Posted 16 May 2010. PMN Crop News.
Keep an Eye on Pest Pressures on Field Crops
Source: The Ohio State University Press Release. www.oardc.ohio-state.edu
Wooster, Ohio (May 5, 2010)--This warm spring weather may be suitable for planting, but it’s also ideal for pest development.
“This is the time when we like to remind growers to get out in their fields and scout for insects and other pests,” said Ron Hammond, an Ohio State University Extension entomologist. “Plants can take a lot when it comes to insect defoliation in the early stages of their development, but if insect populations get bad enough, they can stunt plant growth and affect grain fill, so now is the time growers need to take steps to protect their crop.”
Early spring pests that could impact crops include:
• True armyworms – True armyworm larvae can do the most damage to wheat during the crop’s flag leaf emergence stage, which is now occurring across Ohio. The pest can also attack corn that is planted adjacent to wheat or when planted into a rye cover crop. Reports from neighboring states indicate the true armyworm moth is now taking flight, but the good news is numbers appear low at the present time.
• Cereal leaf beetle – The cereal leaf beetle has become more common over the past few years and can do economic damage to cereal grain crops such as wheat and oats. “The cereal leaf beetle will attack wheat in the flag leaf emergence stage long before the true armyworm, so growers should keep a close eye out,” said Hammond.
• Alfalfa weevil – As Ohio’s alfalfa crop approaches its first cutting, growers should keep an eye out for alfalfa weevil damage. “The concern will then turn from damage to re-growth,” said Hammond.
• Slugs – As corn and soybeans begin emerging, slugs will be waiting to feed on the young plants. “The areas with prior slug problems that haven’t been planted yet will be the biggest concern,” said Hammond. “The goal is to try and plant early enough so the crops have a chance to outgrow slug damage.”
• Black cutworm – Like true armyworms, black cutworm moths are also now in flight across the Midwest. Larvae, which hatch out later this month, enjoy feeding on and cutting young corn plants. “The biggest concern is with late-planted corn because of the smaller size of the plants and the cutworms’ ability to cut more of them,” said Hammond.
• Bean leaf beetle – Soybean growers could see a lot of early season feeding from bean leaf beetle. “As we get into May and the plants emerge, we could see a lot of insect activity on early growth,” said Hammond.
Hammond said that scouting is one of the most important management practices of crop production.
“Not all insects are controlled with transgenic varieties, and while seed treatments may do an adequate job with some pests, they don’t work with others, such as the black cutworm,” said Hammond.
For more information about agronomic crop insects and pests, log on to entomology.osu.edu/ag.