The most common flour bugs are the confused flour beetle, which has the scientific name Tribolium confusum, and the red flour beetle, known scientifically as Tribolium castaneum. The tiny, 3-millimeter long beetles are difficult to tell apart without a magnifying glass.
The white eggs of the confused flour and red flour beetles are nearly undetectable to the human eye. By the time an infestation is discovered, the beetles have generally reached full maturity.
Another kitchen pantry pest is the Indian meal moth, or Plodia interpunctella. Although less common in white flour products than the confused flour beetle and the red flour beetle, the Indian meal moth infests other pantry products such as dry pet food, whole grain flour and cereal. The Indian meal moth is 1/2 inch long and is easy to detect, as it often escapes its confines and flutters about.