Sunflower XIV

Wireworms

Frank B. Peairs

 

Wireworm

Identification (and life cycle/seasonal history)

Wireworms are the larval stage of a family of beetles commonly called "click beetles." There are several species of wireworm whose life cycle may require one or more years per generation.  The insects usually overwinter in the adult stage.  Adults are brownish or even blackish in color, elongate and tapering toward each end but more so toward the rear.  The earliest stages of larvae are very small and white, later stages have a characteristic hard-shell appearance and a yellow-brown color.  Mature larvae range from ? to one inch in length, depending on the species.

Females deposit eggs in the soil among grass roots.  When the eggs hatch the larvae feed on the roots of a variety of plants, including sunflower.  The larvae mature in from two to five years.  Fully developed larvae form pupation chambers in the soil and pupate.  Adults emerge from the pupae and remain in the soil until the following spring.

Plant Response and Damage

Wireworms are found around the roots of sunflower plants in the spring. Young plants killed in an irregular areas of the field is characteristic damage.  Wireworm problems are most common sunflower planted in wheat stubble, because adults are attracted to grasses for egg laying.

Management Approaches

Biological Control

No applied biological control practices exist for control of wireworms.

Cultural Control

Clean summer fallow, fall tillage to crush pupae, and flooding to kill larvae are some examples of cultural practices. Generally, healthy, well-fertilized plants tend to outgrow wireworm damage.

Chemical Control

For wireworms use a Cruiser or lindane-based seed treatment.

 

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: Sunflower, Insects, Wireworms

 

Date: 5/17/2007