Field Guide     Pest Management     Melanotus Communis

Melanotus Communis

CROPS IMPACTED: sugarcane, potatoes, maize, wheat, sorghum, grasses, small grains

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Family: Elateridae

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About the Melanotus Communis

Reproduction and Life Cycle

The melanotus communis life cycle can take up to 6 years to complete. However, sometimes this wireworm can develop within 3 years, dependent on environmental conditions. The adults that overwinter from the previous year will emerge in the beginning of summer and feed on plant pollen. This pest will then mate; the females lay their eggs soon after. Eggs are placed individually in the ground near roots of host plants, especially grass. The larvae will hatch in July and immediately begin feeding on plant roots. They will mature to their second instar and then overwinter. This wireworm will likely continue to develop through the different larvae stages over the next 5 years. In the sixth year, the fully mature larvae will form cells that are oval in shape and are buried 15 to 30cm underneath the soils surface, where they pupate. This stage takes 18 days. When the adult beetles emerge, they feed on available pollen and then overwinter.

Melanotus Communis Identification and Habitat

Identification

The adult melanotus communis is considered a click beetle, having a smooth, hard body that is approximately 13mm in length and is rust brown to black in colour. The body is narrow and thins down at the end. The eggs are usually spherical or oval shaped with a shiny white appearance, and are a tiny 0.3mm in length. Larvae are light yellow or red-brown and have a brown head that is slightly flattened. They are slim, firm, jointed, and can reach to be about 25mm long. The pupa is white and supple with no coating to protect it; it is oval shaped and is about 13mm long.

Habitat

This pest is common in the southeastern and Midwestern parts of the United States. They are often found in sod that has been recently planted, or in corn fields that have not been tilled. You can also sometimes find them among decomposing logs or beneath tree bark. This pest will eat roots, flowers, and seeds of numerous different plant types. The melanotus communis causes the most significant damage when it reaches seeds that are germinating, or young seedlings. The larvae have been known to eat the entire seed, leaving behind only the outer shell. They can especially injure crop types such as corn if the plant is below 20cm in height; the larvae will feed on the stem and the tap root underground. Symptoms of injury may be rot, jelly secretions from the plant, yellowing of leaves, wilting, and sometimes death. This pest commonly affects crop yield more in growing seasons with wet and cold springs.

Melanotus Communis Management and Control Methods

Cultural Control

To help in the management of this pest, plough to a depth of approximately 9 inches after you have harvested your crops in order to injure pupae and larvae. Also, before you plant in the spring, make sure to disk the soil first. This will injure many of the remaining wireworms in the ground and will also help expose them to natural predators such as birds. Crop rotation is another good practice to reduce this pest’s population. Rotating in plants that are from the legume family can be effective, as these types tend to be more resistant to the damage that this pest causes. Additionally, ensure the soil in your fields has good drainage as the melanotus communis thrives in wet conditions. While these methods can reduce wireworm population, is important to note that having satisfactory control is often dependent on using an integrated management system that includes the use of both cultural and chemical methods.

Chemical Control

For chemical control of wireworms, bifenthrin (Capture), clothianidin (Poncho), thiamethoxam (Cruiser), phorate (Thimet), tefluthrin (Force), and terbufos (Counter) have all been found to have effective results when applied during planting (specific to corn crops). For small grains use imidacloprid (Gaucho), or thiamethoxam (Cruiser) at planting. Be sure to carefully read the label for cautions and proper application. It is extremely important to never spray on days that are windy. After applying insecticides, irrigate sprayed area to increase the insect control. That being said, a large rainfall or irrigation soon after the application can reduce the concentration of insecticides.

Latin / Alternative Melanotus Communis Names

  • - Common wireworm
  • - Corn wireworm

Sources

http://bugguide.net/node/view/468646

http://www.eppo.int/QUARANTINE/insects/Melanotus_communis/DS_Melanotus_communis.pdf

http://ipm.ncsu.edu/AG271/corn_sorghum/melanotus_communis.html