Mole cricket management using a soil fumigant Long used in agriculture, 1,3-0 is being tested for controlling mole crickets in turf. J. Bryan Unruh, Ph.D., and Darin W. Lickfeldt, Ph.D. Mole crickets have long been trou- roots, organic material and other small blesome pests in turf-covered venues, organisms, including insects. particularly in the southeastern United During warm weather, most mole States. Imported from South America in cricket feeding occurs at night after the early 1900s, mole crickets damage rain showers or irrigation events. turfgrass in several ways. They tunnel During the day mole crickets stay in through the soil near the surface, loos- their permanent burrows and may ening the soil and leaving the grass remain there for long periods when the uprooted. As the soil dries, the roots weather is unfavorable. Adult mole desiccate and turf death ensues. Mole crickets are strongly attracted to lights crickets also cause direct injury as they during their spring flights, and there feed on grass roots, causing thinning of are reports of mole cricket sightings on the turf and inevitably leading to bare well-lit, offshore oil rigs. More Info: www.gcsaa.org soil. Indirect injury also occurs when predatory animals such as armadillos Mole cricket control • Mole crickets kill turf by and opossums seek their nightly meal of Control of mole crickets has largely feeding on roots and by these soil-borne insects. been accomplished with synthetic uprooting grass through Mole crickets are extremely prolific. insecticides (5,6) and, more recently, tunneling. Each spring, overwintered adults with biological control agents such as • Long used in agriculture, emerge, fly around and mate and then the entomopathogenic nematode the pesticide I,3-dichloro- deposit eggs in chambers hollowed out Steinernema scapterisci and the propene has recently been in the soil. Most chambers are found in Brazilian red-eyed fly, Ormia depleta tested on turf under an the upper 6 inches of soil, but cool tem- (4). Recently, however, several Experimental Use Permit. peratures and/or dry soil result in researchers have been evaluating 1,3- • In comparative tests with chamber construction at greater depths. dichloropropene, a soil fumigant, for its products used to control After hatch, the young nymphs escape usefulness in controlling mole crickets. mole crickets, I,3-D's per- from the egg chamber and burrow to l,3-dichloropropene (l,3-D) was formance was similar to the soil surface in search of food. These developed in 1943 and was the first that of the other products. young mole crickets begin feeding on effective and inexpensive nematicide February 2002 • GeM 57 for general field use (2). In turf, 1,3-D has been very effective when injected was tested for nematode control in into the soil under a turfgrass sod for bermudagrass turf in 1953 (1). Over nematode management. However, to the years, researchers and practitioners substantiate the claims of mole cricket have noted that 1,3-D (sold under the and ancillary insect control, extensive agricultural trade name, Telone II) pro- testing has been conducted since 1999. vided not only exceptional control of nematodes, but also control of some Research projects soil-borne insects (3). Therefore, Dow Trials have been conducted each AgroSciences has been in the process of summer since 1999 to determine the developing turf use labels for 1,3-D. efficacy of 1,3-D for insect control in Tested under an experimental use per- Florida. In all the studies, three or four mit, 1,3-D (turf trade name, Curfew) replications of relatively large plots (~1,500 square feet) were used, and the applications were made using a tractor- driven coulter/shank injection rig. 1,3- D was injected to a depth of at least 6 inches and the coulters/ shanks were spaced 12 inches apart. Tests have been conducted on golf course Tifway berm udagrass fairways and driving ranges maintained at 0.5 inch. Because use of 1,3-D requires a 24-hour re- entry interval and a lOa-foot setback from an occupied structure (such as a school, hospital, business or residence), care was given to assure compliance with these regulations. Nitrogen rate varies from location to location. Sandestin Golf and Beach Resort - 1999 Methods. A trial was conducted at the Sandestin Golf and Beach Resort in Destin, Fla., in the Florida panhandle, in summer 1999 to determine the level of turf injury that 1,3-D might cause versus the level of turf injury caused by the application equipment. 1,3-D (9.4 SL formulation: 94 percent 1,3- dichloropropene) was applied on July 7, at 5 gallons per acre, using the equip- ment described above. The fumigant was injected at 4, 6 or 8 inches below the turf surface. To assess the turf injury from the equipment alone, plots were o treated in a similar manner, without >- 'g'" applying the fumigant. An untreated 8 control was also included. o o .r; 0.. Results. Regardless of rating date, no significant differences were noted Proper irrigation and fertilization promote healing of coulter injury incurred during soil injection of 1,3-0 fumigant. Coulter injury is shown at three among application depths or between days after treatment (top); the healed turf is shown at two weeks after treat- plots treated with 1,3-D or equipment ment (bottom). only (data not shown). 58 GeM • February 2002 Bottom line. A minimal level of injury (necrosis or browning of the turf) occurred where the coulter cut the • 1,3-0 5 gallons/acre • Chlorpyrifos (2% a.i.) turf and the fumigant was injected . • 1,3-0 10 gallons/acre • Untreated However, after two weeks, the brown 100 a a "cut lines" were hardly noticeable and were typically greener. 80 Ft. Walton Beach Golf Club - 2000 Methods. A trial was conducted at the Ft. Walton Beach (Fla.) Golf Club in e 60 +-' the Florida panhandle in summer 2000 c: o to determine whether 1,3-D would pro- u vide effective control of mole crickets ~ 40 when soil-injected on a golf course dri- ving range. Using the equipment 20 described above, 1,3-D was applied at 5 and 10 gallons per acre on June 22. As a comparative treatment, chlorpyrifos o (Dursban Coated Granules, 2 percent 20 39 69 a.i.) was applied at 200 pounds/acre. Days after treatment Results. At 20 and 39 days after treat- ment (DAT), 1,3-D at both 5 and 10 gal- Bars labeled with the some letter indicate values that are not significantly different from one another. The trial was lons/acre provided mole cricket control conducted at Fort Walton Beach (Fla.) GC by J. Bryon Unruh, University of Florida, Joy. that was not significantly different from the control provided by chlorpyrifos. By 69 DAT,however, l,3-D control of mole crickets diminished to 57 percent for the 5-gallon rate and 70 percent for the 10- Effect of 1,3-0 and chlorpyrifos on turf quality gallon rate, while chlorpyrifos contin- ued to provide 85 percent control. • 1,3-0 5 gallons/acre • Chlorpyrifos (2% a.i.) • 1,3-0 10 gallons/acre • Untreated Some surprising observations were 8 a noted with turfgrass quality, however. At 39 DAT, both rates of l,3-D had 7 unacceptable turf quality, attributed largely to burn associated with the 6 fumigant. By 69 DAT, turf quality in plots treated at the 5-gallon rate did not 5 differ from turf quality in the untreated .£ ~ 4 plots. Turf quality in plots treated at the o la-gallon rate was significantly below 3 that of the untreated plots. The treated area was a driving range, and the turf 2 had received inadequate irrigation and only minimal fertilizer application so that it did not have the needed o resources to recover from the applica- 39 69 tion injury. Days after treatment Bottom line. Results from this study showed that chloropyrifos and 1,3-D Bars labeled with the some leiter indicate values that are not significantly different from one another. The trial can control tawny mole crickets effec- was conducted at Fort Walton Beach (Fla.) GC by J. Bryon Unruh, University of Florida, Joy. tively. Results from this trial also revealed the importance of optimal February 2002 • GeM 59 pre- and post-application cultural prac- tices. Irrigation and nutrient manage- ment must be adequate to offset the III 1,3-0 5 gallons/acre • Fipronil • 1,3-0 10 gallons/acre • Untreated limited injury that can be observed a when using 1,3-D. 100 Shoal River Country Club - 2001 Methods. A trial was conducted at 80 Shoal River Country Club in Crestview, Fla., in summer 2001 to determine 60 whether soil-injected 1,3-D would pro- e..... c: vide effective control of mole crickets 0 u on a golf course fairway. Using the ::R 0 40 equipment described above, 1,3-D was applied at 5 and 10 gallons per acre on May 29. As a comparative treatment, 20 fipronil (Chipco Choice, 0.0125 G) was surface broadcast at 12.5 pounds/acre. Results. On all three rating dates (31, 0 31 51 79 51 and 79 DAT), there were no signifi- cant differences in mole cricket control Days after treatment among all the treatments. In this study mole cricket control with 1,3-D was Bars labeled with the some letter indicate values that are not significantly different from one another. The trial was conducted at Shoal River CC, Crestview, Fla., by J. Bryon Unruh, University of Florida, Joy. more variable than that achieved with fipronil, an industry standard.