Description

Adult sugarcane beetles are hard, shiny black scarab beetles found in seedling corn at or just below the soil level (Photo 5-9). Larvae can be found in mid-season corn through late summer. Larvae are cream colored grubs also found in the soil.

Distribution, damage and impact

Surveys have detected adult sugarcane beetles in southern Arkansas near Pine Bluff and Arkadelphia. The adult produces the major damage. Seedling corn is burrowed into at the base of stems generally at the soil line (Photo 5-10). Plants are weakened and may not fully develop. The greatest threat is in fields recently converted from pastures to corn and in reduced tillage systems with substantial grasses. In Arkansas impact of sugarcane beetle on field corn has been minimal during the last four seasons.

Life History

Adult beetles overwinter in soil particularly in grassy areas. With warm spring temperatures, adults are attracted to emerging corn seedlings and begin to cut a small chamber in the stem near or just below the soil level. Eggs are laid in soil in corn fields and developing larvae feed on corn roots but cause little damage. Larvae pupate in late summer and adults emerge and seek overwintering sites. One generation occurs each year.

Management

In south Arkansas avoidance of recently plowed grassy fields including pastures will reduce the attractiveness of the field to adult sugarcane beetles. Damage also is more severe in fields were seed are slow to germinate and where seedling growth is retarded. Thus, delaying planting until soil is warmer will reduce the impact of the sugarcane beetles. Treated seed and soil insecticides applied at planting also are effective tactics.