Synergistic effects of heat and diatomaceous earth treatment for the control of Plodia interpunctella (Lepidoptera: Pyralidae)

Abstract

Plodia interpunctella is a major economic pest that commonly infests most stored and processed agricultural products. Currently, heating at 50–60°C for at least 48 h is applied in facilities for disinfestation. However, this condition requires a great deal of time and expense. To improve the control efficiency of this system, we conducted combined treatments with heating and diatomaceous earth (DE), which is known to be toxic to pest insects. The DE effect was compared to heating at 25°C or 40°C to wandering fifth instar larvae, which is the stage most tolerant to heat. When larvae were brushed with DE powder, mortality was only 15.0–18.3% at 25°C for 10 days, but rapidly increased to 100% at 40°C within 4 h post‐treatment. In addition, when larvae were kept in a plastic cage with DE [4 mg/L (w/v)], their mortality was 100% in 24 h at 40°C post‐treatment; otherwise mortality was only 8.8% without DE. Thus, the control efficiency of heating significantly improved with the combination of DE. These effects increased further at higher temperatures and with longer exposure. Our results clearly showed that DE treatment showed synergistic effects with heating systems for the control of P. interpunctella.

Effects of gamma radiation on different developmental stages of the oriental tobacco budworm, Helicoverpa assulta (Lepidoptera: Noctuidae)

“…Among several other alternatives such as heating, cooling and combination with other methods (e.g., Kim et al 2014) ionizing radiation is considered an alternative quarantine treatment for controlling pests (e.g., Balock et al 1966;Hallman 2000). Although ionizing radiation has been reported to decrease the freshness of products and to expedite the softening process in fruits and vegetables, causing a deterioration in taste (Strydom & Whitehead 1990;Gloria & Adão 2013), low doses of ionizing radiation (e.g., 1 kGy) are still permitted for disinfestation of foodstuffs and for quarantine and phytosanitary purposes by the US Food and Drug Administration (Kader 1986;Morrison 1989).…”

Differential induction of heat shock protein genes to the combined treatments of heat with diatomaceous earth, phosphine or carbon dioxide on Plodia interpunctella

“…For example, the combination of heat (30-36°C) and CO2 (3-7%) allows for complete insect control within 24-36 h, with a concentration of PH3 of only 80-100 ppm (Fields & White 2002). Our previous study proved that the complete mortality of wandering larvae of Plodia interpunctella could be achieved within a 12 h exposure to various amounts of DE while heating (Kim et al 2014).…”

“…Our previous study proved that the complete mortality of wandering larvae of Plodia interpunctella could be achieved within a 12 h exposure to various amounts of DE while heating (Kim et al . ).…”

Molecular cloning and expression analysis of a myosin light chain 1 (MLC‐1) gene from Indian meal moth Plodia interpunctella (Lepidoptera: Pyralidae)

“…The larvae feed on various dry foodstuffs such as corn, grains, nuts, dried fruit and chocolate (Kim et al . ). However, only few genes had been reported and characterized in P. interpunctella (Aye et al .…”

“…The Indian meal moth, P. interpunctella (Lepidoptera: Pyralidae), is a major pest of stored grain and grain products. The larvae feed on various dry foodstuffs such as corn, grains, nuts, dried fruit and chocolate (Kim et al 2014). However, only few genes had been reported and characterized in P. interpunctella (Aye et al 2004;Liu et al 2015a).…”