1994 Turf Insect Monitoring

March 16, 2005

Summary: An insect monitoring study was initiated to provide the basis for a turf insect integrated pest management (IPM) program. Weekly black light trap counts of adult insect pests of turf were collected from ten Southern California golf courses from March 7 through October 12, 1994. Key results from the study’s first year include:

• Black turfgrass ataenius (BTA) was the most damaging and most difficult to control insect detected, particularly on cool season turf (bentgrass, rye, bluegrass and mixtures). Damage caused by BTA was a combination of direct feeding by grubs, and damage caused by birds searching for grubs. At least 3 generations of BTA were observed from late June to early October. This is in contrast to the 1 - 2 generations recorded for BTA in the Eastern U.S., where it has been most widely studied.
• Black cutworms and common armyworms were an almost constant presence at all courses from April through September. Larvae (caterpillars or worms) of these insects caused some damage at several courses, but populations were easily controlled through insecticide applications. Damage caused by these pests was a combination of direct feeding by insect larvae, and damage caused by birds searching for larvae.
• Bird damage was observed at all courses on greens and tees, especially in late July and early August. However, cutworm and armyworm larvae were sometimes difficult to find despite the bird damage. One possible explanation is that birds were searching for BTA grubs which were prevalent during this time period, rather than for cutworms and armyworms.  Because BTA grubs are rarely seen on turf (they are very small and feed in the thatch/soil interface), the damage they cause may erroneously be attributed to cutworms
• The population models currently available for prediction of BTA and black cutworm development were designed for temperate climates where average air temperatures frequently dip below 32 F . For this reason these models were not applicable for Southern California where average air temperatures are rarely below 50 F.
• Attempts to monitor armyworm and cutworm larval populations via the soil drench method did not provide useful information for the purposes of timing insecticide applications. Black light trap counts of adults and monitoring for insect and/or bird damage were more reliable indicators of the presence of these pests.
• Other pest insects including sod webworms, variegated cutworms, masked chafers and May/June beetles were detected at all participating courses, but caused no significant damage to turf in 1994.

Printable version of full report

Principal Investigators: Wendy Gelernter, Ph.D. Larry Stowell, Ph.D.

Cooperators and Sponsors: Brian Darrock, Fairbanks Ranch Country Club Raymond Davies, Virginia Country Club Bill Gallegos, Los Coyotes Country Club Mike Hathaway, Los Angeles Country Club Eric Lover, Dove Canyon Country Club John Martinez, Arrowhead Country Club Brian Massey, Target Specialty Products Ben McBrien, Sea Cliff Country Club Mark Phillips, Leisure World, Laguna Hills Greg Swanson, San Luis Rey Downs Reed Yenny, Mesa Verde Country Club