Height and Site Placement of Pheromone Traps for European Corn Borer, Southwestern Corn Borer, & Black Cutworm Armon Keaster (state rep to NCR-148), Michael Boyd, and Darren Hoffman University of Missouri Columbia, MO Pheromone trap placement for surveillance or monitoring for lepidopteran pests of corn is usually at randomly selected sites and at heights of four to six feet. Site ecology is extremely variable if trapping is conducted over a wide area, and trapping results inevitably reflect site variability. Unpublished reports indicate that placement of traps in crops or dense vegetation should be at or slightly below the plant canopy (Mason & Stomdahl 1996). To verify and expand upon this observation, Texas-style (Hartstack et al. 1979) pheromone traps for European corn borer (Ostrinia nubilalis [Hubner]) and bucket traps for southwestern corn borer (Diatraea grandiosella [Dyar]) were placed at trap heights of two, four, six, and eight feet within corn rows and along the borders of a five-acre corn plot in southeastern Missouri (Pemiscot County) in 1996. Peak populations of moths for these two species occur during July and early August. The corn plot pollinated during the last week of June and remained attractive for oviposition over the duration of trapping (mid-July through August). Traps were monitored approximately three times each week, and lures were replaced every two weeks. Southwestern corn borer lures were acquired from Hercon (R), and European corn borer lures were from Scentry (R), (a division of Ecogen). In 1997, traps for European corn borer and southwestern corn borer were placed on individual poles at heights of two, four, six, and eight feet, and also with all four height choices on a single pole. The trap site was an irrigated cornfield of approximately 80 acres, bordered by a grassy strip and a raised roadway. European corn borer was monitored from 21 July through 15 August near Portageville (New Madrid County), Missouri, and southwestern borer was monitored 25 July through 15 August at the same location. Monitoring techniques were similar to 1996, and corn pollinated at approximately the same time. Black cutworm (Agrotis ipsilon [Hufnagel]) was monitored in 1997 from 8 April through 21 May near Columbia (Boone County), Missouri. Traps (Hartstack) were placed on individual poles and on a four-level pole at the same heights as for European corn borer and southwestern corn borer. Traps were located at a site where black cutworm moths have been consistently captured over a period of several years. This site is best described as being at the crest of a hill, in close proximity to a weather station and in an open area approximately 75 feet from vegetation other than grass. Black cutworm lures were from Scentry (TM). Results European corn borer - In 1996, captures were low in July; however, there was a trend for greater numbers of moths to be captured at heights of 4 and 8 feet within the corn plots. In August, moths were captured in the greatest number at a height of 2 feet, both along (grassy) borders and within corn rows. Along the grassy border of the field in 1997, the greatest number of moths were captured at trap heights of 2 and 4 feet on individual poles and also on the 4-level pole. Within the cornfield, greatest captures were at the 6 and 8-feet heights. Southwestern Corn Borer - In 1996, more moths were captured in the grass borders at trap heights of 2 and 4 feet, but the greatest captures within the corn rows were at 8 feet. Moth captures in 1997 were much higher overall than in 1996. Moths tended to prefer the 4-feet trap height along the grass borders in 1997. Fewer moths were captured within the corn rows compared with the grass border, and the greatest capture occurred at the trap height of 8 feet (similar to 1996). The capture at this height is probably because males tend to fly just above the corn tassels in an apparent search for females (R. H. Langille and A. J. Keaster, 1973, Mating Behavior of the Southwestern Corn Borer, Environ. Entomol. 2: 225-226). Black cutworm -Typically, Hartstack traps for black cutworm capture are placed at heights of 3 to 5 feet. These heights were probably chosen and established because of convenience in servicing the traps. However, there are no known publications documenting optimum trap heights. Limited unpublished data (personal communication, W. B. Showers) on a release-recapture study were inconsistent and inconclusive. The greatest capture of black cutworm moths in our 1997 study was at a height of 4 feet (ground level to bottom of trap). Limited data from one or two years cannot be conclusive; however, it is apparent that trap height and placement (within the crop and along borders) does greatly influence the capture of male moths of these three pest species. There is also an indication that the preferred trap height may shift during the summer months. Additional (replicated) studies are needed to define optimum trap heights. [ 1997 Research Index ]
Last updated 1 June, 2007 This page was constructed by Gail Kampmeier at gkamp[at]uiuc.edu Please direct questions of content and prospects of collaborative research to respective scientists. Research reports do not constitute publication and results may be preliminary. They are included here for informational purposes only. You should contact the authors for further information. Any references to commercial products do not constitute endorsement. [ NCR-148 \| Movement & Dispersal Index \| News Index ]

Height and Site Placement of

Pheromone Traps for European Corn Borer,

Southwestern Corn Borer, & Black Cutworm

Armon Keaster (state rep to NCR-148), Michael Boyd, and Darren Hoffman
University of Missouri
Columbia, MO

Pheromone trap placement for surveillance or monitoring for lepidopteran pests of corn is usually at randomly selected sites and at heights of four to six feet. Site ecology is extremely variable if trapping is conducted over a wide area, and trapping results inevitably reflect site variability.

Unpublished reports indicate that placement of traps in crops or dense vegetation should be at or slightly below the plant canopy (Mason & Stomdahl 1996). To verify and expand upon this observation, Texas-style (Hartstack et al. 1979) pheromone traps for European corn borer (Ostrinia nubilalis [Hubner]) and bucket traps for southwestern corn borer (Diatraea grandiosella [Dyar]) were placed at trap heights of two, four, six, and eight feet within corn rows and along the borders of a five-acre corn plot in southeastern Missouri (Pemiscot County) in 1996. Peak populations of moths for these two species occur during July and early August. The corn plot pollinated during the last week of June and remained attractive for oviposition over the duration of trapping (mid-July through August). Traps were monitored approximately three times each week, and lures were replaced every two weeks. Southwestern corn borer lures were acquired from Hercon (R), and European corn borer lures were from Scentry (R), (a division of Ecogen).

In 1997, traps for European corn borer and southwestern corn borer were placed on individual poles at heights of two, four, six, and eight feet, and also with all four height choices on a single pole. The trap site was an irrigated cornfield of approximately 80 acres, bordered by a grassy strip and a raised roadway. European corn borer was monitored from 21 July through 15 August near Portageville (New Madrid County), Missouri, and southwestern borer was monitored 25 July through 15 August at the same location. Monitoring techniques were similar to 1996, and corn pollinated at approximately the same time.

Black cutworm (Agrotis ipsilon [Hufnagel]) was monitored in 1997 from 8 April through 21 May near Columbia (Boone County), Missouri. Traps (Hartstack) were placed on individual poles and on a four-level pole at the same heights as for European corn borer and southwestern corn borer. Traps were located at a site where black cutworm moths have been consistently captured over a period of several years. This site is best described as being at the crest of a hill, in close proximity to a weather station and in an open area approximately 75 feet from vegetation other than grass. Black cutworm lures were from Scentry (TM).

Results

European corn borer - In 1996, captures were low in July; however, there was a trend for greater numbers of moths to be captured at heights of 4 and 8 feet within the corn plots. In August, moths were captured in the greatest number at a height of 2 feet, both along (grassy) borders and within corn rows. Along the grassy border of the field in 1997, the greatest number of moths were captured at trap heights of 2 and 4 feet on individual poles and also on the 4-level pole. Within the cornfield, greatest captures were at the 6 and 8-feet heights.

Southwestern Corn Borer - In 1996, more moths were captured in the grass borders at trap heights of 2 and 4 feet, but the greatest captures within the corn rows were at 8 feet. Moth captures in 1997 were much higher overall than in 1996. Moths tended to prefer the 4-feet trap height along the grass borders in 1997. Fewer moths were captured within the corn rows compared with the grass border, and the greatest capture occurred at the trap height of 8 feet (similar to 1996). The capture at this height is probably because males tend to fly just above the corn tassels in an apparent search for females (R. H. Langille and A. J. Keaster, 1973, Mating Behavior of the Southwestern Corn Borer, Environ. Entomol. 2: 225-226).

Black cutworm -Typically, Hartstack traps for black cutworm capture are placed at heights of 3 to 5 feet. These heights were probably chosen and established because of convenience in servicing the traps. However, there are no known publications documenting optimum trap heights. Limited unpublished data (personal communication, W. B. Showers) on a release-recapture study were inconsistent and inconclusive. The greatest capture of black cutworm moths in our 1997 study was at a height of 4 feet (ground level to bottom of trap).

Limited data from one or two years cannot be conclusive; however, it is apparent that trap height and placement (within the crop and along borders) does greatly influence the capture of male moths of these three pest species. There is also an indication that the preferred trap height may shift during the summer months. Additional (replicated) studies are needed to define optimum trap heights.

[ 1997 Research Index ]