{'fraction_non_alphanumeric': 0.02283653846153846, 'fraction_numerical': 0.019230769230769232, 'mean_word_length': 4.821678321678322, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Eradication of eucalyptus weevils in apples by ethyl formate

Export of Pink Lady™ apples from Australia have been significantly affected by infestations of adult eucalyptus weevil (eucalyptus snout beetle or gum tree weevil). These weevils do not damage apple trees or fruit, but rest at the petiole portion of apples when selecting overwintering sites. As a result apples infested with live eucalyptus weevils leads to rejection for export. Usage of methyl bromide as post harvest treatment is restricted under the Montreal Protocol. Therefore, it has become important to develop an alternative safe fumigant as an eradication method for eucalyptus weevil on apple. Laboratory experiments were conducted to evaluate ethyl formate, which is a naturally occurring volatile chemical present in many plant commodities, as fumigant for eradication of the eucalyptus weevil on apples. Laboratory and cool storage trials show that ethyl formate is highly toxic to the eucalyptus weevil and low phytotoxic to the fruit. Complete control can be achieved at 30 g m-3 of ethyl formate at 25oC for 24 hours exposure with and without apple. In comparison with untreated apples, the colour and texture have no change 1, 2 and 3 weeks after treatment. Four field trials were conducted in cool storages (the capacity ranged from 250-900 tonnes) in Western Australia. The ethyl formate was applied at dosage of 50-55 g m-3 and low temperature (4-8oC) for 24 hours exposure. All eucalyptus weevils were killed and after 1 day aeration, residue of ethyl formate declined to natural levels (0.05-0.2 mg kg-1). Phytotoxicity studies showed no effect on morphology or taste of apples.