Investigating the feasibility of shortduration hot water treatments for apple disinfestation

Abstract

The presence of live pests on packed apples is a concern for many of New Zealands export markets Greedy and latania scale onion thrips apple leafcurling midge (diapausing larvae) and obscure mealybug were subjected to hot water treatments (HWT) of 495 510 or 525C for either 1 2 or 3 min Latania greedy scale and onion thrips were the most susceptible pests to HWT with either 23 min at 495C or 8805; 1 min at 510 or 525C achieving >80 mortality HWT of 525C for 13 min consistently achieved >90 mortality of apple leaf curling midge diapausing larvae Obscure mealybug was the most tolerant species tested with mortalities of 6070 at 510 or 525C for 2 or 3 min A HWT of 51C for 2 min did not affect quality of Royal Gala Fuji and Braeburn apples There is potential for shortduration HWTs to achieve high mortalities of a range of insects while resulting in minimal damage to apple fruit