Integrated Application Demonstration of Spinosad for Grain Storage Pest and Mould Control

I. Project Overview

Currently, China experiences an annual loss of 35 million tons of grain in storage, transportation, and processing stages, accounting for over 10% of the total grain production. Pests and moulds are the primary factors threatening grain storage safety and causing significant losses. To combat this, China has long been overusing the highly toxic chemical fumigant aluminium phosphide, leading to increasing pest resistance, heightened control difficulties, and prominent environmental and safety hazards. Addressing these issues, the COFCO Nutrition and Health Research Institute Co., Ltd. has researched the application of the green biological pesticide spinosad in real warehouse scenarios, demonstrating its integrated application in grain storage and logistics.

II. Approaches

Spinosad, also known as spinosyn, is a macrocyclic lactone biopesticide extracted from the fermentation broth of Saccharopolyspora spinosa. It exhibits rapid contact and ingestion toxicity to storage pests by stimulating their nervous system, increasing spontaneous activity, leading to non-functional muscle contractions, exhaustion, and subsequent tremors and paralysis. Spinosad is effective in controlling a variety of storage pests such as rice weevils, maize weevils, granary weevils, red flour beetles, Indian meal moths, wheat moths, mites, flour moths, and purple-streaked grain moths.

In the grain storage stage, to address the issues of high labor intensity and low efficiency in manual pesticide application, an automated pesticide application device for grain storage was developed with the support of relevant departments. Spinosad's surface application technology was trialled in 6 grain depots across 5 provinces in COFCO's Yangtze River and Coastal Regions, involving 13 test grain silos and totaling 70,000 tons of policy reserve grain (rice, wheat, corn). The results were compared with other storage protectants. It was found that in moderate temperature and humidity regions, the effective protection period of surface-applied spinosad exceeded one year. In high temperature and humidity regions, its efficacy was superior to phosphine and cypermethrin.

Addressing the issue of high safety risks and long processing times in the use of aluminium phosphide fumigation under poor sealed conditions in logistics warehouses for feed grain, emergency pest control trials with spinosad were conducted. For corn and rice mixtures meeting severe pest standards, a dose of 3g/t of spinosad applied throughout the warehouse upon entry using automatic dispensers and a 7-day treatment effectively killed storage pests, achieving standards of virtually pest-free grain.

In the grain logistics stage, to address economic losses such as returns and delays caused by the inability to fumigate grain with aluminium phosphide during high temperature periods on Yangtze River grain barges, pest control trials with spinosad were conducted on 10 barges travelling from the Yangtze River Estuary to upstream destinations like Chongqing, Changsha, and Nanchang, covering 30,000 tons. For virtually pest-free grain, a dose of 1g/t of spinosad was applied to the surface using drones after loading. For general and severely infested grain, 2-3g/t of spinosad was applied at multiple intervals during loading. The trial barges, which travelled for 7-15 days to port and until unloading (30-40 days), showed no live pests, demonstrating significant control efficacy.

III. Project Benefits

Based on the results of the spinosad application trials, COFCO Nutrition and Health Research Institute Co., Ltd. established the first domestic group standard for the application of biological grain storage protectants, "Technical Procedures for Spinosad Control of Storage Pests", laying the foundation for further promotion and application of spinosad in grain storage and transportation, and providing strong support for grain conservation, loss reduction, and food security in storage and transportation.

Source from: 

National Food and Strategic Reserves Administration