This two-year trial aimed to explore soft management options for whitefly management in the southern valleys. The drivers of this were, managing the risks associated with sticky cotton and the wider industry impacts that were occurring to neighbouring industries such as horticulture. The first year of the trial focused on the use of oils and detergents as a means of control in a small plot, replicated trial at the Irrigation Research Extension Committee Farm, coupled with sticky trap monitoring and a small area of parastoid wasps, Eretmocerus hayati, released. The results from the first year found that there was no benefit from the use of sticky traps in terms of trying to detect a whitefly population earlier. There was also no significant difference between the detergent and oil treatments.

Second year trial looking at the best soft management options after consultation with the wider growing community in the Whitton region, the project direction was changed to broadscale management of whitefly through a combination of soft pesticide applications, oils and the release of Eretmocerus hayati across a wide area to try and influence populations. Sticky traps where used again to try and detect populations earlier. Once again, the sticky traps proved to be of no benefit in the early detection of whitefly. Higher levels of parasitism were achieved where releases were made as expected but from the data collected it was possible to see that the release of the whitefly parasitoids resulted in higher levels of parasite nymphs and a lower whitefly population by the end of the period. It was also possible to see that other fields on the farm where parasites were released, but not directly released on had spikes in the parasitism levels as well as reduced overall whitefly nymph numbers, consistent with the fields that had the releases. The data collected, shows that there was some success in the use of parasitiods for helping reduce the numbers of viable nymphs. Some of the challenges that we will continue to face going forward, are the need to commit to using the wasps at the start of the season when there is no way of knowing what the end of season pressure will be like, and the issues around getting the wasps due to northern demand. There was also an issue with some growers opting to spray fields early rather than allow the parasitised field run their course so we had to remove some data. Overall, the practice change of heading towards the use of beneficials from this work appears viable and this provides some confidence to the growers that they can offer some level of control.