Sugarbeets XX-20

White Grubs

Gary L. Hein

White grub larva

White grub problems in sugarbeet are uncommon. Treatment for this insect would not likely be economic unless planting into a high risk situation (i.e. following sod or grass).

Identification (life cycle and seasonal history)

White grubs are C-shaped insects ranging in length from 1/2 to 1 1/2 inches. These larvae live in soil for extended periods of one to three years. The adults are active in early summer when they emerge from the soil, mate and lay their eggs in grass or pasture areas.

Plant Damage and Response

White grub problems are mostly limited to crops, especially row-crops, planted following sod or other grasses. However, they may also build up in cropland where grass weed problems have been severe. They feed on the sugarbeet root and can cause problems early in the year when plant damage can lead to stand loss. Damaged plants at this time will wilt and die. Also, late season feeding can result in beets that have had their surface severely pitted by grub feeding.

Management Approaches

Sugarbeet and other row crops should not be grown following sod. If grub problems are expected, a soil applied insecticide may provide some degree of control; however, severe white grub infestations are difficult to control.

Product List for White Grubs:

Insecticide	Product per Acre	Preharvest Interval , remarks
Counter 15G^R, CR^R	15G: 4.0-8.0 oz/1000 row ft CR: 3.0-6.0 oz/1000 row ft	Applied banded at planting or post emergence; REI 72; PHI 110 days.
Mustang MAX^R Section 24c label in NE, CO, WY, MT	4.0 oz/A	Apply in-furrow or 3-4 inch T-band at planting. REI 12 hours.
^RRestricted use pesticide.
"The information herein is supplied with the understanding that no discrimination is intended and that listing of commercial products, necessary to this guide, implies no endorsement by the authors or the Extension Services of Nebraska, Colorado, Wyoming or Montana. Criticism of products or equipment not listed is neither implied nor intended. Due to constantly changing labels, laws and regulations, the Extension Services can assume no liability for the suggested use of chemicals contained herein. Pesticides must be applied legally complying with all label directions and precautions on the pesticide container and any supplemental labeling and rules of state and federal pesticide regulatory agencies.  State rules and regulations and special pesticide use allowances may vary from state to state: contact your State Department of Agriculture for the rules, regulations and allowances applicable in your state and locality."

Categories: Insects, Sugarbeets, White Grubs

Date: 04/19/2006