MEGADRILOGICA Volume 16, Number 7, June 2014

Transcription

1 Printed in Canada ISSN MEGADRILOGICA Volume 16, Number 7, June 2014 EARTHWORMS (OLIGOCHAETA: LUMBRICIDAE) INVADE LAWN BOWLING GREENS IN THE WATERLOO REGION OF ONTARIO, CANADA. John Warren Reynolds Oligochaetology Laboratory, 18 Broadview Court, Kitchener, ON Canada N2A 2X8 and Research Associate, New Brunswick Museum, Saint John, NB Canada E2K 1E5 ( ca) ABSTRACT Earthworm populations are becoming a problem at a number of bowling greens in the Waterloo Region, Ontario (District 7). Six of the eight lawn bowling clubs have soil based greens which are inhabited by Lumbricus terrestris. Two of the clubs have sand based greens where one club has no earthworms and the other has Aporrectodea rosea and Ap. tuberculata. A brief description with photographs on the construction of a sand based green is included. A discussion of the factors which relate to the general improvement of the soil condition by earthworms is presented. Chemicals which are highly toxic to earthworms and suitable for controlling populations associated with lawn bowling greens are listed. Key words: Waterloo Region, Oligochaeta, Lumbricidae, Aporrectodea rosea, Ap. tuberculata, Lumbricus terrestris, lawn bowling greens. RÉSUMÉ Les populations de vers de terre deviennent un problème pour un certain nombre de terrains de boulingrin dans la région de Waterloo, Ontario (Secteur 7). Six des huit clubs ont des terrains à base de terre qui sont habités par Lumbricus terrestris. Deux clubs ont des terrains à base de sable, dont un n'a pas de vers de terre et l'autre a Aporrectodea rosea et Ap. tuberculata. Une brève description de la construction d'un terrain à base de sable est incluse, avec des photographies. Une discussion des facteurs ayant trait à l amélioration générale de l'état des terrains en présence de vers de terre est présentée. Une liste des produits chimiques qui sont très toxiques pour les vers de terre et qui peuvent être utilisés pour leur contrôle est également incluse. Mots-clé: Région de Waterloo, Oligochaeta, Lumbricidae, Aporrectodea rosea, Ap. tuberculata, Lumbricus terrestris, boulingrins. RESUMEN Las poblaciones de lombrices se están convirtiendo en un problema en una serie de campos de bowling en la región de Waterloo, Ontario (Distrito 7). Seis de los ocho clubes tienen greens sobre base de suelo los cuales están habitados por Lumbricus terrestris. Dos de los clubes tienen greens sobre base de arena, un club no tiene lombrices de tierra, el otro tiene Aporrectodea rosea y Ap. tuberculata. Se incluye una breve descripción con fotografías de la construcción de un green sobre base de arena. Se da una discusión sobre los factores que se relacionan con las lombrices de tierra y si mejora en general las condiciones del suelo. También se presenta una lista de productos químicos que son altamente tóxicos para las lombrices de tierra y que pueden ser utilizados para su control. Palabras clave: Región de Waterloo, Oligochaeta, Lumbricidae, Aporrectodea rosea, Ap. tuberculata, Lumbricus terrestris, campos de bowlings. LÝ THUYẾT Thành phần giun đất đang trở thành vấn đề tại một số sân chơi bowling trên cỏ ở Vùng Waterloo, Ontario (Khu 7). Sáu trong số tám câu lạc bộ ở đây có sân cỏ trồng trên đất trong đó có giống giun đất Lumbricus terrestris sinh sống. Hai câu lạc bộ có sân cỏ trồng trên cát, một câu lạc bộ không có giun đất, một câu lạc bộ còn lại có giống giun đất Aporrectodea rosea và Ap. tuberculata. Trong đây có kèm theo phần giải thích ngắn gọn hình chụp về công trình xây cất sân cỏ trồng trên cát. Sự thảo luận về những yếu tố liên quan đến việc giun đất cải thiện tổng quát tình trạng của đất đã được trình bày. Ngoài ra còn kèm theo bản liệt kê những hóa chất độc hại đối với giun đất có thể dùng để kiểm soát số lượng giun đất. Từ Ngữ Chính: Waterloo Region, Oligochaeta, Lumbricidae, Aporrectodea rosea, Ap. tuberculata, Lumbricus terrestris, sân chơi bowling trên cỏ.

2 70 Earthworms invade Lawn Bowling Greens INTRODUCTION Earthworms are usually regarded as friends of good grasses. Generally earthworms improve the condition of soils according to Reynolds (1973, 1994) by: Organic matter decomposition Some species (e.g., Lumbricus terrestris actually take the leaves and surface debris and physically or mechanically break them apart, which enables microorganisms to complete the decomposition. Other species, which are "soil eaters," chemically alter the organic matter as it passes through their intestines. The breakdown and incorporation of organic matter into the soil increases its water-holding capacity for use by other plants and animals. Soil neutralization As soil is passed through the intestines of the earthworms. their calciferous glands secrete calcium compounds that raise the ph of the material nearer to the neutral state. The less acidic the soil, the more easily chemical reactions take place. These reactions are necessary for most aspects of plant and animal life in the soil, e.g. incorporation of nutrients into plant roots. Soil aggregation As the small soil particles pass through the earthworms' intestines, they are bound together with a mucus substance into larger masses of particles. This improves the structure of the soil, as well as incorporating the decomposed organic matter into these masses. These larger masses or aggregates are frequently referred to as 'castings'. Soil aeration By eating their way through the soils and producing larger aggregates. channels develop in the upper soil horizons, which permits the increased movement of air, specifically oxygen, into the soil. The presence of adequate oxygen in the upper soil layers is essential for the growth and development of all aerobic plants and animals. Infiltration of water into the soil The channelling and aggregate production by earthworms increases the ability of water to penetrate the soil surface into the upper layer. Infiltration is one of two important aspects of soil water movement. Percolation of water within the soil The second aspect is percolation, the movement of water within the soil. The activity of earthworms increases the ability of soil water to move down and throughout the soil horizons. The availability of soil water at the level of the plant roots is important for plant growth and development. Soil turnover Soil turnover is the amount of soil that passes through the body of an earthworm in a certain time period. Experiments in North America and Europe have measured this activity and found it to be mg of soil per day per worm. All habitat factors being equal, the range is primarily due to the varying sizes of different earthworm species, in that the amount of soil passing through an earthworm's digestive system per day represents approximately 20-30% of its live body weight. So why would anyone object to having earthworms in their soil and grass cover? Volumes have been written concerning earthworms and their casts on golf courses (Jefferson, 1958; Kirby and Baker, 1995; Backman et al., 2001; Bartlett et al., 2008; Potter et al., 2010; Redmond et al., 2014) to name a few. It is easy to see why golfers would object to surface casting by earthworms which would adversely affect the roll of the ball. A golf ball has a standard size of mm in diameter. The weight of a golf ball is grams and must not exceed this, as the heavier it is the less it is slowed down by air resistance. It is important to remember that not all earthworm species are responsible for surface casting. There are 256+ earthworm species in North America (Reynolds and Wetzel, 2008 and 2012), but the number of casting species reported from golf courses is restricted to about a dozen. Richmond et al. (2014) reported heavy casting on sand-based putting greens in Kentucky by Amynthas hupeiensis. This and other Asian exotic species have yet to be reported from Canada (Reynolds and Wetzel, 2012). These exotics are moving north and have been reported from New York (Reynolds, 2010; Rodríguez et al., 2012) and Vermont (Görres and Melnichuk, 2012; Reynolds, 2012). Very little has been reported concerning earthworms on lawn bowling greens. Since I turned in my golf equipment for a set of lawn bowls, and have been part of the lawn management committee at our local lawn bowling club (Heritage Greens Lawn Bowling Club, Kitchener) for several years, it was brought to my attention by our head greenskeeper that there has been a increase in earthworm activity on our

3 MEGADRILOGICA 71 greens this past year (2013), as well as on most lawn bowling greens at other clubs in our region. Unlike golf balls, lawn bowls are made of Melamine and come in a variety of sizes and weights. Melamine resin or melamine formaldehyde (also shortened to melamine; 1,3,5-Triazine-2,4,6-triamine; C 3 H 6 N 6 ) is a hard, thermosetting plastic material made from melamine and formaldehyde by polymerization (Table 1). Table 1. Lawn bowls size chart. Size Heavy (g) Extra Heavy (g) Additionally, lawn bowls are not spherical, but flattened on two sides and weighted or biased so that their path down the green is in a arc and not a straight line. From the size chart it can be seen that lawn bowls range from times heavier in weight than golf balls. On May 26 th, 2014 I contacted Lloyd Woods, a sports greens consultant, who previously worked with the members of the Ayr Lawn Bowling Club (10 Tannery Street, Ayr). This is a soil based green which has Lumbricus terrestris present. The following day (May 27 th ) I made a follow-up call to Abner Martin former greenskeeper at the New Hamburg Lawn Bowling Club (114 Union Street, New Hamburg) who verified the report of Betsey Gurtz that there are no worms at this club. The New Hamburg Lawn Bowling Club is a sand based bowling green built on natural sand. On May 28 th, I visited the Elmira Lawn Bowling Club (Mockingbird Drive, Elmira). This is a soil based green which is top dressed with sand. The earthworms present are Lumbricus terrestris, which are present along with many casting around the edges of the green in the mornings. My final club visit was to the Kitchener Lawn Bowling Club (169 Wentworth Avenue, Kitchener) on May 29 th. This is another soil based green where Lumbricus terrestris is evident early in the morning along with castings. Building of a Lawn Bowling Green (HGLBC) Since Heritage Greens is a sand based green, the following illustrates an abbreviated look at what is involved vis-à-vis a soil based green (Figures 1-7). MATERIALS AND METHODS Visitations were made to the lawn bowling clubs in Waterloo District where I had discussions with the greenskeepers in each club. I began with Heritage Greens Lawn Bowling Club (600 Heritage Drive, Kitchener). Because I am a member of this club, numerous visits and play dates occurred between May and September Earthworms were collected on September 9 th and 18 th. Heritage Greens have sand based playing fields. On October 1 st, I visited the Preston Lawn Bowling Club (427 Queenston Road, Cambridge). This club has a soil based playing field. Guelph Lawn Bowling Club (114 Gordon Street, Guelph) was visited on October 10 th. The Guelph then playing field is clay based with a metre root zone and with sand, gravel and soil on top of the clay. On October 11 th, I visited the Elora Rocks Lawn Bowling Club (74 David Street, Elora). This club's playing surface is 10 cm of sand and soil above sand. Due to the change in seasons, visitations to the remaining clubs took place in Fig. 1. Laying the gravel base of the greens. The top soil is removed and put to one side and a gravel base is put in place. Drainage pipes are laid down the sides of the greens and connected to drainage pipes in ditches across the greens. The drainage pipe ditches are filled with pea sand. The gravel base is then slightly "roofed" between the drainage pipe ditches so that water runs into the ditches.

4 72 Earthworms invade Lawn Bowling Greens Fig. 2. Rootzone, the material into which the grass is sewn, is spread over the top of the gravel base. Fig. 5. Gravel base is slightly roofed between drainage pipe ditches so that water runs into the ditches. Fig. 3. The plinth boards and backboards are set in place, the corners are first. Fig. 6. Final levelling of the greens prior to seeding. Considerable care is taken to insure that the greens are absolutely flat and smooth. Fig. 4. Drainage pipe ditches are filled with pea gravel. Fig. 7. The first grass after seeding. It takes several months before the grass begins to look like a bowling green (Woods, 2000).

5 MEGADRILOGICA 73 RESULTS The first sampling for earthworms occurred at the Heritage Greens Lawn Bowling Club in August and September The initial results were Aporrectodea rosea on September 9 th (1-0-0) 1 and September 18 th (1-0- 1) as well as Aporrectodea tuberculata on September 9 th ( 2-0-1) and September 18 th (0-0-5). These two species were collected, but not retained on numerous other occasions (Fig. 8). Fig, 8. An earthworm exiting the green during a midafternoon game at Heritage Greens Lawn Bowling Club. During my visit to the Preston Lawn Bowling Club on the evening of October 1 st, I was quite surprised by the tremendous number of Lumbricus terrestris (est. ~100s), out of their burrows and moving across this soil based green. This club suffers from a serious earthworm infestation. The greenskeeper informs me that each morning he needs to level the castings before the members can play. I took several specimens to confirm my initial field identification of this species. The same situation occurred the evening of October 10 th when I visited the Guelph Lawn Bowling Club, another soil based green. Earthworms collected on this visit were also Lumbricus terrestris, but the density of this species observed on this visit was much lower. A few samples were taken to confirm my initial field identification of this species. The next day at the Elora Rocks Lawn Bowling Club, a soil based green, Lumbricus terrestris were the earthworms on their greens. During the last week of May 2014, I visited and evaluated the earthworm situation at the remaining four lawn bowling clubs. The Ayr Lawn Bowling Club, Elmira Lawn Bowling Club and the Kitchener Lawn Bowling Club each have soil based greens, and each have Lumbricus terrestris infestations to various degrees. 1 represents the number of juveniles-aclitellate adults-clitellate adults Surprisingly, earthworm infestation of the sand-based greens at the New Hamburg Lawn Bowling Club has not yet been reported by the members. I cannot yet offer any reasons for their absence from these greens. DISCUSSION Notwithstanding that earthworms are generally beneficial for lawns and turf, it has long been the practice for golf courses to lease out their clubs to the worms pickers in the bait industry. This is profitable for the golf clubs, because of their large area and the fact that worm castings on the greens have a greater effect on the ball as it approaches the cup. Bowling greens are relatively small surfaces, which would not be suitable for the worm pickers. Secondly, the castings will have a lesser affect on the path of the bowl because of it size and weight. The castings of earthworms are of four types, two of which are found in the local bowling greens. The first is globular, consisting of coalescent round or flattened units, generally produced by the larger, anecic and endogeic species (e.g., Lumbricus terrestris and Aporrectodea longa). The second is granular, typically in the form of pellets, produced mainly by smaller epigeic, small endogeic, and some anecic species, e.g., Aporrectodea rosea and Ap. tuberculata (Lavelle, 1988). The casts from different earthworm species can have very different effects on soil structure. On lawn bowling greens, the castings are not left on the surface very long, as the greenskeepers generally remove the globular casts of Lumbricus terrestris each morning. In the case of granular casts of the species of Aporrectodea, they are so small and dispersed that they are destroyed during play by the members walking over them. The interesting aspect of the earthworms at Heritage Greens is that they appear on the surface during games in the middle of sunny afternoons. This club has greens, each with a deep sand base;worms can be found in the centre of the green after crawling through many metres of sand before surfacing. Lawn bowling greens are generally square with sides between metres. Therefore, when earthworms are found in the centre of the bowling green, they have crawled approximately 20 metres through sand before surfacing. The amounts of cast produced in different regions and habitats have been summarized in Edwards and Bohlen (2004). Most studies have been done in

6 74 Earthworms invade Lawn Bowling Greens field or forest locations and reported as tonnes/hectare, but I will convert these data to a theoretical bowling green (Table 1). The Heathland approximates a soil based bowling green and the Oakwood approximates a sand based bowling green. Table. 1. Estimated yearly cast production on a bowling green. Habitat g/bowling green/year Heathland (loam) Oakwood (sandy soil) Based on my observations at the Preston Lawn Bowling Club, the production of earthworm casts at that club may be higher because of the greater density of the earthworms compared to field conditions. In the case of Heritage Greens Lawn Bowling Club, I would expect the cast production associated with the greens would be less than likely are found in more natural conditions. These data are based on European habitats, as the earthworms on our greens are introduced European (exotic) species (Reynolds, 1977, 2014). A sand based bowling green is not the most suitable habitat for earthworms. Species like Aporrectodea rosea and Ap. tuberculata eat their way through soil obtaining their nutrient intake from the soil organic matter. The soil organic matter is usually produced by the litter deposited on the surface which gets incorporated into the soil. At Heritage Greens the verticutting 2 takes place weekly as a rule, with vertical cutting first, then the cut grass is raked and removed, followed by a horizontal cutting after which the grass is removed again. This leaves essentially no clippings to be incorporated as organic matter. A sand based bowling green is not a suitable habitat for earthworm according to the habitat requirements discussed by Reynolds (1973, 1994): there is no adequate and suitable food supply, no protection from ultra-violet wavelengths of sunlight, and some toxic chemicals (herbicides) are frequently present. On the positive side, there is aeration of the greens, suitable ph is present, as well as watering (sufficient moisture), but the water does not remain in the sand for long because of the drainage tiles, the porosity of the sand, and the low moisture holding capacity of the sand (a atmospheres). Thus, it was quite surprising that earthworms continue to be present on the greens. Since earthworms can t see and generally move in search of a favourable habitat, they inadvertently move into the green and keep moving in search of a suitable habitat. The question I was most frequently asked by the greenskeepers was, How do we get rid of these unwanted earthworms?. Although earthworms are generally bioaccumulators storing toxins in the chlorogogen cells (= primitive livers), there are some chemicals which are extremely toxic to earthworms. The following paragraph and Table 2 present some chemicals which are the most toxic to earthworms Table 2. Some Chemicals adversely affecting earthworms (considered extremely toxic). Chemical Trade Name(s) Chemical Class Use(s) Formula Aldicarb a Temik Carbamate Insecticide, Nematicide C 7 H 14 N 2 O 2 S Bendiocarb Ficam, Dycarb Carbamate Insecticide C 11 H 13 NO 4 Benomyl Benlate, Tersan Benzimidazole Systemic fungicide C 14 H 18 N 4 O 3 Carbaryl c Sevin Carbamate Insecticide C 12 H 11 NO 2 Chlordane b Chlordan Organochlorine (cyclodiene) Insecticide C 10 H 6 Cl 8 Chloroacetamide Organochlorine Herbicide, preservative ClCH 2 CONH 2 Chloropicrin Chlor-O-Pic Nitrochloroform Insecticide e CCl 3 NO 2 Endrin b Mendrin Organochlorine (cyclodiene) Insecticide, Nematicide C 12 H 8 Cl 6 O Heptachlor many Organochlorine (cyclodiene) Insecticide C 10 H 5 Cl 7 Pentachlorophenol d PCP Organochlorine Insecticide, preservative C 6 HCl 5 O Phorate Thimet Organophosphate Insecticide, Acaricide C 7 H 17 O 2 PS 3 3-Chlorophenol Phenol Organochlorine Industrial chemical C 6 H 6 ClOH a only to be used by an licenced applicator b banned in many countries c not available in Canada, widely used in USA d not available to the general public e broad spectrum antimicrobial, fungicide, herbicide, insecticide and nematicide 2 Verticutting, or vertical mowing, is the process of mechanically removing thatch build up in the greens. Thatch is the layer of dead biomass (e.g., stems and roots) between the soil and the green grass.

7 MEGADRILOGICA 75 A list of 193 chemicals known to affect earthworms is provided in Ernst (1995) and again in Edwards and Bohlen (2004); some of the most toxic to earthworms are presented in Table 2 (p. 74). Some chemicals have been subsequently banned in many countries, or must be applied by those applicators licenced to use them, but they may be available in neighbouring jurisdictions. Although this list is brief, it does contain the names of those 'extremely toxic' visà-vis those 'very toxic' or 'moderately toxic'. Acknowledgements I am grateful to Wilma M. Reynolds of the Oligochaetology Laboratory, Mark J. Wetzel of the Illinois Natural History Survey, Frederick W. Kutz formerly of the U.S. Environmental Protection Agency, and Lloyd Woods of Greens Maintenance and Construction for reviewing the manuscript, their comments and suggestions. I am indebted to the various greens-keepers, members and staff at the local lawn bowling clubs for their assistance: Ayr Lawn Bowling Club (Lloyd Woods), Elmira Lawn Bowling Club (Rob Brooks, Tony Gorman), Elora Rocks Lawn Bowling Club (Ian Burns), Guelph (Kase Kornelise), Heritage Greens Lawn Bowling Club (Bruce Krafcheck, Lloyd Woods), Kitchener Lawn Bowling Club (Bill Blake, Jack Kok), New Hamburg Lawn Bowling Club (Betsey Gudz, Abner Martin), and Preston Lawn Bowling Club (Richard Ballock). The author also wishes to thank Dr. Catalina C. de Mischis, Universidad Nacional de Córdoba and Dr. Jean-Marc Gagnon, Canadian Museum of Nature for the translation of the abstracts and key words. LITERATURE CITED Backman, P.A., E.D. Miltner, G.K. Stahnke and T.W. Cook Effects of cultural practices on earthworm casting on golf course fairways. Internat. Turfgrass Soc. Res. J. 9: 3-7. Bartlett, M.D., I.T. James, J.A. Harris and K. Ritz Earthworm community structure on five English golf courses. Appl. Soil Ecol. 39: Edwards, C.A. and P.J. Bohlen Biology and Ecology of Earthworms, 3 rd ed. London: Chapman and Hall, xii pp. Ernst, D The Farmer s Earthworm Handbook. Brookfield, WS: Lessiter Publications, 112 pp. Görres, J.H. and R.D.S. Melnichuk Asian invasive earthworms of genus Amynthas Kinberg in Vermont. Northwestern Nat. 19(2): Jefferson, R Studies on earthworms of turf. C. Earthworms and casting. J. Sports Turf Inst. 9: Kirby, E.C. and S.W. Baker Earthworm populations, casting and control in sports turf areas: a review. J. Sports Turf Res. Inst. 71: Lavelle, P Earthworms and the soil system. Biol. Fertil. Soils 6: Potter, D.A., C.T. Redmond, K.M. Meepagala and D.W. Williams Managing earthworm casts (Oligochaeta: Lumbricidae) in turfgrass using a natural byproduct of tea oil (Camellia sp.) Manufacture. Pest. Manag. Sci. 66: Redmond, C.T., A. Kesheimer and D.A. Potter Earthworm community composition, seasonal population structure, and casting activity on Kentucky golf courses. Appl. Soil Ecol. 75: Reynolds, J.W Earthworm (Annelida, Oligochaeta) Ecology and Systematics. Pp In Dindal, D. L. (ed.) Proc. First Microcommunities Conf. CONF , U.S.A.E.C., Natn. Tech. Inform. Serv., U.S. Dept. Com. Springfield, VA 22151, 285 pp. [paper in English; abstract none] Reynolds, J.W The earthworms (Lumbricidae and Sparganophilidae) of Ontario. Life Sci. Misc. Publ., Roy. Ont. Mus. xi pp. [book in English; abstract none] Reynolds, J.W Earthworms of the world. Global Biodiversity 4(1): [paper in English and French; abstracts in English and French] Reynolds, J.W The earthworms (Oligochaeta: Acanthodrilidae, Lumbricidae, Megascolecidae and Sparganophilidae) of northeastern United States, revisited. Megadrilogica 14(7): [paper in English; abstracts in English, French, Spanish, Italian]

8 76 Earthworms invade Lawn Bowling Greens Reynolds, J.W New earthworm (Oligochaeta: Megascolecidae) records from Vermont, USA. Megadrilogica 15(7): [paper in English; abstracts in English, French, Spanish, Filipino (= Tagalog)] Reynolds, J.W A Checklist by Counties of Earthworms (Oligochaeta: Lumbricidae, and Sparganophilidae) in Ontario, Canada. Megadrilogica 16: (in prep.). [paper in English; abstracts in English, French, Spanish] Reynolds, J.W. and M.J. Wetzel Terrestrial Oligochaeta (Annelida: Clitellata) in North America, including Mexico, Puerto Rico, Hawaii, and Bermuda. Megadrilogica 12(12): [English; abstracts in English, French, Spanish] Reynolds, J.W. and M.J. Wetzel Terrestrial Oligochaeta (Annelida: Clitellata) in North America, including Mexico, Puerto Rico, Hawaii, and Bermuda. III. Megadrilogica 15(8): [paper in English; abstracts in English, French, Spanish, Estonian] Rodríguez, A.R., R.S. Ostfeld, F. Keesing and J.W. Reynolds The earthworms (Oligochaeta: Lumbricidae and Megascolecidae) of Dutchess County, New York, USA. Megadrilogica 15(6): [paper in English; abstracts in English, French, Spanish] Woods, L Bowling Green Maintenance and Management, 2 nd edition. Ottawa: Lawn Bowls Canada, 64 pp. Web Site for the Journal Megadrilogica: Web Site for Nomenclatura Oligochaetologica Editio Secunda A catalogue of names, descriptions, and type specimens of the Oligochaeta: