regulations impose guidelines to maintain aesthetic property values, which often influence homeowners’ needs to maintain lawns (Jenkins, 1994). However, arguably the most influential is the social pressure from neighbors who often ensure enforce- ment of lawn regulations, to which homeowners often conform (Byrne, Reviews 2005). There are an estimated 40 million acres of nonnative grass lawns in the United States, covering almost 2% of land, making it the largest irrigated monoculture plant system in the coun- try (Milesi et al., 2005; Tallamy, A Review of Organic Lawn Care Practices and 2007). Lawns are often high-input systems, requiring significant amounts Policies in North America and the Implications of time, monetary, and chemical in- vestments to maintain aesthetic prop- of Lawn Plant Diversity and Insect Pest erty value (Robbins et al., 2001). The prevalence of turf cover throughout Management the United States and a low tolerance for weed and insect pests coincides Sam Marshall1,4, David Orr1, Lucy Bradley2, with an increase in the use of synthetic chemicals (Alumai et al., 2008). Con- and Christopher Moorman3 ventional lawn management strategies are calendar-based applications of syn- thetic chemical inputs of fertilizers, ADDITIONAL INDEX WORDS. turfgrass, landscape herbicides, and insecticides (Alumai SUMMARY. There are 40 million acres of turfgrass lawns throughout the United et al., 2008; Bormann et al., 1993) States, most of which are managed under chemical-intensive pest and fertilizer and have been associated with environ- programs. ‘‘Organic lawn care’’ is being adopted more widely; however, unlike the mental pollution and human health formally defined policies and regulations that govern organic agriculture, the label risks [Robbins and Sharp, 2003a; organic lawn management has not been formally defined and is used to describe U.S. Geological Survey (USGS), a variety of practices. Neighborhoods, cities, states, and provinces across North 1999]. As a result, strategies using America are adopting policies regulating the use of pesticides and fertilizers in the landscape. In addition, a small but growing number of public institutions and integrated pest management (IPM) individual consumers are successfully adopting alternative lawn care methods, or ‘‘organic’’ practices have garnered including organic lawn care. Although perceived as environmentally friendly, the increased attention as management effects of organic management on insect diversity and pest management remain alternatives (Alumai et al., 2008). understudied. Organic lawn management may lead to increased lawn plant di- Some individual consumers and versity, which in agroecosystems has enhanced ecological services provided by public institutions have adopted alter- beneficial insect species. Effects of vegetative diversity on lawn pest management are native lawn management strategies, less clear. Vegetative complexity and increased plant diversity in urban landscapes which have been promoted as a way may enhance insect predator efficacy. The diversity of predatory insects varies to prevent potential negative environ- between turfgrass varieties in response to prey populations. Mortality of insectiv- mental consequences of the overuse or orous and granivorous ground beetles (Carabidae) while not directly impacted by pest management programs in turfgrass may be indirectly impacted by a reduction misuse of pesticides (Henderson et al., in the prevalence of plant species that provide alternative food resources. Previous 1998). The growing interest in lawn studies have focused on herbivorous insects as well as predatory and parasitic insects management alternatives has led to that feed on them. Future studies should assess how lawn plant diversity resulting changes in public policies which ban from organic management practices might impact insect communities in turfgrass. the use of cosmetic pesticide applica- tions and favor the adoption of lawn s a result of the economic suburban) area in the United States alternatives (Vickers, 2006), including boom in the mid-20th century, increased by 12% each year (U.S. organically managed green spaces Athe middle-class changed its Census Bureau, 2012). In 2012, over (Alumai et al., 2008). way of life, increasing urban sprawl 80% of the U.S. population lived in Although organic management due to movement away from city urban areas (U.S. Census Bureau, programs are offered as an alternative centers (Robbins and Sharp, 2003a). 2012). Construction of homes and to traditional lawn care, their impact From the mid-1950s to 1986, almost buildings often leads to a loss of on arthropod diversity and pest man- 69 million acres of natural habitat was natural vegetation (Blubaugh et al., agement is poorly understood. A goal converted to urban or suburban areas 2011), which is often replaced with of commercial IPM or organic man- (Grey and Deneke, 1986). From turfgrass systems (Tallamy, 2007). agement is to enhance the overall 2000 to 2010, urban (urban + Public policies and local housing aesthetic quality of lawns, which
• August 2015 25(4) 437 REVIEWS includes suppression of pests that in- inspection to ensure USDA regulations general public (Pralle, 2006a). In vade turf (Alumai et al., 2008). Since are still being met. 1992, Spraytech (Calgary, AB) and little is known about the effects of Except for cases where turf is Chemlawn (Memphis, TN) filed suit organic lawn management on arthro- grown commercially for sod or seed against Hudson, QC, claiming that pod communities, this article reviews production, lawns are not agricul- municipalities did not have the right literature pertinent to organic lawn tural commodities and so their man- to impose bans on chemicals which care, highlighting studies that have agement is not regulated other than hadbeenapprovedforusebyna- assessed the effects of turf variety by local municipal and homeowner tional and provincial governments and management practices on insect association aesthetic rules. Because (Pralle, 2006a). The two companies communities. To put this informa- there has been no groundswell of brought the case to Quebec’s Supe- tion into context, the article begins support for consistent definitions of rior Court, where the decision of with an assessment of what organic organic lawn management and accom- Hudson to ban nonessential applica- lawn management means and the panying regulations like for agricultural tions of pesticides was upheld (Pralle, history of public policy regard- commodities, there is no national 2006a). Eventually, the case went to ing its implementation in North definition or regulation of organic the Canadian Supreme Court, and in America. lawn care. This article refers to or- 2001 it upheld Hudson’s right to ganic lawn management with the ban nonessential use of chemicals understanding that there are many (Pralle, 2006a). It also extended its Defining Organic Lawn varying definitions. decision, and included the right of Management all local municipalities through- The U.S. Department of Agricul- Relevant Public Policy in North out Canada to adopt bylaws that ture (USDA) defines organic agricul- America banned cosmetic chemical applica- ture as ‘‘. an ecological production tions in public and privately owned management system that promotes and Grassroots organizations through- green spaces (Pralle, 2006a). By enhances biodiversity, biological cycles, out North America are pushing institu- 2005, there were 70 municipal by- and soil biological activity. It is based tions as well as local and regional laws which banned the nonessential on minimal use of off-farm inputs and governments to restrict the use of use of pesticides in Canada (Pralle, on management practices that restore, pesticides and adopt organic or sim- 2006a). maintain, and enhance ecological har- ilar management policies for public In 2003, the Canadian province mony’’ (USDA, 1995). The USDA spaces. These changes are being of Quebec adopted a pesticides man- National Organic Program (NOP) ad- made primarily because of perceived agement code in an attempt to miti- ministers and publishes organic regula- public health concerns, even though gate deleterious effects from the tions with input from the public and the consequences of these policies overuse of pesticides in publicly man- the National Organic Standards Board. may not yet be fully understood aged green spaces. The code was re- Before being certified as organic, farms (e.g., labor requirements, pest man- vised several years later, and in 2006 must undergo a 3-year transition pe- agement). The following section re- extended its guidelines to include riod in which organic production prac- views these policy changes to put the commercial as well as privately man- tices are followed, and documentation discussion of organic lawn manage- aged lawns in urban areas (Province of must be provided that no unapproved ment into context. Quebec, 2012). Guidelines of the products or practices were used in the code mandate that all applicators, production system. Producers must Public Policies in Canada whether for commercial or private then submit an application and fees to In 1991, the Montreal suburb of (residential) use, file for an applica- a USDA-accredited certifying agent Hudson, QC was the first municipal- tion permit stating just cause and (state departments of agriculture or ity to adopt a bylaw prohibiting the purpose for application of pesticides private organizations). After an on-site nonessential use of pesticide applica- (Province of Quebec, 2012). Follow- inspection and review of the application tions in public and private properties ing application of pesticides, signs indicate the producer is in compliance (Pralle, 2006a; Robbins and Sharp, must be posted notifying the public with USDA organic regulations, the 2003b). In Canada, national and pro- that pesticides have been applied with certifying agent will issue an organic vincial governments oversee the types the maximum allowable reentry pe- certificate. Producers are required to and safety of chemicals that can be riod, depending on the type of chem- provide annual updates to the certifying sold (Pralle, 2006a). While this power ical that has been applied (Province of agent,whoperformsanannual was not explicitly stated for local Quebec, 2012). municipalities, they did have the In 2004, the city of Regina in the power to adopt bylaws that protected Canadian province of Saskatchewan 1Department of Entomology, North Carolina State University, 1110D Grinnells Hall, Raleigh, NC the health and well-being of the adopted the cosmetic pesticide policy, 27695 2Department of Horticultural Science, North Caro- Units lina State University, 128 Kilgore Hall, Raleigh, NC 27695 To convert U.S. to SI, To convert SI to U.S., multiply by U.S. unit SI unit multiply by 3Department of Forestry and Environmental Re- sources, North Carolina State University, Box 7646, 0.4047 acre(s) ha 2.4711 Turner House, Raleigh, NC 27695 3.7854 gal L 0.2642 4Corresponding author. E-mail: wsmarsh2@ncsu. 40.7458 gal/ft2 LÁm–2 0.0245 edu. 25.4 inch(es) mm 0.0394
438 • August 2015 25(4) which prevents the use of cosmetic placed bans on aerial applications of coordinator (Town of Carrboro, De- pesticide applications in publically pesticides (Pralle, 2006b). In 1991, the partment of Public Works, 1999). The managed green spaces in favor of an ordinance was challenged by farmers, town also adopted the Least Toxic IPM IPM program (Hjertaas, 2007). Un- ranchers, and the timber industry, Manual, which provides municipal land like the other Canadian provinces, claiming that the Federal Insecticide, managers a protocol for developing and Saskatchewan does not have bylaws Fungicide, and Rodenticide Act using preventative control measures for or restrictions on cosmetic pesticide (FIFRA) preempted local regulations. pests, using the least toxic form of use (Hjertaas, 2007). However, the U.S. Supreme Court chemical available (Town of Carrboro, Ontario, Canada adopted a ban ruled that FIFRA did not prevent the Department of Public Works, 1999). on the nonessential use of chemical regulation of pesticides by local gov- To date, the IPM policy for Carrboro pesticides on lawns in 2008 (Suzuki ernments and upheld decisions by only applies to publicly managed green and Moola, 2009). The Ontario Pesti- municipalities to pass pesticide bans spaces, and is not mandatory for resi- cides Act provides legal and regulatory (Pralle, 2006b). The chemical indus- dents living within the town limits policies that require all commercial try lobbied successfully at the federal (Town of Carrboro, Department of pesticide applicators receive proper level for state preemption laws, which Public Works, 1999). training in the application and han- meant that state laws could override Voorhees, NJ, requires all public dling of pesticides (Province of stricter pesticide policies adopted at properties and township parks to be Ontario, 2009). The cosmetic pesti- the local level (Pralle, 2006b). managed under an IPM program and cides ban was added to the Pesticides Local governments, as a result of requires postage of signs in areas that Act in Apr. 2009 and establishes a clear state preemption laws, were therefore have been treated with pesticides (Be- set of guidelines that commercial pes- slower to adopt pesticide-use regula- yond Pesticides, 2008). New Jersey is ticide applicators must follow to reduce tions because of legal conflict with state one of 21 states that require home- the nonessential use of pesticides laws (Pralle, 2006b). One of the first owners to display postings in lawns throughout public, residential, and nonessential pesticide bans came in where chemicals have been used to privately owned areas (Province of 2009, as a response to public and treat turf; it is also one of 14 states Ontario, 2009). The policy is man- environmental health concerns of the that require state agencies and indi- dated throughout the entire province overuse of pesticides in Chicago, IL city vidual companies to establish a regis- of Ontario, but does not include parks. The Chicago Park District part- try for people to sign up for prior consumer-managed lawns (Province nered with the Safer Pest Control Pro- notification when adjacent properties of Ontario, 2009). ject to ‘‘naturally’’ manage public green are being treated with chemical sprays Alberta mandated a policy simi- spaces in the greater Chicago area (Chi- (Beyond Pesticides, 2012a). To date, lar to Ontario’s in 2008 and in 2009, cago Park District, 2011). The focus over 30 communities in New Jersey New Brunswick and Prince Edward of the project was to eliminate the have adopted IPM strategies or have Island followed suit by adopting pes- nonessential use of synthetic pesticides banned cosmetic pesticide use alto- ticide use restrictions in publicly man- and fertilizers, to mitigate public health gether (Bernardsville News, 2012). aged green spaces (Christie, 2010). concerns with the overuse of chemicals The Cuyahoga County Council Most recently, Nova Scotia adopted (Chicago Park District, 2011). in Ohio recently approved a policy the Nonessential Pesticides Control In King County, WA, 102 of the that limits the use of chemical pesti- Act, which restricts the sale and use of 189 public green spaces are pesticide cides on the public green spaces in an nonessential pesticides for lawn care, free, and 87 are pesticide reduced attempt to reduce nonessential pesti- including residential and publically (Enumclaw Courier-Herald, 2012). cide applications (Beyond Pesticides, managed green spaces (Government Ogunquit, Rockport, and several 2012b). The policy promotes IPM of Nova Scotia, 2011). The province other communities throughout Maine strategies, emphasizing scouting and of Manitoba is currently considering currently prohibit chemical-intensive proper identification of pest prob- similar bans on cosmetic pesticide landscaping in public areas (Beyond lems, and the judicious use of chem- applications throughout the entire Pesticides, 2010). ical applications, only when pest province (Winnipeg Free Press, IPM practices and policies have pressure poses an immediate threat 2012). As of 2010, almost 180 mu- been adopted in publicly managed to public health and when other nicipalities throughout most Cana- green spaces throughout the United alternatives to pest control are not dian provinces have adopted similar States. In Mar. 1999, Carrboro, NC, available (City Council of Cuyahoga bans on pesticide use for cosmetic adopted an IPM program for all publi- County, OH, 2011). The restrictions purposes (Christie, 2010). cally managed properties within the also require that advanced public no- town. The plan was adopted as a result tice be given when chemical pesticides of the growing concern of the public are used in public spaces, and enforces Public Policies in the United health risks involved with cosmetic ap- the maximum reentry period follow- States plications of chemical pesticides to treat ing applications (City Council of In the United States, local and public green spaces (Town of Carrboro, Cuyahoga County, OH, 2011). state regulations have focused on resi- Department of Public Works, 1999). In 2007, as a response to public dent notification by lawn care compa- The program mandates that each de- and environmental health concerns of nies when pesticides were applied partment within the town government the overuse of pesticides in city parks, (Pralle, 2006b). In 1985, Casey, WI have a written IPM plan for the man- Greenbelt, MD, assembled an advisory enacted a pesticide ordinance that re- agement of municipal property and is committee to conduct a 2-year study quired permits for pesticide use and written with and reviewed by the IPM that assessed the monetary cost of
• August 2015 25(4) 439 REVIEWS pesticide usage within the city limits mechanical, and manual controls to for the organic management of green (Greenbelt City Council, 2012). Based reduce pest pressure. The advisory spaces, due to an increase in cost of on their findings, the committee de- board does allow use of chemical organic fertilizer as well as an increase termined that nonessential applications controls in the event of public emer- in labor costs from manual removal of of fertilizers and pesticides were expen- gencies (Town of Marblehead, ME, weeds (Chamberlin, 2012). Under sive and proposed to eliminate the 2001). The policy was disputed by the charter, ordinances proposed by cosmetic applications of pesticides in professional landscapers as well as citizen petitions cannot exceed avail- publicly managed green spaces and the school board, who claimed that able monetary funds of the city (City adopt more sustainable land manage- implementation of these practices of Durango, CO, 1986). The pro- ment practices to alleviate monetary would be more expensive and not as posal also allowed any individual cit- costs as well as public health concerns cost effective as a balanced approach izen the right to sue the city if there (Greenbelt City Council, 2012). In for managing turf (Capone, 2002). was failure to comply with the regu- 2012, Greenbelt, MD adopted the Camden, ME, passed the Pest lations within the ordinance (City of Sustainable Land Care Policy, which Management Policy, which empha- Durango, CO, 2012). On 21 Aug. bans all cosmetic uses of pesticides in sizes the use of organic practices to the proposal was vetoed by the city an attempt to phase out the unnecessary manage public green spaces (Town of council (Boardman, 2012). How- use of chemicals for turf treatment Camden, ME, 2008). The ordinance ever, in early Sept. 2012 the city (Riddle, 2011). Under the law, pro- prevents the use of pesticides on pub- council reached a compromise with fessional contractors and landscapers licly managed grounds, and operates advocates of the citizen group and must operate under an IPM or com- under organic practices, using cultural, voted to develop and evaluate a pro- pletely organic strategy for maintaining mechanical, and products approved by gram that minimized pesticide use turf. Some of these strategies include the Organic Materials Review Institute and would slowly phase in organic using plant varieties resistant to pest (OMRI) to deal with pest issues (Town management practices, rather than pressure, and using manual, mechani- of Camden, ME, 2008). The Healthy completely switch from conventional cal, and biological controls to deal with Turf and Landscape Policy, adopted by to organic management (Boardman, pest issues, such as weeds and insects the Village of New Paltz, NY, prohibits 2012). As an initial step to adopting (Riddle, 2011). IPM programs selec- the application of pesticides for aes- organic management strategies, the tively use chemical controls as a final thetic purposes on municipal proper- city council allotted a budget of option, when pests escape other forms ties and emphasizes the use of organic $36,000 to hire a consultant to de- of control [U.S. Environmental Pro- and cultural management practices as velop and estimate the cost of imple- tection Agency (USEPA), 2012]. preventative approaches to offsetting mentation of an organic program for In various states across the coun- pest problems in turfgrass (Village of all city parks throughout Durango try, public schools are adopting IPM New Paltz Board of Trustees, 2008). (Boardman, 2012). programs to manage school grounds. Similarly, the community of Wellfleet, Grassroots movements through- In 2004, New Jersey implemented MA limited the amount and types of out North America are pushing local a statewide New Jersey School IPM pesticides used for managing their governments to modify their land Program, which requires that all schools green spaces (Bragg, 2012) and re- management policies to address per- in the state manage their grounds under cently adopted the Municipal Organic ceived public health concerns over IPM practices and mandates that a min- Land Management Policy, which pro- pesticide applications. If this trend imum of 72-h advanced notice be given hibits the use of synthetic fertilizers on continues, it will become more im- to parents when pesticide applications public green spaces and other munic- portant to understand the conse- are made to school grounds (New ipal properties (Bragg, 2012). quences of these new policies. Jersey Department of Environmental In Durango, CO, under the cit- Protection, 2004). Since then, Califor- izen initiative petition provision of nia, Texas, North Carolina, and other the Durango City Charter (City of Organic Lawn Management states have adopted IPM programs for Durango, CO, 1986), residents pro- Practices managing school grounds (U.S. Envi- posed an Organic Land Management Because organic management in ronmental Protection Agency, n.d.). Program, which would reduce and lawns does not have any legal or In addition to outright bans on eventually eliminate the use of chem- regulatory guidelines, a variety of prac- pesticide use or implementing IPM ical fertilizers and pesticides through- tices have either been suggested by programs, some municipalities have out all city parks (City of Durango, authors or used by practitioners. Al- adopted organic management poli- CO, 2012). Further, the program though not supported by experimen- cies for publicly managed areas. In planned to implement organic turf tal studies, Tukey (2007) suggests 2001, the town of Marblehead, ME, management methods such as me- using materials for lawn management adopted the organic land manage- chanical and manual strategies to deal that are certified by OMRI as accept- ment policy for turfgrass, which was with pests (City of Durango, CO, able for organic agriculture including the first implementation of organic 2012), and only allows the use of fertilizers such as organic composts or policies to reduce and eventually pesticides in a case of public health teas, and commercially available prod- eliminate pesticide use on town- emergency, when other methods of ucts to treat turf pests. An extreme owned land (Town of Marblehead, control are unsuccessful (City of approach to creating an ‘‘organic ME, 2001). An organic pest manage- Durango, CO, 2012). lawn’’ is to replace turfgrass with a ment advisory board was assembled Opponents to the ordinance es- ‘‘no-mow’’ herbaceous groundcover to prioritize the use of cultural, timated substantial increases in cost alternative that may not require the
440 • August 2015 25(4) types of chemical and physical inputs soil quality, biological activity, and nu- savings in cost since converting to associated with traditional turf man- trient contents, and overall health of organically managed turf (N. Selby, agement (Tukey 2007). the organically managed turf vs. con- personal communication). Life cycle assessments by Morris ventionally managed turfgrass. After 8 Since Mar. 2012, the University and Bagby (2008) have suggested months, the organically managed test of Arizona managed 12 acres of open that ‘‘organic-centered’’ lawn man- plot had more nutrient cycling and grass in their central mall under or- agement reduces pesticide exposure supported more root growth, higher ganic practices, which includes appli- and pollution, and minimizes water nitrogen levels, and reduced need cations of aerated compost tea and the usage and runoff. Morris and Bagby for irrigation than control plots under elimination of pesticides and fertilizer (2008) also found that turf managed conventional management practices applications (M. Anderson, personal with an organic-centered approach (Raver, 2009). The internal landscape communication). Visual comparisons required 8.1 LÁm–2 of water for department maintains 65% (52 acres) of organic and conventionally man- irrigation annually per square meter of Harvard properties, which have been aged areas on Arizona’s campus have of lawn, as opposed to 903 LÁm–2 in managed organically since 2008; how- not yielded any notable differences in a conventionally managed lawn. The ever, landscape managers hope to con- the quality of turf between the test direct causes for the reduction in vert all 80 acres of Harvard University plots; however, they are currently irrigation were not evaluated. How- to organic practices (Raver, 2009; W. awaiting soil analysis results to com- ever, studies in organic agricultural Carbone, personal communication). As pare the soil biotic composition be- systems have shown that an increase a result of the switch from conventional tween the organic and conventionally in soil biomass increases water reten- to organic landscape practices the uni- managed areas (M. Anderson, personal tion, which ultimately leads to versity noted a first-year savings of 2 communication; Tukey, 2012b). Thus a higher tolerance in drought condi- million gallons of water from reduced far, widespread adoption has been tions (Pimental et al., 2005). Increas- irrigation, and $45,000 in landscape prevented due mainly to high labor ing organic matter in lawn soils may waste removal fees from on-campus expenditures and lack of adequate lower the risk for pest damage by composting (Raver, 2009). equipment required to maintain the supporting healthier root systems, so In 2011, The University of 12-acre plot; however, they are seeking that turfgrass has a higher tolerance Colorado in Boulder began the first alternative, more efficient delivery for pest pressure and damage, and full year of implementation of organic methods similar to the one at the a reduced need for pesticides (Bruneau, compost tea applications through their University of Colorado, Boulder, which 1997). In a comparison of management irrigation system as a way to increase uses the irrigation system for applica- programs, Alumai et al. (2008) found soil nutrients and soil microbial tions of compost tea (M. Anderson, that organic management programs populations, with the intentions of personal communication). resulted in fewer herbicide and insecti- minimizing and eventually eliminat- cide treatments than conventional pro- ing the need for synthetic turf inputs grams, and thus a reduction in annual (Tukey, 2012a; D. Inglis, personal Organic Practices in Golf maintenance costs, with comparable communication). Any differences in Courses aesthetic qualities to a conventionally annual costs associated with conven- There are several examples of golf managed system. tional vs. organic programs will be courses taking organic approaches to Bruneau (1997) suggests four examined by comparing results from managing their greens. A golf course practices for organic management of soil bioassay tests, including biolog- in Lubbock, TX, recently converted insect pests: 1) prevent insect damage ical soil fauna composition pre- and 80% to 90% of its fairways and greens by nurturing a healthy lawn to better postimplementation of the organic to organic care (Morris, 2011). For tolerate pest damage; 2) reduce tea applications (D. Inglis, personal more than 50 years prior, the land that thatch layer to limit favorable condi- communication). the course now occupies was under tions for insect habitation; 3) properly In 2009, Swarthmore College intensive management as a cotton identify pest insects vs. nonpests; 4) started managing 5 acres of their farm and soil quality was a major con- spot treatment with pesticides (e.g., grounds under organic practices to cern for the owners. Over a period of 5 treating only when and where it is compare the differences, if any, with years, the course converted 270 acres needed) instead of broadcast applica- plots under conventional management of intensively managed greens to low- tions. To help with the latter two strategies (Smith, 2011). Root growth input practices. The application of practices, Bruneau (1997) presents increased from 3.5 to 5.5 inches on compost teas and other organic soil identification and scouting informa- average since converting to organic amendments resulted in using almost tion for major turfgrass pests. methods; however, weed pressure 1/4 million fewer gallons of water and visual greenness is not noticeably used per day than other courses under different between conventional and conventional management, despite Organic Lawns on University organically managed plots (N. Selby, being 120 acres larger (Morris, 2011). Campuses personal communication). While syn- The Vineyard Golf Club in Mar- In Mar. 2008, Harvard University thetic fertilizer and pesticide expense tha’s Vineyard, MA thought to be the converted a 1-acre plot of convention- has been eliminated, it has been only completely organic golf course ally managed turfgrass into organic replaced with compost screening, or- in the country, uses no synthetic pes- lawn (Raver, 2009). The objective was ganic fertilizer and seed purchases, and ticides or fertilizers to manage the to eliminate use of synthetic chemicals staff training to monitor soil biology greens, fairways, and other green used to manage turf and compare the and as a result, there have been no spaces throughout the grounds
• August 2015 25(4) 441 REVIEWS
(Pennington, 2010). Before construc- complexity may offer sources of refuge, fall armyworm and japanese beetle grub tion of the golf course, surrounding alternative food sources, greater vari- across treatment types (Braman et al., subdivisions expressed concern over the ability in microclimates, or increase the 2002). Also demonstrated was an in- potential hazards of using synthetically abilitytolocatepreyeffectively,andthe crease in the occurrence of beneficial produced chemicals to control the ability to avoid intraguild predation parasitic wasps (Hymenoptera) in turf- greens (Pennington, 2010). This ulti- (Landis et al., 2000; Langellotto and grass plots surrounded by diverse flower mately resulted in the Martha’s Vine- Denno, 2004). mixes; however, their efficacy for insect yard Commission allowing the course Habitat complexity has also been pest control was not evaluated (Braman to be constructed under the stipulation studied in urban systems (Raupp et al., et al., 2002). that no synthetically produced chemicals 2010; Shrewsbury and Raupp, 2000, N ATURAL CONTROL FROM could be used to manage the grounds 2006). Urban systems often involve less PARASITOIDS AND PREDATORS. Pedigo (Pennington, 2010). frequently disturbed perennial plantings and Rice (2006) define natural con- and have higher plant diversity than trol as ‘‘. the suppression of pest natural areas (Raupp et al., 2010). As populations by naturally occurring Arthropod Management in a result, urban areas may experience biotic and abiotic factors.’’ Turfgrass Turfgrass Systems fewer pest outbreaks due to an increase habitats have the ability to support It is not yet clear what the effects of in food web stability (Raupp et al., 2010; diverse arthropod communities in- organic lawn management on econom- Shrewsbury and Raupp, 2000, 2006). cluding herbivores, predators, and ics, water management, soil quality, Shrewsbury and Raupp (2006) demon- detritivores (Potter, 1993). A review aesthetics, and weed management, but strated lower populations of azalea lace by Potter and Braman (1991) high- a few institutions are currently evaluat- bug (Corythuca sp.) pests in habitats lighted common pests in turfgrass ing organic practices before full-scale with more complex vegetative surround- and their management, including implementation. However, none are ings. Vegetatively complex habitats sup- the use of IPM programs and biolog- evaluating the effects of these practices port greater populations of endemic ical control agents. They suggested on insect pest management, even natural enemies and generalist predators, that high-intensity management sys- though there is a concern that organi- as well as alternative prey food sources tems may experience more frequent cally managed lawns may have more (Shrewsbury and Raupp, 2006). pest outbreaks because of repeated pest problems (Chamberlin, 2012). In golf courses, Frank and insecticide applications, which have PLANT MANAGEMENT IN AND Shrewsbury (2004) showed that con- been shown to negatively affect AROUND TURF. Organically managed servation strips of different flowering natural enemies important in IPM lawns may be expected to have higher plants near turfgrass fairways increased and biological control (Potter and plant species diversity, which has been the diversity of both predatory and Braman, 1991). Low-intensity turf- shown to increase arthropod popu- parasitic beneficial insects. This study grass systems appear to be more stable lations in other systems (Andow, demonstrated an increase in predation due to natural enemy predation and 1991). While arthropods have been of black cutworm (Agrotis ipsilon) parasitism, and as a result, experience studied in turfgrass systems, no stud- when conservation strips were planted fewer pest outbreaks (Potter and Bra- ies have directly evaluated the effects near fairways; however, increase in man, 1991). of increased lawn plant species diver- predation was not necessarily corre- Braman and Pendley (1993) cata- sity on their populations. lated with an increase in predator logued ground-dwelling arthropod Plant diversity has been evaluated abundance suggesting that abundance fauna in centipedegrass (Ermochloa in agricultural systems, and has been alone might not be an accurate mea- ophiuroides) under high- and low- shown to enhance ecological services surement for pest control in turfgrass intensity management conditions. High- provided by beneficial arthropods (Frank and Shrewsbury, 2004). intensity systems were based on (Marino and Landis, 1996; Menalled Similarly, Braman et al. (2002) regular applications of chemical in- et al., 1999). Also studied are the effects evaluated the potential for wildflower secticides, while low-intensity sites of increasingly complex environments borders to increase abundance and im- received no treatment for the 2-year that increase habitat suitability for ben- pact of beneficial arthropods in the duration of the study. They concluded eficial arthropods by providing alterna- landscape and to determine whether that different types of arthropods tivefoodresourcessuchasnectarand natural enemies and pest-resistant turf- responded differently to management pollen (Landis et al., 2000). Theis et al. grass varieties could be compatible in practices. For instance, ground beetles (2003) demonstrated that the amount the control of japanese beetle grub and ants (Formicidae) were found in of noncrop vegetation in agricultural (Popillia japonica)andfallarmyworm greater numbers in the low inten- landscapes was directly correlated with (Spodoptera frugiperda). This study sity sites, presumably because of the parasitism of agricultural pests, and demonstrated greater abundance of greater number of alternative herba- concluded that landscapes with more some predatory arthropods such as ceous resources available (Braman and than 20% of noncrop vegetation had big-eyed bugs (Geocorus sp.) and fo- Pendley, 1993). In the high-intensity meaningful reductions in insect herbi- liar-dwelling spiders (Aranae) in turf- plot, parasitic wasps, and spiders were vore populations and damage to crop grass plots surrounded by flowering adversely affected immediately fol- plants. As habitat complexity and sur- plant borders than in those surrounded lowing insecticidal applications, while rounding noncrop vegetation increases, by mulch. Although abundance and rove beetle (Staphylinidae) popula- the stability of that vegetation commu- diversity of these predators was influ- tions were positively impacted due to nity likely will increase (Theis et al., enced by increased plant diversity, there the increase in decaying vegetation 2003). An increase in vegetative was no difference in predation rates of (Braman and Pendley, 1993). The
442 • August 2015 25(4) occurrence and abundance of parasitic positively impacted by weed density, The compatibility of resistant wasps in turfgrass has also been docu- noting the tendency of these groups to turfgrass varieties with beneficial ar- mented (Braman and Pendley, 1993; switch feeding habits based on prey thropods for control of insect pest Braman et al., 2002; Held, 2005; availability (Joseph and Braman 2009). populations in turfgrass has also been Joseph and Braman, 2009, 2011). This study suggested how knowledge evaluated in field studies on predators Joseph and Braman (2009) docu- of turfgrass variety and potential re- (Braman et al., 2003) and parasitic mented that turfgrass variety influenced sistance to pests may enhance benefi- wasps (Braman et al., 2004). Braman which types of parasitic wasp were cial arthropod populations for more et al. (2003) evaluated the compati- present, likely due to the host specificity effective pest control in turfgrass sys- bility of resistant turfgrass varieties of parasitic wasps and relative abun- tems (Joseph and Braman, 2009). with predatory big-eyed bugs (Geo- dance of primary hosts. Although this It is worth noting that overall coris uliginosis). This study demon- study indicated an abundant and di- plant diversity was not assessed in this strated that resistant zoysiagrass alone versity of parasitic wasps, their efficacy study, so conclusions could not be kept fall armyworm populations low for managing insect pest populations made as to how the diversity of plant and the addition of big-eyed bugs had in turfgrass was not evaluated. communities within lawns impact ar- no effect on pest numbers (Braman To determine how direct impacts thropod abundance and diversity. et al., 2003). In turfgrass varieties of management programs might im- I NSECT PEST RESISTANT susceptible to fall armyworm, this pact ground beetles, Blubaugh et al. TURFGRASS VARIETIES. Warm-season same study demonstrated no effect (2011) compared beetle diversity turfgrass varieties have been evaluated of predators on effectively managing across four lawn management pro- for their resistance to a variety of phy- pest populations (Braman et al., grams: 1) high-input, calendar-based tophagous pest insects (Quisenberry, 2003). consumer program, based on recom- 1990; Reinert et al., 2004; Shortman Braman et al. (2004) evaluated mendations from a professional lawn et al., 2002). Employing resistant turf- the compatibility of resistant turfgrass care company, 2) an IPM program, 3) grass varieties may help reduce damage varieties with parasitic wasps of fall an organically managed program, and from insect pests, which could lead to armyworm. This study demonstrated 4) a no-input program (Caceres et al., a reduction in the need for pesticides a lower percentage of parasitized 2010). Populations of ground beetles (Braman et al., 2000a; Quisenberry, fall armyworm in turfgrass varieties were monitored and the species were 1990; Reinert et al., 2004). highly resistant to fall armyworm categorized as either predatory, gra- The efficacy of pest management (Braman et al., 2004). Although per- nivorous, or omnivorous (Blubaugh in resistant turfgrass varieties has been cent parasitism was decreased with et al., 2011). Ground beetle commu- evaluated as a stand-alone strategy for increased levels of turfgrass resis- nities were not directly impacted by insect pest management (Braman tance this study demonstrated higher management regime. Consumer and et al., 2000a). Laboratory studies dem- levels of parasitism in bermudagrass IPM programs had fewer ground onstrated that two varieties of com- (Cynodon sp.) varieties with moderate beetle populations than no-input sys- mercially available zoysiagrass (Zoysia levels resistance (Braman et al., tems. The most prevalent weed species sp.) had high levels of antibiosis on fall 2004). present [white clover (Trifolium repens), armyworm larvae (Braman et al., dandelion (Taraxacum officinale), and 2000a), and two commercially avail- Discussion crabgrass (Digitaria ischaemum)] did able varieties of turfgrass had moderate Various interpretations of or- have a slightly positive impact on resistance to mole cricket (Gryllidae) ganic lawn care exist with no clear weed-feeding beetles, indicating that damage (Braman et al., 2000b). consensus of what exactly constitutes a reduction of weed species through Anderson et al. (2006) evaluated organic lawn management. Organic the use of herbicidal treatments might the resistance of several commercially lawn care might be considered a laissez- have a negative, indirect impact on available warm-season turfgrass varie- faire approach that lets weeds and granivorous species of ground beetle ties to multiple chinch bug species turfgrass cohabitate the same area, or communities (Blubaugh et al., 2011). (Blissus sp.). This study demonstrated it could be viewed as active manage- Joseph and Braman (2009) com- that ‘Floratum’ st. augustinegrass ment that uses only OMRI-approved pared natural enemies and their poten- (Stenotaphrum secundatum)was products. The common theme in all tial prey abundance in four common highly resistant to southern chinch organic lawn management programs warm-season turfgrass varieties and bug (B. insularis) whereas ‘Raleigh’ to date is the desire to avoid use of concluded that turfgrass type influ- and ‘Amerishade’ varieties were only synthetic chemicals, especially pesti- enced relative abundance of herbivo- moderately resistant to southern chinch cides. Because lawns are not consumed, rous and predatory hemipterans, likely bug (Anderson et al., 2006). Demon- there is no federal agency responsible due to the availability of preferred, more strated further was a high level of re- for their regulation, and there are no nutritious primary and non-preferred, sistance of ‘Floratum’, ‘Amerishade’, marketing advocates demanding con- but abundant alternative food re- and ‘Raleigh’ varieties to the chinch sistency in definition or regulation. As sources. Among all types of arthropods, bug species B. occidus (Anderson et al., a result, it is unlikely there will be species evenness and diversity were sig- 2006). Results of this study suggested a consensus any time soon on what, nificantly impacted by turfgrass variety that selection of turfgrass varieties with specifically, constitutes organic lawn (Joseph and Braman, 2009). These resistance to multiple species of phy- management. authors also reported that relative tophagous insect pests should be used Interest in organic lawn manage- population density of predatory bugs to mitigate pest damage (Anderson ment throughout North America is (Geocoridae and Miridae) was et al., 2006). growing, and a number of entities
• August 2015 25(4) 443 REVIEWS have adopted pesticide restrictions, may enhance pest control from natu- to weed cover in a turfgrass ecosystem. bans, or organic management prac- ral enemies (Frank and Shrewsbury, Environ. Entomol. 40:1093–1101. tices in public spaces. Legal disputes 2004); however, this may not always Boardman, J. 2012. Do-over in Durango: between advocacy groups in some of be the case (Braman et al., 2002). To Western town goes organic after all. 2 July these cases have progressed all the way date, however, no studies have evalu- 2015.
444 • August 2015 25(4) • August 2015 25(4) 445 REVIEWS com/2009/09/24/garden/24garden. 2011-10-21/news/30305536_1_ on its lawns. 2 July 2015. 446 • August 2015 25(4)