Wireworms (Agriotes spp.)
Identification :
- Wireworms commonly called wireworms are beetles including several species belonging to the genus Agriotesand the family of Elateridae.
- The larvae reach 25mm in length and are orange / brown in color with a narrow, segmented body, biting jaws and 3 pairs of short legs behind the head.
- Its integuments are strongly sclerotized, hence its name of “wireworm”.
- Adult beetles are dark brown or black and are about 2 cm long.
- When alarmed, adults can leap into the air by flexing the joint between the abdomen and thorax, creating a tension like a coil spring that, when released, catapults the insect into the air, emitting a dry noise.
Biology :
- Adult females lay eggs in the soil in the spring.
- The eggs hatch about 1 month later and the young larvae begin to feed on the organic matter in the soil.
- This first instar is white and is 1 to 2 mm long. At this point, very little economic damage is done.
- The larvae continue to grow by molting at the end of each instar and the complete life cycle can take up to 5 years.
- Mature wireworms pupate underground for about 4 weeks, and new adults emerge in July or August and overwinter until the following spring when they lay their eggs.
- At any time, a field can contain all stages of the beetle.
Symptoms :
- Adults of wireworms are not harmful.
- It is the larva, which is very polyphagous, which causes damage by attacking beets during the establishment phase, during which it cuts the rootlets.
- This damage occurs mainly from emergence to the 4-6 leaf stage and can be extensive, including destruction of seedlings.
Control :
- Chemical control using VYDATE 10G at a dose of 20 Kg / ha.
