Lethal temperature for pinewood nematode, Bursaphelenchus xylophilus, in infested wood using radio frequency (RF) energy

Abstract

We evaluated radio frequency (RF) dielectric heating for eradication of pinewood nematodes (PWN) in infested wood. Thirteen temperatures were tested (from ambient to 70 °C) on small wood samples (2.5 9 3.8 9 0.64 cm) to determine the minimum lethal temperature (100 % mortality), which was 56 °C [based on infra-red (IR) thermal images data 55.5-57.4 °C] with a 1 min hold time. We also used thermal probes inside the wood to confirm that temperatures were C56 °C. Thirty additional samples were tested bracketing the minimum lethal temperature using 54, 56 and 58 °C with additional replications to produce the minimum sample size equivalent of 100 % mortality of at least 93,616 nematodes to satisfy the Probit 9 efficacy requirement. This minimum lethal temperature was further verified by treating infested large wood blocks (10.2 9 10.2 9 25.4 cm). All samples that met or exceeded the 56 °C lethal temperature for the required 1 min hold time (as measured by probes inserted in the wood and on the wood surface by IR) produced 100 % mortality. The sample size required to show Probit 9 efficacy was also satisfied. This study supports the consideration of RF in addition to microwave (MW) dielectric heating as alternative treatments of wood packaging material for inclusion in ISPM No. 15, provided the treatment delivers the target lethal temperature throughout the profile of the material in industrial scale operations.

Calentamiento por radiofrecuencia para esterilizar Pinus radiata como material para embalajes. Parte 1: Tiempo total de tratamiento

“…La radiofrecuencia es recomendable para maderas gruesas ya que la penetración es profunda, pero relativamente lenta. Diversos autores han demostrado las condiciones de aplicación de radiofrecuencia (combinaciones de temperatura, espesor o diámetro, tiempo y tipo de ambiente) para que puedan ser eliminados de la madera hongos, insectos y nematodos (Dwinell 1997, Petrič et al 1998, Fang et al 2001, Watanabe et al 2011, Tubajika et al 2007, Lazarescu et al 2015, Lazarescu et al 2009, Uzunovic et al 2013, Dubey et al 2016, Zhao and Wang 2018.…”

“…Ciertos problemas con la uniformidad de la temperatura en el interior de la madera han sido observados Avramidis 2012, Dubey et al 2016). La aplicación del calentamiento por radiofrecuencia a 56 °C por 30 minutos ha demostrado ser letal para los nematodos (Uzunovic et al 2013).…”

Efficacy of three different steamers for control of bed bugs (Cimex lectularius L.)

“…As one of the non‐chemical control methods, heat treatment is currently used for control of stored food product pests as well as wood‐destroying pests . Bed bugs are sensitive to high temperatures; thus, heat treatment has been applied as a practical and effective means of bed bug control .…”

“…3,7 As one of the non-chemical control methods, heat treatment is currently used for control of stored food product pests 8,9 as well as wood-destroying pests. [10][11][12] Bed bugs are sensitive to high temperatures; thus, heat treatment has been applied as a practical and effective means of bed bug control. 2 Pereira et al 13 reported that mortality of bed bug adults started at 41 ∘ C with an exposure time of 100 min, and this time gradually decreased as the temperature increased, to about 1 min at 49 ∘ C. Johnson 14 demonstrated that all stages of bed bugs are killed after exposure to 45 ∘ C for 1 h. The target heat treatment temperature used for killing bed bugs by the professional pest management industry is between 45 and 52 ∘ C. [15][16][17] Heat can be applied via hot laundering/drying of infested clothing and bedding, 18 and through the use of portable heat chambers or structural heat treatments.…”

Ultrasonic phytosanitation of pinewood nematode infected wood

“…Thus, there is significant need for new non-chemical based alternative treatments. Dielectric heating both a radio and microwave frequency levels was tested with positive results for green logs, timbers and packaging materials thus leading to its adoption as substitute treatment (Lazarescu et al 2010, Hoover et al 2010, Uzunovic et al 2013, Lazarescu et al 2015.…”