Integrated pest management (IPM) is a decision-making system that involves the judicious use of diverse pest management tactics after the correct identification of pests. Many producers are already familiar with insect pheromone traps like the ones used in the past for monitoring boll weevils and corn earworms.
Those monitoring programs may have lost momentum in recent years, but insect pheromone-based monitoring technology has continued to improve each year.
Pheromone traps are not magical devices designed to solve all pest problems; they are simply another technology for the scouting “tool-box” that is available.
As you read this article, you may think, “I do not apply insecticides on my peanuts so I do not have to invest in another technology.” But, it may help to think of all the different crops you may be growing within a season on your farm or about crop rotations.
A Haven For Insect Pests
Peanut is a nitrogen-rich, shade-providing crop that serves as a haven for a great diversity of insect pests. Peanut is sort of a “fast-food” for many insect pests that eventually migrate to other crops nearby. Despite the high level of damage peanut plants can withstand, there are still a number of insect pests ranging from thrips on foliage to the lesser cornstalk borer in soil that can destroy peanuts if left unmanaged.
It is always better to know the threat than to assume all is well because it seems so. Insect pheromone traps can be very useful for staying informed regarding insect pest species, activity and migration patterns so that there are no “surprises” during the season.
In order to demonstrate the use of various insect pheromone traps to crop producers and also to comprehensively test the reliability of the latest pheromone lures under Alabama conditions, the Alabama Cooperative Extension System (ACES) has initiated a three-year statewide insect monitoring network that runs east and west for the peanut IPM program and north-south for the vegetable IPM program.
New Extension Initiatives
In 2009, insect outbreak information generated from the pheromone trap network or collected by direct crop scouting was continuously transmitted to producers through a weekly newsletter, the “AU Insect Pest Advisory,” Timely Information factsheets, which are available on the ACES Web site, news releases, the new IPM hotline at 800-446-0375, and, finally, through an extensive insect monitoring project Web site located at www.aces.edu/go/85.
In addition to this Web site, growers and industry personnel had the option to subscribe to blogs at two IPM Web sites, www.aces.edu/go/87 and www.aces.edu/go/88, to receive automatic email alerts, and pest advisories were also posted on AgFax, www.agfax.com, during the peak production season.
In 2010, the Alabama IPM program is initiating the publication of a new statewide, multi-crop publication called the Alabama Ag Alert, which will streamline transfer of information. Alabama Ag Alert is a weekly, electronic publication resulting from teamwork between cropping system/crop protection specialists and Extension educators at Auburn University, Alabama A&M and Tuskegee University.
To receive the Alabama Ag Alert this year, email firstname.lastname@example.org or call 251-331-8416. If you are a peanut producer in Alabama and would like to assist in running a set of traps as part of the IPM network, then also call the previous number to receive a limited number of traps from the peanut entomology program on a test basis.
Trap Network Expands In 2010
This pheromone trap network is a collaborative project for two program priority areas within ACES – the agronomic crops and commercial horticulture. However, the real impact of this project is that it involves producers and Extension personnel working closely together to scout crops and report to project coordinators who will use the information to develop an advanced warning system for other producers who may not be using the monitoring technology.
In 2009, insect traps were installed and serviced in 14 Alabama counties. In 2010, more peanut fields will be surveyed in order to continue the development of site-specific insect forecasting systems with greater collaboration with producers.
Results of the 2009 IPM insect monitoring are compiled herein along with information on new statewide resources available for peanut growers in 2010.
Insect Monitoring Network Findings
In 2009, several types of traps were placed along the field edges of peanut and vegetable farms for season-long insect monitoring.
In five months of trapping (traps were serviced twice each month), the IPM team collected and identified over 8,500 insect specimens from more than 600 samples (trap bottoms) from 14 counties across the state. Each site had about 14 different traps for each insect species.
From May to October, this preliminary pheromone trap network successfully captured 3,586 lesser cornstalk borers; 1,386 fall armyworms; 1,377 beet armyworms; 393 southern armyworms; 589 corn earworms; 342 tobacco budworms; 230 soybean loopers; 125 black cutworms; 266 corn rootworms.
These numbers reflect the abundance of pest species in Alabama and the effectiveness of traps in separating closely related insect species. Not surprisingly, the average trap catch of pest species varied greatly between southern Alabama, the major peanut production area, and the northern or central regions, major vegetable production areas, indicating differences in pest pressures and peak activities. This disparity was less distinct for insect species that reached statewide outbreak levels (e.g., fall armyworm and lesser cornstalk borer).
Insect Pheromone Traps
Insect pheromone traps are reliable predictors of insect activity and should be used in combination with direct crop scouting. A pheromone trap-based smart scouting program can take many years to develop, and producers are encouraged to develop an “IPM action plan” for their farm for effective decision-making. Contact your Extension office to inquire about available IPM programs and to receive free IPM training.
Some benefits of the pheromone-based monitoring systems are as follows:
1. Provides information about early season insect activity. Low insect populations can be difficult to observe, but pheromone traps that use chemical signals in small amounts to attract insects are effective in detecting low populations of insects if deployed in the correct manner. Detecting the early flush of insects is important since future generations can be timed using degree day models for key insect pests.
2. Automatic identification of pest species. Pheromone traps use lures that are species specific, and insects are easy to observe on the sticky trap bottoms. Misidentification of closely related insect species could lead to expensive mistakes because of the different responses to insecticides. Use insecticides judiciously and only after accurately determining the insect pest.
3. As a complement to an insect scouting program. Pheromone traps cannot replace actual crop scouting but producers can time their intense scouting activity with periods of high insect activity as indicated by trap catches. Pheromone traps can easily be a part of your IPM action to develop site-specific pest management strategies. Commonly used insect traps are cost-effective, easy to purchase and service and reusable in most cases. Cost of lures has come down considerably in recent years but depends on insect species to be monitored. Many companies also sell traps in the form of ready-to-use kits, which is a convenient option for producers.
4. To improve decision-making. Over time and with experience, the use of pheromone traps can help improve IPM decision-making. The traps’ sticky surfaces can provide a wealth of information for producers, crop advisors and researchers and can be stored at room temperature.
Some disadvantages of pheromone traps are as follows:
1. Does not indicate actual crop damage. Pheromone traps can complement actual crop scouting but cannot replace it because trap catches simply indicate the activity level of moths and beetles.
2. Effective for monitoring flying insects only. Traps do not estimate the crop injury resulting from feeding by caterpillars on the foliage or by grubs in the soil.
3. IPM training needed. Correct deployment and servicing of traps may require some training because there are specific handling and timing issues for maximum effectiveness of these devices. However, the lures or bait are not considered hazardous.
Low insect numbers in traps do not mean that the insect is inactive. Trap catches can be influenced by weather patterns, trap type and placement method, lure quality and pesticide usage near the sampling area.
Some design issues with the stink bug trap created problems in maintaining those traps, as no stink bugs were caught in the trap even though the insect was abundant inside the crop canopy. Using a sweep net is one of the best ways to estimate stink bug populations in the peanut canopy.
Insect activity trends are considered preliminary because of limited locations and observations and will be combined with the IPM survey this year. Data from multiple years can be used to develop site-specific IPM recommendations based on the observations from trap catches, crop scouting and weather patterns.
Insect pheromone traps also can be used for detecting subtle shifts in pest activity/abundance affected by climate change and other natural phenomena.
Outbreaks In Relation To Trap Catches
If deployed correctly, insect traps integrated with actual crop scouting can provide advanced warning to producers since consistently high trap catches for several weeks indicate overlapping populations and rapid buildup. Ideally, traps should be monitored at least weekly or more often during peak activity.
In 2009, high LCB trap catches correctly indicated hot-spots for larval activity in the soil, which alerted the producers. This year, producers should again be on the lookout for LCB, which can devastate the crop if the weather turns out to be drier than the 2009 season. Such “surprises” can be avoided by using a pheromone-based scouting program for “cryptic” pests like soil insects.
Pheromone traps were also very useful in detecting unusually high activity of fall armyworms in central and northern Alabama about 10 to 15 days ahead of the outbreak. By the time several ACES personnel started getting frantic calls from soybean, vegetable and hay producers, moth numbers in traps across the state were at about 24 to 34 moths per observation period, which is twice the desirable amount.
Use Available Resources To Learn More
Incorrectly identifying closely related insects like corn earworm and tobacco budworm caused major problems for some growers who mistakenly applied the wrong insecticide to many acres resulting in economic losses and rapid population buildup.
Pheromone traps placed a hundred feet apart can accurately separate related insect species like corn earworm and tobacco budworm, beet armyworm and fall armyworm, southern and western corn rootworm species.
Ultimately, the responsibility of detecting and monitoring insect pests falls on individual producers, who are encouraged to use the Alabama IPM program to learn about correct deployment strategies for insect traps and to develop their own “IPM action plan” for sustainable agriculture. PG
Relative abundance and activity period of five major insect pests of peanuts monitored in Alabama using IPM pheromone traps, 2009.
capture of moths
|County with highest
||July - late Aug
||Aug. - Sept.
||Late Aug. - early Sept.
||Late July - early Aug.
|Lesser cornstalk borer,
per trap catch**
|Late July - late Sept.
Traps were serviced twice every month from May to October.
*Denotes the difference in pest pressure between northern and southern counties in Alabama. A low number indicates more uniform distribution across Alabama indicating an outbreak.
**This is an unusually high level of moth activity across the peanut production area. Many LCB outbreaks were reported from counties in southeast and southwest Alabama.