SEEDCORN BEETLE: Stenolophus lecontei, and SLENDER SEEDCORN BEETLE: Clivina impressifrons, Carabidae

ADULT: Seedcorn beetle adults are dark brown below and yellowish- to reddish-brown above.  Their wing covers (elytra) are black with lighter colored bands around margins. Slender seedcorn beetle adults are chestnut-brown with flattened front legs. Both beetles are in the range of 1/4 to 5/16 in. long.  Neigher have mandibles with a hardened, raised area (including teeth or ridges) near base.

EGG: Tiny, white, oval-shaped eggs are deposited in tunnels in the soil.  Larvae emerge in 3 to 12 d at 72 degrees F.

LARVA: They are pale yellow to light brown with three pairs of short true legs. The head and top of first thoracic segment are darker than the abdomen. Larvae reach 9/16 in. long and complete development in 18 to 56 d at 72 degrees F.

PUPA: Newly molted pupae are pale white, but quickly turn dark brown or black within cells in the soil.  Adults emerge in 7 to 13 d at 72 degrees F.

GENERATION TIME: 28 to 81 d at 72 degrees F.

DAMAGE: Larvae and adults mostly eat insects, live or dead, but will attack seeds of germinated but not emerged seedlings of several grains, vegetables and weeds in soil. They are found more commonly on heavy, moist soil where seed germination may be delayed. Larvae and adults both travel through soil and across the soil surface to get to seeds and seedlings.  Their attack results in an uneven or poor stand.  Damage on the high organic soils is also associated with planting to previously fallowed, uncultivated fields.  Other species in this family share similar habits and damage germinating seeds and pre-emerged seedlings when planted to newly cleared or other lands that have been out of production.

CONTROL: Adult populations can be monitored with pitfall and black light traps.  Pesticides are available for pre- and at-plant broadcast, banded and in-furrow applications.  To protect corn planted to weedy fallowed fields on high organic soils, combinations of pesticides mixed with the soil and placed in-furrow may be necessary to control these beetles. Formulations, rates, and pre-harvest intervals of insecticides labeled for seedcorn beetle control in Florida are listed below for sweet corn (Table 1) and field corn (Table 2).