Optimizing Metabolic Stress Disinfection and Disinfestation Components to Control <I>Pseudococcus longispinus</I>

Abstract

Metabolic stress disinfection and disinfestation (MSDD) has been demonstrated to effectively control longtailed mealybug, Pseudococcus longispinus (Targioni Tozzetti). Standard components previously used for testing MSDD system included a 30-min physical phase of short cycles pressure changes followed by a 60-min chemical phase using ethanol vapor at 10 kPa. This study investigated the effect of varying the following MSDD components on mealybug mortality: duration of the physical and chemical phases, ethanol concentration, and extent of vacuum during the chemical phase. Mealybug mortality responses were analyzed, and the components were optimized using binary logistical regression to achieve 99% mortality of three life stages of the longtailed mealybug (adults, second- and third-instar nymphs and crawlers). Data indicated that the optimal components to achieve 99% mortality of all life stages were a 30-min physical phase and a 45-min chemical phase with 275 mg/liter ethanol at 30 kPa. Optimized components were obtained using binary logistical regression models. These optimized components yielded a 15-min reduction in total treatment time and a 20-kPa decrease in pressure during the chemical phase. Achievement of optimal insecticidal efficacy required all four MSDD components. Nevertheless, optimization and validation achieved 17 and 22% reductions in duration of treatment time and extent of vacuum, respectively.

Development and Validation of a Quick Easily Used Biochemical Assay for Evaluating the Viability of Small Immobile Arthropods

“…Assessing the viability of immobile organisms usually involves either maintaining them in the laboratory to observe whether or not they continue their development (Zettler et al 2002, Johnson and, observing their response to physical stimulation (Follett 2004, Zulhendri et al 2012, or assessing their turgidity (Barak et al 2009, Morse et al 2009), color (Hara et al 1993), or both (Whiting et al 1998). These approaches have limitations because laboratory rearing is slow and sometimes complex, and morphological assessments require signiÞcant technical skill and time, and can be subjective.…”

Efficacy of ethyl formate as a disinfestation treatment for codling moth (<i>Cydia pomonella</i>) in apples

“…Cycles of expansion and compression (physical phase), in combination with low vapour concentrations of ethanol applied with vacuum (chemical phase), were used to kill arthropods and pathogens. Similar research in New Zealand showed that both the physical and chemical (ethanol) phases were required to ensure high mortality of pests (Zulhendri 2012;Zulhendri et al 2012a;Zulhendri et al 2012b).…”

Disinfestation techniques for major cereals: A status report

“…In this technique, insects, mites, and other biological pests are exposed to rapid compression, and decompression cycles in combination with atmosphere modification and ethanol vapors or any GRAS identified chemicals. It is a rapid quarantine level method that has physical and chemical phases providing biostatic and biocidal effects (Lagunas‐Solar, Essert, Piña, Zeng, & Truong, 2006; Zulhendri, De Silva, et al., 2012). This system and method were patented to Lagunas Solar and Essert (2011).…”

“…Mortality is achieved by cyclic anoxia environment by lowering oxygen concentration and increasing the amount of carbon dioxide, causing the metabolic arrest to the insects, and thereby, hypoxia toxicity occurs. Ethanol is responsible for disrupting and disorganizing phospholipid bilayer of the cell membrane and also affects ATP production by interrupting potassium ions‐stimulated p‐nitrophenyl phosphatase activity (Zulhendri, De Silva, et al., 2012).…”