Girdle beetle, also known as grape colaspis, is a pest that can cause significant damage to soybean crops. Their larvae feed on the roots of the plant, which can lead to stunted growth, yellowing of leaves, and overall reduced yield. To prevent damage from girdle beetles, it is essential to implement effective control measures.
1. Crop Rotation
One of the most effective ways to control girdle beetles is by rotating soybean crops with non-host crops such as wheat, corn, or cotton. Rotation limits the concentration of pests on one crop by reducing the availability of food. Several studies have shown that crop rotation can significantly reduce the population of girdle beetles.
2. Tillage
Deep plowing can help break the life cycle of the girdle beetle by exposing the larvae to predators and other environmental factors. Deep tillage can also destroy overwintering sites and eliminate soybean residue from the field. Tillage will also help to bury weed hosts and limit beneficial insect populations.
3. Use of Insecticides
Insecticides are among the most common means of controlling girdle beetles. They can be applied as either a foliar spray or a soil treatment. For best results, apply the insecticide during early spring or at the start of planting when the soil temperature reaches 60°F or higher. Commonly used insecticides include lambda-cyhalothrin, acephate, and thiamethoxam.
4. Plant Resistant Varieties
Planting soybean varieties that are resistant to girdle beetle damage can be a valuable control measure. These varieties typically have stronger root systems that are more resistant to the feeding damage caused by girdle beetles. Some examples of resistant varieties include Asgrow AG5232, Pioneer 95Y70, and Pioneer 94Y11.
5. Timing of Planting
Planting soybean crops early can also help reduce girdle beetle damage. Early planting allows soybeans to develop a strong root system before girdle beetles become active. Additionally, planting early can help soybeans tolerate damage caused by girdle beetles and still produce high yields.
In conclusion, controlling girdle beetles in soybean crops requires a combination of measures such as crop rotation, tillage, use of insecticides, planting resistant varieties, and timing of planting. Farmers that adopt integrated pest management strategies are more likely to have successful results in controlling pests such as girdle beetles.