Where does corn rootworm come from?
Western and northern corn rootworm have only one generation per year. Eggs of both species are deposited in the soil by female beetles from mid-summer until autumn. The eggs overwinter and begin hatching from late May to early June in most areas of the Midwest. The newly hatched larvae seek out and feed on corn roots.
Where do western corn rootworms live?
Both species of rootworm prefer to deposit their eggs in cornfields. Females deposit most eggs near the base of corn plants, within the top six inches of the soil surface. (Western corn rootworm females may deposit their eggs throughout the field.)
How do you identify western corn rootworms?
Adult WCR are typically slightly larger than NCR and are yellow in color with three dark stripes running lengthwise on their hardened forewings. These stripes can vary from three distinct lines to one large stripe covering most of the forewing. Western corn rootworm (the three on the right are males).
Where do corn rootworms overwinter?
These insects overwinter as eggs in the soil at depths that range from 3-6 inches. Previous research indicates that the two species of corn rootworms differ on their ability to survive cold temperatures.
How many eggs does a rootworm lay?
A female may lay an average of 500 eggs over several weeks in clutches of about 80 eggs. Most eggs are laid in the upper 6 inches of soil during late summer. During dry years, females will enter cracks in the soil to lay eggs as deep as 10 to 12 inches. Eggs remain dormant until the following spring.
What is Bt corn?
Bt-corn is a type of genetically modified organism, termed GMO. A GMO is a plant or animal that has been genetically modified through the addition of a small amount of genetic material from other organisms through molecular techniques.
How do you scout for corn rootworms?
To check for the presence of larvae in a field, dig a 7-inch cube of soil centered on the corn plant. Sample a minimum of two plants at each of five sites in a field. Carefully search through the soil and plant roots for larvae.
What does corn rootworm eat?
Northern corn rootworm adults feed on reproductive tissues of the corn plant, but rarely feed on corn leaves. “Northern” adults are more likely than “western” adults to abandon corn and seek pollen or flowers of other plants as corn matures.
How do you control corn rootworms?
Five Steps to Controlling Corn Rootworm
- Rotate crops. Plant soybeans when possible to break up corn-on-corn rotations.
- Choose trait packages. Corn farmers should choose hybrids that feature two traits for maximum corn rootworm control.
- Use full insecticide rates at planting.
- Be proactive.
- Control volunteer corn.
What is the life cycle of the corn rootworm?
The western corn rootworm (WCR), northern corn rootworm (NCR), and southern corn rootworm (SCR) all have a similar lifecycle, which includes four stages: the egg, larva, pupa, and adult. The NCR and WCR both overwinter as eggs in the soil, but the SCR overwinters as a beetle.
What is HT corn?
Herbicide-tolerant (HT) crops, which tolerate specific broad-spectrum herbicides (such as glyphosate, glufosinate, and dicamba), provide farmers with a broad variety of options for effective weed control.
Who approves GM crops in India?
The top biotech regulator in India is Genetic Engineering Appraisal Committee (GEAC). The committee functions as a statutory body under the Environment Protection Act 1986 of the Ministry of Environment & Forests (MoEF). It was earlier known as Genetic Engineering Approval Committee.
Where can I find information related to the western corn rootworm?
Wikispecies has information related to Western corn rootworm. The Western corn rootworm, Diabrotica virgifera virgifera, is one of the most devastating corn rootworm species in North America, especially in the midwestern corn-growing areas such as Iowa.
What is the economic impact of corn rootworms?
The United States Department of Agriculture estimates that corn rootworms cause $1 billion in lost revenue each year, including $800 million in yield loss and $200 million in cost of treatment for corn growers. There are many similarities in the life cycles of the northern and western corn rootworm.
Is egg development temperature-dependent in the western corn rootworm?
A temperature-dependent model of egg development of the western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae). Canadian Entomologist, 123(6):1183-1197
What is the life cycle of a corn rootworm?
There are many similarities in the life cycles of the northern and western corn rootworm. Both overwinter in the egg stage in the soil. Eggs, which are deposited in the soil during the summer, are American football-shaped, white, and less than 0.004 inches (0.10 mm) long. Larvae hatch in late May or early June and begin to feed on corn roots.