Long-term efficacy of diatomaceous earth, SilicoSec® against three major stored grain insect pests

Abstract

Diatomaceous earth (DE), which possesses low mammalian toxicity and stability on grain, has promising potential in controlling stored grain pests. However, only a few published studies focus on the effectiveness during the long term storage. The current study assessed the long-term efficacy of DE, SilicoSec® on Sitophilus granarius, Rhyzopertha dominica, and Tribolium confusum using infestation with two adults per kg of wheat. The population density of each pest was monitored throughout one year in 50 kg of stored wheat treated with three doses of SilicoSec® (500, 1000, and 2000 mg/kg grain) in drums under laboratory condition. The number of adults (dead or alive) for S. granarius, R. dominica, and T. confusum was 8.00 ± 1.73, 2.00 ± 0.58 and 1.00 ± 0.58, respectively, at 2000 mg/kg dose of DE by 12 months of storage. The suppression rate was 95.2, 99.4, and 97.9% for S. granarius, R. dominica, and T. confusum, respectively, at 1000 mg/kg DE after 12 months of storage.

This study showed that wheat treated with SilicoSec® at 1000 mg/kg could be satisfactorily protected against major stored grain pests for a year. SilicoSec® has great residual efficacy for a year, which is generally not achievable with residual grain protectants.