What is my worm pressure?

One of the moths we trap is Helicoverpa zea which is known as soybean podworm, cotton bollworm, and corn earworm.

Planting season is rapidly approaching and it is never too early to think about potential problems that are lurking. Last season, many producers were caught off guard by a heavy worm pressure. Unfortunately, we don’t know what kind of pressure we will have in 2011 but the University of Missouri’s Plant Protection Programs offers a way that growers can have a better idea of what the worm pressure may be like in their area.

It is difficult to monitor worms on a large scale since they are confined to plants and are not very mobile, but adults (moths) are mobile and can easily be monitored using pheromone traps.  Female moths produce pheromones which are similar to a heavenly perfume that drives the male moths crazy. Each species of moth produces its own special perfume that is attractive only to the males of the same species. Scientists have developed man-made pheromones that will draw in male moths from nearby areas and we use them to estimate what the moth populations are like in a given area.  Pheromone trapping does not replace scouting your crops but it is a useful tool for pest monitoring. For instance, a trap may be catching very few moths and then spike to hundreds of moths captured in a single night. You wouldn’t want to treat based on the increase in numbers, but you would want to check your crop more frequently. For example, insects have preferences for food, just like people do.  If the crop is not at the right stage for the insect, the crop may escape damage because the insects choose to feed on something other than the crop.

In Missouri, we have nearly 30 trappers who are monitoring insect pests using more than 130 traps across the state. Not all pests have man-made pheromones for monitoring purposes, but we have pheromone traps for 11 common insect pests that damage crops grown in Missouri. Black cutworm, true armyworm, Japanese beetle, European corn borer, corn earworm and fall armyworm are trapped throughout the state and Southwestern corn borer, tobacco budworm, beet armyworm, and soybean looper are trapped in southern and southeast Missouri.  You can access the trap captures by visiting MU’s IPM Pest Monitoring Network (http://ppp.missouri.edu/pestmonitoring/index.htm).

With time being so precious, you may not have time to check capture numbers regularly. To remedy this, you can sign up for pest alerts on MU’s IMP Pest Monitoring Network webpage (http://ppp.missouri.edu/pestmonitoring/subscribe.htm). When pest numbers reach a set point, alerts are sent out electronically. All you have to do is go to the above listed website, provide all the required information, select the insects for which you are interested in receiving alerts and click submit. Also, we are developing additional materials for each insect to provide information on pest identification, scouting methods, thresholds, damage caused by the pest and other useful  tidbits.

-Kelly Tindall

Categories: Insects, Monitoring

Tags: , ,

1 reply


  1. Information you need: Moth Monitoring | bootheelagpestmanagement

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