediately host feed and parasitize the greenhouse whitefly (Trialeurodes vaporariorum) population they are nestled into.

At first glance, it may not seem like enough but the timing here is key. The lifecycles of greenhouse whitefly and Encarsia overlap in such a way that first the adult whitefly will emerge from their pupae, and then shortly after (~ 7 days) the Encarsia adults will emerge from their pupae.

This separation in timing can cause panic when at first it appears that whitefly numbers have increased. Hang in there! That is only the first half of the equation and Encarsia has a solid response.

The delay in Encarsia’s emergence time, in fact, allows for Encarsia to hatch to a population of whitefly that is at the right stage for immediate host feeding. Encarsia can host feed on the buffet of early stage (L2) whitefly larvae surrounding them, boosting fecundity, and then proceed to parasitize any remaining late stage (L4) whitefly larvae.

Once this pattern of biocontrol is in place pest populations don’t stand a chance, and Encarsia’s overall faster lifecycle will take over.