On a recent trip back to New Zealand, Zespri’s Japan supply manager Bryan McGillivray shared insights on the spread of Psa and other unwanted pests in Japan with Zespri colleagues and KVH.
Bryan said, since Psa3 (the previously called Psa-V) arrived in Japan in 2014, it developed and spread through the Japanese kiwifruit industry as it did here. Climatic differences such as Japan’s hotter summers had reduced the pace of the spread of Psa somewhat. Of Japan’s 2,177 hectares of kiwifruit, around 69% is now infected with Psa3.
As in New Zealand, Hort16A has been most affected by the Psa and blocks are being removed as they become uneconomic. Southern areas of Japan remain free of Psa and movement controls are in place to help protect orchards.
Some potential biosecurity threats to New Zealand are already present in Japan providing an opportunity to learn how growers manage these pests and what else should be on our radar as emerging risks to our industry. The Brown Marmorated Stink Bug (BMSB) is one such example, a pest of significant concern to us, yet in Japan where it is native, impacts do not seem to be significant.
This is thought to be because the samurai wasp is also native to Japan, and parasitises BMSB eggs keeping populations in check. The good experience from Japan tells us this could be an effective control tool to have so KVH and other horticultural industries are seeking pre-approval to release the samurai wasp as a biocontrol agent should BMSB ever establish here.
KVH has an information-sharing relationship with Bryan’s team in Japan, which will ensure both organisations stay abreast of pest developments and potential new research opportunities across the two countries.