A changing climate is set to increase the number and virility of corn pests, which could have a devastating effect on maize production in th...
Case Studies
Populations of insects that feed on corn and other crops in the United Kingdom may flourish and expand to new territory as global climate change brings warmer summers and milder winters in the decades ahead, according to a new study.
More frequent or more severe pest infestations may cut crop yields and drive up the price of corn, used for food and animal feed and to produce renewable fuels.
Projections showed all of the species studied spreading into agricultural areas where they currently are not endemic. The greatest potential range expansion was seen with the Western corn rotworm, which is known to infest other high-value crops such as sweet corn and tomatoes. Warming could allow populations to survive the winter in the south of the country, the key region for corn and forage maize production.
Researchers used climate model simulations that suggest winters will be milder more often later in the 21st century while summer growing seasons will be longer and warmer more often than they are now. They compared the climate models to the temperature survival thresholds of four common corn pests found in the United Kingdom.
Essentially, both the number of days warm enough for the pests to grow and the number of days cold enough to kill the pests were examined, which allowed the researchers to see what could happen in projected future climates.
More frequent insect pressure means farmers will need to spend more on pesticides or high-priced biotech seeds that help control pests or risk yield losses, researchers said. More frequent pest problems can also result in more variable yields, which can drive up the cost of crop insurance or disaster relief for farmers. Losses due to insect pests, including the resources required to control them, is the biggest cost for corn production.
The European Corn Borer, Ostrinia nubilalis (Hubner), is an introduced insect species, a moth larva, and the most damaging insect pest of maize as it feeds on sweet, grain and silage corn. It significantly affects production of field corn, popcorn, seed corn, and sweet corn, as well as other crops (including sorghum, cotton, and many vegetables).
This insect may cause several types of damage. Where this pest is active, the development of borers in corn stalks:
This devastating crop pest can reduce maize yield by as much as 15 percent, in years of high infestation. In addition, the damage to maize kernels leads to higher levels of fungal infestation and production of mycotoxins.
Western corn rootworm, Diabrotica virgifera virgifera LeConte is a type of beetle, which has been a major economic pest of maize in the Americas for many years. However, since the early 1990's it has become an increasing threat to crops in Europe and is expected to spread to all maize growing areas of the continent.
Most of the damage in corn is caused by larval feeding. Newly hatched rootworms locate corn roots in the soil and initially begin feeding on the fine root hairs and burrow into root tips of the corn plant. As larvae grow larger, they feed on and tunnel into primary roots.