MANAGEMENT OF TURFGRASS AND LANDSCAPE PESTS IN HAWAII

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 1020615
• Project Start Date: Oct 1, 2019
• Project End Date: Sep 30, 2024
• Program Code: [(N/A)]- (N/A)

Recipient Organization
UNIV OF HAWAII
3190 MAILE WAY
HONOLULU,HI 96822

Performing Department
Plant & Environmental Protection Sciences

Non Technical Summary
Turf and landscape industry contributes significantly to Hawaii's economy. Due to biology, ecology, intensive management and disturbances, turfgrass and landscape systems oftentimes have different and specific pest issues compared to vegetable and cropping agricultural systems. In Hawaii, the year-round growing conditions are not only good for plants, but also good for a diverse range of turfgrass and landscape pests. Despite federal and state quarantine regulations, many new pest species become established in Hawaii every year. All these unique turf and landscape pest management challenges in Hawaii call for effective control strategies based on applied and basic research. Therefore, the overall goal of this integrated project is to provide effective turf and landscape pest management options to stakeholders in Hawaii, and on a broader sense, to turf and landscape industry in tropical regions of the world, through applied and basic research. Specifically, we will: 1) evaluate and identify strategies to manage key turf pests in Hawaii; 2) evaluate and identify strategies to manage key pests of landscape plants in Hawaii; and 3) disseminate information to stakeholders, and interested public. We will use some on-going and proposed research as examples to demonstrate our specific approaches. The information generated from this project will be disseminated to stakeholders and interested public via various venues, such as discussion, articles, presentations, "Field Day" demonstrations/workshops, and more. This integrated Hatch project focuses on the third CTAHR/USDA Program Area "Invasive Species Education and Management".

Animal Health Component

90%

Research Effort Categories

Basic

10%

Applied

90%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
211	2199	1130	35%
212	2199	1160	35%
213	2199	1140	30%

Knowledge Area
212 - Pathogens and Nematodes Affecting Plants; 211 - Insects, Mites, and Other Arthropods Affecting Plants; 213 - Weeds Affecting Plants;

Subject Of Investigation
2199 - Ornamentals and turf, general/other;

Field Of Science
1130 - Entomology and acarology; 1160 - Pathology; 1140 - Weed science;

Keywords

turfgrass

landscape plants

pest management

Goals / Objectives
The overall goal of this integrated project is to conduct research on turf and landscape pest management (mostly applied research, but also basic research to some extent), and based on which, to provide effective pest management options to stakeholders in Hawaii, and on a broader sense, to turf and landscape industry in tropical regions of the world. The specific objectives are:To evaluate and identify strategies to manage key turf pests in Hawaii;To evaluate and identify strategies to manage key pests of landscape plants in Hawaii;To disseminate information to stakeholders, and interested public.

Project Methods
Below we will use some on-going and proposed research as examples to demonstrate our specific approaches to the objectives mentioned above. Other turf and landscape pests may also be targeted following similar procedures. Since these specific objectives are not bound to each individual research, research and extension efforts are really continuous throughout the entire five years of this integrated project.Objective 1. To evaluate and identify strategies to manage key turf pests in HawaiiFrit fly (Oscinella frit) is a relatively new turfgrass insect pest in Hawaii. All species of turfgrass are susceptible (UC IPM, 2009). In Hawaii, bermudagrass is most susceptible to frit fly injury. Frit fly larvae tunnel in theturfgrass stems near the soil surface, causing the upper portion of the grass to turn yellow (chlorotic), then brown and die. Damage is most noticeable on golf course putting greens and fairways; although it can also occur on sports fields and lawns. Adult flies can become a nuisance to golfers because they can be attracted to light colored objects, such as golf balls, golf carts, caps, shirts and towels. Due to insufficient research, frit fly continues to be a management challenge for many golf courses in Hawaii. To address this issue, multiple field research trials have been and will be conducted on golf course(s) to evaluate efficacy of low-risk insecticides for frit fly control. These experiments will consist of multiple treatments and untreated control, arranged in randomized complete blocks with at least 4 replicated plots per treatment. Data on frit fly damage, turfgrass greenness, and overall turfgrass quality will be evaluated before and after each application of treatments.Take-all patch or take-all root rot, a root fungal disease of turfgrass, has been confirmed in Alabama, California, Florida, and Texas (Hagan et al., 2004), and is possibly present in other southern states. In 2015 and 2016, I confirmed this disease at multiple golf courses on Oahu, Big Island, and Maui. The causal pathogen is commonly considered to be Gaeumannomyces graminis var. graminis (Tani and Beard, 1997). It most occurs on stressed, closely mowed turfgrass, such as golf greens. In Hawaii, this disease most occurs on bermudagrass and seashore paspalum, two turfgrass species used for golf course greens. Take-all patch usually starts as yellow circular patches. Turf in patch area gradually turns brown. The roots darken and become thin and shortened, sometimes losing feeder roots and root hairs. When infestation is severe, a majority of the roots under the patch can become very dark color or even lost. In the case of Bermudagrass, this disease is especially active in winter when Bermudagrass becomes relatively inactive in Hawaii. To address this issue, multiple field research trials have been and will be conducted on golf courses to evaluate efficacy of fungicide programs for take-all patch control. These experiments will consist of multiple treatments and untreated control, arranged in randomized complete blocks with at least 4 replicated plots per treatment. Data on disease suppression, turfgrass greenness, and overall turfgrass quality will be evaluated before and after each application of treatments.Objective 2. To evaluate and identify strategies to manage key pests of landscape plants in HawaiiCoconut Rhinoceros Beetle (Oryctes rhinoceros, CRB) is a large scarab beetle native to southeast Asia and a damaging pest of palm species, most notably coconut palm (Cocos nucifera). In Hawaii, CRB was first confirmed at Joint Base Pearl Harbor-Hickam on Oahu in 2013. CRB has been identified by the United States Department of Agriculture-Animal & Plant Health Inspection Service (USDA-APHIS) as one of the most damaging invasive insect pests of coconut and other palm species whose introduction could result in significant economic losses to commercial coconut and palm nurseries, as well as Hawaii's residents and tourists who value palm trees for their aesthetic landscape value. My lab has been working on CRB control research since 2015, and we will continue and further expand from our on-going research efforts on chemical, biological, and cultural control of CRB on Oahu, with the overall goal to develop an Integrated Pest Management program against CRB readily applicable to Hawaii, and can be potentially extended to other tropical and subtropical regions of the world where CRB is present or has potential to invade. Specifically, we focus on low-risk systemic insecticides and certain biological control agents collected locally, including entomopathogenic fungi and nematodes, against CRB in lab assays and field research trials.The oriental flower beetle (OFB), Protaetia orientalis (Coleoptera: Scarabaeidae), is one of the recently established scarab beetles in Hawaii. It was introduced to Guam in 1970s and subsequently to Oahu in 2002, and since then spread to Big Island, Maui, Kauai, and possibly other neighbor islands. Adult OFB feed on flowers and/or fruits of agriculturally-important plants, and some landscape plants and crops, such as coconut palms, papaya, mango, corn, and more. It also damages flowers resulting in poor quality fruit and reduced fruit production. The adult female beetle lays eggs in the soil where the grubs develop and then pupate. The grubs are commonly found in soils underneath turfgrass and other landscape areas. Although not directly feeding on the roots of turfgrass and landscape plants, OFB larvae often cause physical damage to roots while moving and tunneling in soil, resulting in damaged/weakened turfgrass and landscape plants. Therefore, OFB is considered a pest to both the green industry (golf industry and landscape industry) and agricultural communities in Hawaii. To our best knowledge, there is no research-based data available on how to control this invasive pest in Hawaii, except one study indicated that a methyl eugenol fruit fly lure was attractive to OFB to some extent in Hawaii. To address this research gap, we recently started a 2-year research to identify effective yet environmental-friendly means to control this increasingly important pest. Laboratory and field efficacy trials will be conducted with potential bio-control agents (entomopathogenic nematodes, entomopathogenic fungi, etc.), low-risk systemic and contact insecticides, and cultural practices against this pest. This research-based IPM program against OFB is urgently needed by the green industry and agricultural communities here in Hawaii, which can be potentially adapted in other states in the U.S. should OFB disperse to other tropical and sub-tropical areas, such as California, Florida, and more.Objective 3. To disseminate information to stakeholders, and interested publicInformation generated will be integrated into educational and dissemination activities. The dissemination activities will be through verbal and written communications. Close interaction with stakeholders, industry groups will be one method of delivery. Public educational documents (information sheet, pamphlet/flyer, etc.), as well as extension/outreach articles in magazines/newsletters targeting turf and landscape industries will be produced. "Field day" demonstrations/workshops will be organized at various sites where research are conducted, to show research findings to the turf and green industries, related government agencies, and public at large in Hawaii. Research results will also be presented at industry annual meetings (such as Landscape Industry Council of Hawaii annual conference; Nutrien Ag Solutions annual seminar; etc.), to increase awareness and generate discussion with stakeholders and industry representatives. Communication through website and social media (facebook, twitter, blog, etc.) will also be made available.On multi-state scale, I will share project progress and results in the WERA-11 Western Regional Turfgrass Research group annual meetings.

Progress 10/01/19 to 09/30/20

Outputs
Target Audience:This project will directly benefit the turf and landscape industries of Hawaii. Target audiences include, but not limited to, turf and landscape professionals, golf course managers/superintendents, turf and landscape plant growers, home owners who have lawns, turf or landscape related organizations/associations, related government agencies, peer scientists, extension agents, chemical sales representatives, and interested public at large. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?During the period of 10/01/2019 to 09/30/2020, this integrated Hatch project provided the following key training and professional development opportunities. Seminar at 2019 Landscape Industry Council of Hawaii Annual Green Industry Conference: I team up with Landscape Industry Council of Hawaii (LICH) to deliver my state-wide extension seminars to stakeholders at LICH Annual Conference since I joined University of Hawaii at Manoa in 2013. The LICH Annual Green Industry Conference is Hawaii's premier green industry education event attended by approximately 250 people each year. Concurrent sessions focus on various aspects of landscape and turfgrass management and associated issues and offer Continuing Education Units (CEUs) for green professionals' certifications. In the 2019 conference (October 14, 2019), I provided my latest research updates on management of some key landscape and turfgrass pests in Hawaii, including coconut rhinoceros beetle, lobate lac scale, Ficus stem and leaf gall wasps, hala scale, and frit fly. My seminar was well received by approximately 50 turfgrass and landscape industry professionals, arborists, and UH-CTAHR extension agents. Presentation at 2019 Hawaii Agriculture Conference: Hawaii Agriculture Conference is hosted by the Agricultural Leadership Foundation of Hawaii (ALFH) every other year. The 2019 conference (October 15-16, 2019) brought together over 650 participants that represented a diverse group of agricultural stakeholders. I was invited to present at the invasive pests panel. In my presentation, I discussed important invasive species in Hawaii such as coconut rhinoceros beetle, lobate lac scale, Ficus stem and leaf gall wasps, and hala scale. My talk was well received by approximately 60 agricultural stakeholders. Presentation at 2020 CTAHR Invasive Pest Mini-Conference Series: I was invited to give a talk at 2020 CTAHR Invasive Pest Mini-Conference Series on August 20, 2020, providing my latest research updates on management of some important landscape and turfgrass pests in Hawaii, including coconut rhinoceros beetle, lobate lac scale, Ficus stem and leaf gall wasps, hala scale, oriental flower beetle, foliar nematode, plumeria rust, mini ring (a turfgrass fungal disease), take-all patch (turfgrass fungal disease), rover ant, frit fly, and Bermudagrass (suppression in seashore paspalum). My seminar was well received by approximately 30 CTAHR colleagues, state and federal scientists, pest management professionals, and more. Lectures at 2020 UH Master Gardener Programs: I was invited to offer lectures at 2020 UH Master Gardener Programs on Oahu and Kauai, both in May 2020. UH Master Gardener Program aims to provide the public with unbiased, research based information and sustainable management practices in tropical horticulture suitable for home gardens, local landscapes, urban environments, and the community. I tailored my 2.5-hour lecture for participants with a general interest in their lawn and yard management, and added to their knowledge of turfgrass by presenting common turfgrass species in Hawaii, key cultural practices, and lawn IPM. My presentations created animated and useful discussions among participants. How have the results been disseminated to communities of interest?In addition to the key training and professional development opportunities mentioned in the above section, the results of this Hatch project have also been disseminated in the following ways in the period of 10/01/2019 to 09/30/2020. Via oral or poster presentations at conferences and meetings: Cheng, Z. CTAHR's Turfgrass and Landscape Pest Management Program & IR-4 Program. 2019 CTAHR'sLegislative Tour. November 21, 2019. Honolulu, HI. Russo, M., Z. Cheng, K. Mitsuda, J. Li, and M. Kellar. Potential use of local strains ofentomopathogenicfungus to control the coconut rhinoceros beetle,Oryctesrhinoceros,on Oahu,Hawai'I (virtual poster). 2019 Annual Entomological Society of America (ESA) meeting. November 17-20, 2019. St. Louis, MO. Via exhibits/discussions at local public/community events: I organized an exhibit booth at 2020 CTAHR Day event on January 31, 2020. Three golf course superintendents worked with me at our exhibit. Over 200 public visitors learned turfgrass and golf industries in Hawaii when visiting my demonstration exhibit. Via multistate activities: Western Regional Turfgrass Research Group (WERA-011). Since February 2014, I have been the official representative for Hawaii for WERA-011. This is a committee of peer scientists from the western region involved in research, extension, and education activities related to turfgrass. The WERA-011 strives to foster exchange of information of current research and extension activities; and promote cooperative efforts among turf programs in the western region. I attended the 2020 WERA-011 meeting on June 22, 2020 via Zoom, and shared turfgrass research, extension, and education activities and effort in Hawaii. I then lead a sub-committee working on pest management components for the renewal of WERA-011 for the next 5 years. Via "Turf Column" in Landscape Industry Council of Hawaii's (LICH) professional magazine "Landscape Hawaii": I created in 2013, and am coordinating the "Turf Column" in LICH's professional magazine "Landscape Hawaii". This popular magazine has a readership of 20,450 (https://www.hawaiiscape.com/landscape-hawaii-magazine/) in Hawaii as well as on the U.S. mainland. I consider my "Turf Column" in the magazine an important "distance-based" extension vehicle to deliver knowledge and information to green industry professionals otherwise difficult to reach. In addition to writing articles myself for this "Turf Column", I also invited writers such as golf course managers, sod farm owners, and UH scientists who work on some aspects of turfgrass. Via Extension/Outreach/Popular articles: Cheng, Z. 2020. Research update on management of turfgrass fungal disease leaf and sheath spot in Hawaii. Landscape Hawaii, July/August 2020: 18-19. Cheng, Z. 2020. The care and feeding of your lawn. CTAHR News, June 22, 2020. https://cms.ctahr.hawaii.edu/NewsLetter/ArtMID/52574/ArticleID/1726/The-Care-and-Feeding-of-Your-Lawn What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Below I provide a brief summary of key research activities, results, and outcomes/accomplishments for the report period of 10/01/2019 to 09/30/2020. Control of Chinese Banyan Stem and Leaf Gall Wasps: A new species of fig gall wasp was discovered in Hawaii in 2012. This wasp attacks Chinese banyan (Ficus microcarpa), a common landscape tree species in Hawaii and other tropical regions of the world. It appears to be in the same family and genus (Agaonidae, Josephiella spp.) as the Chinese banyan leaf gall wasp (Josephiella microcarpae). We conducted a series of experiments against these two pests in our previous research, and concluded that emamectin benzoate delivered via trunk injection resulted in the best control efficacy, and one treatment can protect trees for about 1.5 years. In this reporting period, we continued to experiment new control strategies against both stem- and leaf- gall wasps, including 3 treatments (trunk injection of Dinocide, Dinocide Hp, and Abacide 2) and the untreated control. Sixteen Chinese banyans were included, and there were 4 trees under each of the 3 treatments and the untreated control. Monthly data on gall wasp infestations were collected from these trees. This was a one-year experiment from January to December 2020. We are currently analyzing the entire 12-months data collected. This research is related to objectives 2 and 3 of this Hatch project. Control of Lobate Lac Scale on Ficus species: Lobate lac scale (LLS; Paratachardina pseudolobata) was first discovered onOahu on weeping banyan (Ficus benjamina) in 2012. The major effects on host plants are dieback of twigs and branches, thinning of foliage, anddeath of the entire plant in some species. We confirmed LLS infested many plant species on Oahu, among which Ficus species areheavily infested. We conducted a series of experiments against LLS on Ficus in our previous research, and concluded that imidacloprid delivered via trunk injection was very effective in managing LLS, both curatively and preventively, and one treatment can protect trees for at least 2 years. In this reporting period, we continued to experiment new control strategies against LLS, including 3 treatments (trunk injection of Dinocide, Dinocide Hp, and Imicide) and the untreated control. Sixteen banyans were included, and there were 4 trees under each of the 3 treatments and the untreated control. Monthly data on LLS infestations were collected from these trees. This was a one-year experiment from January to December 2020. We are currently analyzing the entire 12-months data collected. This project is related to objectives 2 and 3 of this Hatch project. Coconut Rhinoceros Beetle Survey and Control: Together with Dr. Michael Melzer (PEPS), we are coordinating UH's effort on survey and control of the coconut rhinoceros beetle (CRB; Oryctes rhinoceros), a major new invasive species confirmed on Oahu since 2013, attacking coconut and other palms. This project manages the survey team to continue deploying and monitoring CRB traps across Oahu. We also work on chemical, cultural and biological control of CRB larvae and adults. My CRB research focuses on systemic insecticides and selected biological control agents (entomopathogenic nematodes and fungi). Our lab assays so far indicated that imidacloprid, acephate, dinotefuran, and abamectin had good efficacy against CRB adults. Therefore these 4 systemic insecticides are being tested in 2 concurrent field trials (curative trial and preventive trial, December 2019 to present), in which 70 coconut palm trees are included and monthly CRB damages are being measured. Lab tests of additional low-risk insecticides will continue. In addition, we have collected multiple strains of entomopathogenic nematodes and fungi from Oahu and are currently testing these against CRB larvae in lab assays. So far, we have identified multiple Metarhizium strains that are highly effective (> 60% mortality) against CRB larvae. This research is related to objectives 2 and 3 of this Hatch project. Control of Oriental Flower Beetle: The oriental flower beetle (OFB), Protaetia orientalis (Coleoptera: Scarabaeidae) is one of the recently established scarab beetles in Hawaii. It was introduced to Guam in 1970s and then to Oahu in 2002. The adult beetle feeds on pollen and nectar, ferments sap, and damages fruit of various edible and landscape plants. Although not directly feeding on roots of turfgrass and landscape plants, OFB larvae oftentimes cause physical damages to roots while moving and tunneling in soil, resulting in damaged/weakened turfgrass and/or landscape plants. The overall goal of this research is to identify effective low-risk insecticides and biological control agents against OFB. In this reporting period, we focused on testing low-risk insecticides. Our multiple lab assays suggested that acephate was very effective against OFB larvae, and dinotefuran also showed some effects against OFB larvae in lab assay. In addition, we have collected multiple strains of entomopathogenic nematodes and fungi from Oahu and are currently testing these against OFB larvae in lab assays. This research is related to objectives 1, 2, and 3 of this Hatch project. These research projects and directly related seminars at various occasions and discussion with stakeholders at multiple meetings have helped green industry professionals state-wide to understand more about important turf and landscape pests in Hawaii, and have provided with them viable control options. For examples, Punchbowl Cemetery, in collaboration with ArborJet, treated over 50 of their Chinese banyan trees based on my research recommendation. City and County of Honolulu, University of Hawaii Landscape Services, East-West Center, Moanalua Gardens, and several golf courses also treated hundreds of banyan trees to protect them from Ficus stem and leaf gall wasps and lobate lac scale using the methods I identified and recommended. Some local landscape professionals and arborists continue using the methods I recommended to control Ficus stem and leaf gall wasps and lobate lac scale on Chinese banyans and/or weeping banyans for their customers. Treating these trees infested by pests rather than cutting these trees down clearly has both economic and environmental impacts. Economically, treating these trees typically costs less than cutting them down and re-planting new trees. Environmentally, preserving these decades-old landscape trees provides benefits to soil erosion control and contributes to carbon sequestration in urban forestry.

Publications

• Type: Journal Articles Status: Published Year Published: 2020 Citation: Lindsey, A.J., DeFrank, J., and Cheng, Z. 2020. Bermudagrass suppression and goosegrass control in seashore paspalum turf. Journal of Applied Horticulture, 22(2): 92-96.
• Type: Journal Articles Status: Published Year Published: 2020 Citation: Waisen, P., Cheng, Z., Sipes, B.S., DeFrank, J., Marahatta, S.P., and Wang, K.-H. 2020. Effects of biofumigant crop termination methods on suppression of plant-parasitic nematodes. Applied Soil Ecology, 154, Article 103595.
• Type: Journal Articles Status: Published Year Published: 2020 Citation: Manandhar, M., Li, J., and Cheng, Z. 2020. Survey of entomopathogenic nematodes in various landscape systems on Oahu, Hawaii, and their pathogenicity against coconut rhinoceros beetle (Coleoptera: Scarabaeidae). Nematropica, 50(1): 36-44.
• Type: Other Status: Published Year Published: 2020 Citation: Cheng, Z. 2020. Research update on management of turfgrass fungal disease leaf and sheath spot in Hawaii. Landscape Hawaii, July/August 2020: 18-19.
• Type: Other Status: Published Year Published: 2020 Citation: Cheng, Z. 2020. The care and feeding of your lawn. CTAHR News, June 22, 2020. https://cms.ctahr.hawaii.edu/NewsLetter/ArtMID/52574/ArticleID/1726/The-Care-and-Feeding-of-Your-Lawn
• Type: Theses/Dissertations Status: Published Year Published: 2019 Citation: Russo, M. 2019. Potential biological control of the coconut rhinoceros beetle on Oahu, Hawaii. M.S. Thesis, University of Hawaii at Manoa. Major advisor: Zhiqiang Cheng.
• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Russo, M., Cheng, Z., Mitsuda, K., Li, J., and Kellar, M. 2019. Potential use of local strains of entomopathogenic fungus to control the coconut rhinoceros beetle, Oryctes rhinoceros, on Oahu, HawaiI (virtual poster). 2019 Annual Entomological Society of America (ESA) meeting. November 17-20, 2019. St. Louis, MO.