TomatoesNZ provides funding for study of Tamarixia in glasshouses

The TomatoesNZ board approved a funding contribution for a Lincoln University post-doctoral student to undertake some research on the use of Tamarixia, the new Tomato and Potato Psyllid (TPP) biocontrol agent, in glasshouses.
 

Tamarixia is a small wasp that is a parasitoid of TPP. Tamarixia will actively seek out and target TPP within solanaceous crops and lay its eggs on the TPP. Once hatched, the Tamaraxia larva will consume the TPP nymph. Tamarixia is found naturally in North America and Mexico – where TPP is also found.
 

There is a belief that Tamarixia may not be useful in a glasshouse situation because biological control requires a base level population of the pest for sustenance, and growers have a “zero tolerance” for TPP.  Additionally there is the fear of introducing a Liberibacter infection, vectored by the TPP.
 

However, the Lincoln research group believe that Tamarixia could reduce pest numbers by 99.9%. There is also some recent NZ research showing that almost all wild TPP are not carrying Liberibacter, but instead the bacteria load increases following it’s colonisation of crops.  The post-doctoral study will look at whether Tamarixia can achieve and maintain low populations of TPP in the glasshouse, and the impact on Liberibacter presence.
 

At the time of writing this column, no Tamarixia had yet been released into NZ. As reported in last month’s column, the first imported batch were found to have a fungal contaminant. It is hoped that some “clean” Tamarixa will be available for release in the next couple of months.