Rhyzopertha dominica (Coleoptera: Bostrichidae) infestation on seeds of Sorghum drummondii (Poaceae) in packages sold in retail stores

Abstract

ABSTRACT Insect damage to stored seeds is a challenge. Rhyzopertha dominica (Fabricius, 1792) (Coleoptera: Bostrichidae) is a major pest of seeds and grains in the world, but without record in seeds of the sudangrass (Sorghum drummondii (Poaceae)). The objective of this work was to report, for the first time, the occurrence and damage by R. dominica in S. drummondii seeds, sold in sealed packages in retail market. Four samples with 500 seeds each and without adult insects were separated from a package. The initial weight was obtained with a precision scale and the seeds were stored. The number of adult insects, the weight loss and the infestation rate of the seeds were evaluated 60 days later and the average between samples used to extrapolate the damage per package. An adult of R. dominica, on average, was obtained for each seven seeds and 54.06% of the seeds were damaged, with an average weight loss of 36.09%. This is the first report of R. dominica in sudangrass seeds and the damage inflicted shows that this insect may cause losses in the quantity and quality of seeds due to its rapid populational growth.