عنوان مقاله [English]
This insect belongs to primitive insects (order Collembola) called springtails. They are usually characterized by a special organ on the underside of the body enabling them to jump. The species living on sugar beet roots (probably Onychiurus spp.) are usually white and about 2-4 mm. long. They live in the soil, produce minute, rounded pits which turn dark rapidly after feeding. Seedlings may be killed before and at emergence, or their growth may be stunted as a result of the damage. This kink of damage is similar to fungus damage or sugar beet flea beetle. There was a low population density of these insects on roots and collar of seedlings in Motahary research station this year. They are more active in soils rich in organic materials or animal manure. When ever numerous on the main root or collar of a tiny seedling, they become dangerous. Besides of their damage by feeds, they provide entry points for pathogenic fungi.