Ethyl formate fumigation against pineapple mealybug, Dsymicoccus brevipes, a quarantine insect pest of pineapples

Authors: KWON, TAE-HYUNG - Oak Ridge Institute For Science And Education (ORISE); KIM, DONG-BIN - Kyungpook National University; KIM, BONG-SU - Animal And Plant Quarantine Agency; BLOESE, JOANNA - University Of Hawaii; LEE, BYUNG-HO - Kyungpook National University; Cha, Dong

Submitted to: Insects
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/29/2023
Publication Date: 1/2/2024
Citation: Kwon, T., Kim, D., Kim, B., Bloese, J., Lee, B., Cha, D.H. 2024. Ethyl formate fumigation against pineapple mealybug, Dsymicoccus brevipes, a quarantine insect pest of pineapples. Insects. 15(1). Article 25. https://doi.org/10.3390/insects15010025.
DOI: https://doi.org/10.3390/insects15010025

Interpretive Summary: Pineapple mealybug is a major pest of pineapple production and key trade barrier. Methyl bromide fumigation (MB) has been generally used to disinfest imported pineapples. However, its use has been being phased out due to its impact on ozone layer and human health. As a first step to develop MB alternative treatment for imported pineapples, researchers at the USDA-ARS and University of Hawaii in HI, and Kyungpook National University and Animal and Plant Quarantine Agency in South Korea are testing whether ethyl formate (EF) fumigation is effective for the disinfestation of pineapple mealybugs from pineapples. In a scale-up trial, EF fumigation was effective at controlling pineapple mealybugs without negative impact on pineapple quality, suggesting EF fumigation as a potential disinfestation treatment for pineapple mealybugs in imported pineapples.

Technical Abstract: Pineapple mealybug, Dysmicoccus brevipes (Hemiptera: Pseudococcidae), is a significant pest in pineapple production and a key trade barrier. We explored the potential use of ethyl formate (EF) as a methyl bromide alternative for the postharvest fumigation of D. brevipes in imported pineapples. When treated at 8' for 4 h, EF fumigation was effective against D. brevipes with LCt99, the lethal concentration x time products of EF necessary to achieve 99% mortality, of D. brevipes nymphs and adults at 61.2 and 134.8 g h/m3, respectively. Sorption trials conducted with 70 g/m3 EF for 4 h at 8' using 7.5, 15 and 30% pineapple loading ratios (w/v) indicated that the loading ratio lower than 30% is necessary to achieve the LCt99 values required to control D. brevipes. In a scaled-up trial (1 m3), EF fumigation with 70 g/m3 for 4 h at 8°C with 20% pineapple loading ratio (w/v) resulted in a complete control of D. brevipes treated. There were no significant differences in hue values, sugar contents, firmness, and weight loss between EF treated and untreated pineapples. Our results suggest that EF is a promising alternative of methyl bromide fumigation for the postharvest phytosanitary disinfection of D. brevipes in pineapples.