10 th International Working Conference on Stored Product Protection Julius-Kühn-Archiv, 425, 2010 359 New prospects for Ethyl formate as a fumigant for the date industry Finkelman, S. *# 1 , Lendler, E. 2 , Navarro, S. 1 , Navarro, H. 1 , Ashbell, G. 1 1 Food Technology International Consultancy Ltd., P.O. Box 3300, Beit Yehoshua, 40591, Israel. Email: Finkelman@ftic.info 2 Agriterra Ltd., P.O. Box 1071, Haifa Bay, 26110, Israel. * Corresponding author # Presenting author DOI: 10.5073/jka.2010.425.167.136 Abstract Date infestation of nitidulid beetles poses a serious contamination problem for which methyl bromide (MB) provided a solution. However, because of the phase out of MB, alternatives were investigated. Thermal disinfestation method has been successfully applied to some dry date varieties except to Deglet- Noor, Zahidi, and Ameri which are handled in crates of 200 kg to 400 kg. Therefore, thermal disinfestation was not successful because of delayed heating due to the resistance of the dates to hot airflow. The fumigant formulation Vapormate TM was tested as alternative to MB for the disinfestation (proportion of insects found outside the feeding sites) and control of nitidulid beetles from artificial feeding sites at laboratory and for dates in crates at semi-commercial conditions. Vapormate TM contains 16.7% ethyl formate mixed with carbon dioxide. At laboratory conditions the effect of various dosages of Vapormate TM was tested at 30 o C and at fixed exposure time of 12 h. Exposure of infested artificial feeding sites by larvae of Carpophilus spp. to the concentration of 280 g m -3 of Vapormate TM caused 69.3% disinfestation and 79.9% mortality, 350 g m -3 resulted in 72.7% disinfestation and 98.8% of mortality and the optimal results were obtained at 420 g m -3 that caused 69.6% disinfestations and 100% mortality. Commercial pilot-plant tests were carried out by applying 420 g m -3 Vapormate TM for 12 h in a 9 m 3 flexible liner made of laminate composed of polypropylene/aluminum/polyethylene to cover crates containing infested dates. Disinfestation was tested on naturally infested dates that resulted in an average 100% disinfestation and 95% mortality, while with the artificially infested dates, disinfestation was 97% and mortality 96%. In a second series of tests, a commercial rigid fumigation chamber of 95.6 m 3 was used. After 12 h exposure, 100% mortality was recorded in all date samples. Following the promising results, Vapormate TM was registered in Israel for use by the date industry as an alternative to MB. Keywords: Date, Nitidulid beetles, Ethyl formate, Vapormate TM , Fumigation. 1. Introduction Field infestations of nitidulid beetles pose a serious contamination problem of dates that requires their treatment immediately after harvest (Navarro, 2006). Until now, this problem has been addressed successfully using Methyl bromide (MB) because it causes a high proportion of larvae and adults to emigrate from the fruit before they succumb. This emigration phenomenon is associated with the disinfestation effect that leaves the fruit free from insect presence and more important than the toxic effect of the treatment. Since MB, under the terms of the Montreal Protocol, was phased out in 2005 the date industry needed to find alternative technologies to MB. Over the last two years the Israeli date industry has adopted thermal disinfestation to control nitidulid beetles infestation (Finkelman et al., 2006; Navarro et al., 2003; 2004; Navarro, 2006). A constant hot airflow can be achieved only when the dates are handled in trays of 3 kg or boxes containing 13 kg. However, date varieties Deglet-Noor, Zahidi, and Ameri are handled in two types of crates each containing 200 kg or 400 kg dates for which thermal disinfestations cannot be implemented. An option considered was the use of ethyl formate (EF) in its commercial form known as Vapormate™ in existing fumigation chambers. Ethyl formate occurs naturally in orange juice, honey, apples, pears and wine. It is used as a synthetic flavoring agent in the food industry and as fragrances; it is also a GRAS registered food additive. It decomposes slowly in water releasing formic acid and ethanol. Laboratory tests as a fumigant against insect pests of food commodities and field trials on bagged cereals, spices, pulses, dry fruits and oilcakes have been carried out (Muthu et al., 1984). Ethyl formate is currently registered as a fumigant in Australia as ERANOL ® by Orica Chemnet for the elimination of insect pests in packed dried fruits like raisins. It is toxic to storage