A PRACTICAL RESEARCH DIGEST FOR TURF MANAGERS Volume 10, Issue 6 • June 2001 ¡TURFGRASS PEST CONTROL IN THIS ISSUE • The changing of the The Changing of the guard in white grub Guard in White Grub control insecticides 1 Organophosphate/ Control Insecticides carbamate update New product information By Kevin Mathias Natural control influence of insecticides combination of federal regulatory rulings and economic decisions by insecticide Multiple targeting manufacturers has dramatically changed the landscape of white grub insecticides A and control strategies. At the beginning of the 1990's white grub control insecti- • Site analysis for golf cides consisted mainly of organophosphate and carbamate based chemistries with only a course development 7 few biorational products available (Table 1). As a group, the organophosphate and car- Climate bamate insecticides, have a relatively short residual activity and are highly efficacious when used in curative control programs. Topography Optimum results are attained if the products are applied in mid to late August or into September, as white grub damage is first noticed and Drainage patterns when the grubs are young and relatively small. Optimum results are Water availability As we enter the new millennium many of the cura- attained if the tive control products have been replaced by a group of Soils and geology products are applied new insecticides. These insecticides, Merit and Mach 2, offer greater applicator safety, have less adverse effect Environmental issues in mid to late August on the environment, provide a longer window of appli- Wetlands or into September, as cation due to their extended soil residual activities, have minimal impact on beneficial predators, and pro- Water quality white grub damage vide excellent control (+90%) of white grubs. is first noticed and Merit and Mach 2 affect the early instar stages of • Letters to the editor. 14 white grubs and are much more effective in preventa- • From the editor. 15 when the grubs are tive than in curative control programs. A review of field young and relatively evaluations for white grub control reported in Arthro- We'll miss you, Mike pod Management Tests from 1998 to 1999 demon- small strated that applications of Mach 2 or Merit applied within the early June to early August time period pro- vided excellent control (+90%), however, if these insecticide were applied from late August through September the average level of con- trol dropped to 80%. A recent survey conducted at the 2001 Maryland Turfgrass Conference illustrates how turfgrass managers have incorporated these new insecticides into their insect control pro- grams (Figure 1). Merit was used by 60% of the respondents, followed by Dylox at 28%, and then Mach 2 at 19% for white grub control. TURFGRASS TRENDS Executive Editor Sue Gibson 440/891-2729; 440/891-2675 (fax) Dylox, an organophosphate, was product is Meridian (thiomethoxam) and sgibson@advanstar. com applied as a curative control for spot treat- white grub evaluation studies have shown Managing Editor ment to sites that had not been treated excellent efficacy when applied preventa- Curt Hurler with Merit or Mach 2. tively. Field evaluations of Meridian 440/238-4556; 440/238-4116 curt@curtharler. com demonstrated excellent control (97%) On Line Editor Organophosphate I when applied within the June to early Lynne Brakeman carbamate update August period (Table 2). However, if Senior Science Editor The ongoing review process mandated by applied in a curative manner, late August Dr. Karl Danneberger the Food Quality and Protection Act of through September, control levels Group Editor 1996 and under the direction of the Envi- dropped to 80% for Japanese beetle, Vern Henry ronmental Protection Agency (EPA) has masked chafers, and oriental beetles. Production Manager continued to affect product choices for European chafer control showed an Rene' Fall 218/723-9352; 218/723-9223 (fax) turf grass insect control. Dursban's (chlor- even greater drop when used as a preven- rfall@advanstar. com pyrifos) new turfgrass labeling removes the tative, 82% control, to 22% control when Senior Graphic designer application of this product to residential applied in a curative manner (Table 2). Jeff Landis sites and restricts applications only to golf The proposed labeling for Meridian rec- 440/891-2702; 440/891-2675 (fax) jlandis@advanstar. com course and industrial sites. It also limits ommends an application window for maximum application rates of 1 lb. white grubs 45 days before adult flight Circulation Manager Cheryl Beeman A.I./acre per season. activity to second instar development with 218/723-9271 Though never a stellar white grub con- optimal timing at peak egg hatch. Addi- Group Publisher trol product due to its tendency to bind to tional insects for which Meridian will be John D. Payne 440/891-2786; 440/891-2675 (fax) organic matter, Dursban was effective at jpayne@advanstar. com the 2 lb. A.I./acre rate for adult control of the black turfgrass ataenius beetle. When Corporate & Editorial Office What we must do as 7500 Old Oak Blvd. applied in early spring prior to egg laying, Cleveland, OH 44130-3369 Dursban will control the adults thus pre- turfgrass managers and Mew Subscriptions venting or reducing egg laying. 888/527-7008 researchers is to continue to Various pyrethroid insecticides such as Abstracts: 800/466-8443 Talstar and DeltaGard are now replacing improve our abilities to Reprint: 440/891-2744 Dursban for this use. Permission: 440/891-2742 predict the likelihood of Single copy or back issues: Turcam (bendiocarb), a carbamate insec- Subscription/Customer Service ticide manufactured by Aventis, will no white grub damage. 888/527-7008; (fax) 218/723-9437 Web site address: longer be produced for turfgrass insect con- www. landscapemanagement. net trol in 2001. This was a voluntary decision by the manufacturer based on economic labeled for include billbug larvae and fire considerations. Current supplies can be sold ant control and suppression of chinch bugs until the existing inventory is depleted. and mole crickets. ÄDVANbTAR Diazinon is the most recent product to C OMMUNICATiONS see future regulations affect its use in the Natural control influence Chairman and market place. It will lose its labeling for all of insecticides Chief Executive Officer Robert L. Krakoff lawn and garden uses beginning in 2003 Our understanding of the important role (see TurfGrass TRENDS, February 2001, which the invertebrate community plays Vice Chairman James M. Alic Pg. 15). In the mean time annual produc- in the turfgrass habitat has just started to tion levels will be reduced for the 2001- be elicited by a number of researchers. This VP-Finance, CFO & Secretary David W. Montgomery 2002 seasons. With the impending cancella- invertebrate community consists of an Executive Vice Presidents tion of Diazinon only one insecticide, Dylox array of predatory insects such as ants William J. Cooke (trichlorfon), will provide effective curative (Formicidae), ground beetles (Carabidae), Alexander S. DeBarr control of white grubs. Jean-Marc Levy and rove beetle (Staphylinidae). Also Daniel M. Phillips predatory mites (Mesostigmatidae), spi- Vice President & New product information ders (Araneida), and a host of decom- General Counsel A new insecticide from Syngenta is posers such as springtails (Collembola), Eric 1. Lisman planned for introduction in 2001. The mites (Orbatidae) and earthworms (Lum- Treasurer and Controller Adele D. Hartwìck ORGAIUOPHOSPATES CARBAMATES BIORATIOIUALS 1990 • Dylox • Sevin • Milky disease nematodes • Oftanol • Turcam • Mainstay • Diazinon • Dursban • Triumph • Mocap 2001 • Dylox • Sevin • Milky disease nematodes Naturalis • Diazinon* • Merit • Mach 2 • Meridian** * DIAZINON CANNOT BE APPLIED TO GOLF COURSE TURF OR SOD FARMS ** MERIDIAN IS EXPECTED TO OBTAIN EPA REGISTRATION IN 2001 bricidae) are part of this turf grass commu- a significant reduction of predators such as nity. spiders and rove beetles for a period of six All of these invertebrate play an integral weeks. Also, work by Vavrek and Niem- role whether it be in natural control, czyk (9) demonstrated how Oftanol enhancing soil tilth and productivity or caused significant reduction to mites, offering a stable food source for various springtails and rove beetles for periods predatory groups of arthropods. ranging from 13 to 43 weeks. Other Researchers at the University of Ken- researchers (1,3,5,11) have also reported tucky (8) were first to quantity the level of on the adverse affect organophosphate and predation in the turfgrass community. carbamate insecticides have on the inver- Predators such as spiders, ants, rove beetles tebrate community. and ground beetles were responsible for Rove beetles have been reported to be consuming up to 73% of Japanese beetle one of the principal egg predators of the eggs. Zenger and Gibb (10) have reported black turfgrass ataenius beetle in Michi- egg predation by the thief ant and various gan( Smitely, personal communication). rove and ground beetles to reach mortali- Their populations seem to be relatively ty levels of 65%. stable in habitats which have an adequate The use of the older, broad spectrum food supply of springtails. However, if insecticides have been shown to have an springtail populations decline, then rove adverse effect on a number of different beetle populations will also decrease thus predator groups and various decomposer resulting in lower predation of ataenius groups. Cockfield and Potter (2) reported eggs. Dursban and Oftanol applications caused The interrelationship of predator-prey relationships at a lower level provides species (4). This synergistic effect may be insight into the complexity of the turfgrass due to the way Merit alters the defensive habitat and in its natural control system behavior of white grubs to nematode which can be easily altered by the appli- attack. No adverse effect was observed to cation of broad spectrum insecticides. the entomopathogenic nematode, Het- The new soil insecticides such as Mach erorhabditis marelatus, when Mach 2 was 2 and Merit are reported to have less applied (7).