Synergistic ozone and predatory bug approach for stored product pest control

Overview

This research investigates an integrated pest management strategy that combines ozone gas treatment with biological control using the predatory warehouse pirate bug (Xylocoris flavipes) to combat stored product insect pests. Current research has primarily focused on individual control measures, which often fail to provide complete pest suppression. This work addresses a critical gap by examining whether combining ozone at specific concentrations with targeted predatory bug densities produces synergistic effects that enhance overall pest control.

The proposed solution targets three major stored product pests: the merchant grain beetle (Oryzaephilus mercator), the cigarette beetle (Lasioderma serricorne), and the rice weevil (Sitophilus oryzae). Both control methods are safe for humans and the environment, making this approach suitable for food storage facilities, warehouses, and grain handling operations where chemical pesticide use is restricted or undesirable.

Technical specifications

Ozone treatment parameters:

• Concentration range: 100–400 ppm at 50 ppm increments
• Exposure duration: 1–6 hours at 100 ppm for surface treatments; 12–60 hours for insects within wheat substrate
• Demonstrated mortality rates of 25–50% at 200 ppm across all species and life stages
• Egg stage identified as the most ozone-tolerant developmental phase

Predatory bug (PB) parameters:

• Density range: 0–4 previously starved adult PB per 300g food substrate jar
• Documented suppression of insect pest populations by 50–80% when used independently
• Assessment period: 2 days for larvae, pupae, and adult mortality; 7 days for egg survivors

Key factors influencing efficacy:

• Ozone concentration and exposure time
• Insect developmental stage
• Food availability during treatment
• Depth of insects within grain substrate
• Gas loss during treatment

Analytical methods: Dose-mortality response analysis, ANOVA, and Probit analysis to determine optimal combinations achieving 100% mortality across all life stages.

Technology readiness level

The ozone treatment component has been validated through prior studies confirming effectiveness against all developmental stages of the three target pest species. The biological control component using predatory warehouse pirate bugs has established literature support for population suppression. The synergistic combination approach is currently in the experimental validation phase, with planned studies to determine the optimal ozone concentration and PB density combinations needed to achieve complete mortality across all insect life stages. The research team has secured project funding for the ozone generator and necessary supplies to conduct these validation experiments.