Recipient Organization
COLLEGE OF MICRONESIA
PO BOX 1179
KOLONIA POHNPEI,FM 96941
Performing Department
COLLEGE ADMINISTRATION
Non Technical Summary
Problem statement/situation statement/non-technical summaryCoconut Rhinoceros Beetle (CRB) is a large scarab beetle native to Southeast Asia and a damaging pest of palm species, most notably coconut palm (Cocos nucifera). CRB adults damage palms, particularly younger ones, by boring into the center of the crown, where they injure the young, growing tissues and feed on the sap. The damage can significantly reduce coconut production, and tree mortality can occur when CRB destroys the growing tip. Coconut palms are an important source of food and fiber, as well as part of many tropical islands' ecosystems, landscape and nursery industries, and iconic scenery. Coconuts are highly valued by residents and tourists as an important economic botanical in Palau and the region.A dire call for an emergency response for a new variant of rhinoceros beetle (CRB-G) that has invaded the Pacific Islands since 2007 is more critical than ever before. The fact that Pacific Island countries and territories have a diversity of native and introduced palm species and coconut being the pre-eminent amongst them as fundamental for food security, construction material and as an icon for tourism in the Pacific has made even more important for the region to curtail the damage caused by CRB-G. This highly damaging new variant has invaded Guam, Papua New Guinea, Hawaii, Palau and the Solomon Islands within the last 10 years and killed 70 - 80 percentage of palms, as it continues to spread. Throughout the region the presence of the CRB-Guam biotype has shown evidence of severe to catastrophic levels of damage (50 - 90 %) as compared to the CRB-Pacific biotype which, with virus biocontrol, only causes light to moderate damage (10 - 50%) in 'hot spots' with uncontrolled breeding sites.Palau has had moderate damage despite the presence of both biotypes and sever weather may result in a resurgence of the CRB because of increased breeding sites. It is resistant to the biocontrol virus and is literally killing palms as it advances its invasion. The beetle is invasive and has the potential of wiping out palms if proper control measures are not initiated, except in isolated resort environments where that have reduced damage by nearly 90%.Previous damage assessments show a slight rise in damage, which was more severe after sequential typhoons in 2012 and 2013 that increased breeding sites for the beetle. The damage was at its worst in 2015 with nearly every tree in Peleliu showing beetle damage and has affected the whole of Palau including the Northern and Southern Atolls. The beetle is also posing imminent invasion threats to other islands and countries with damage assessment of up to 75% of trees and therefore requires urgent attention. This project aims to address the issue of coconut damage in Palau, to prevent further damage and remediate areas that are most vulnerable to the damage, such as outer lying atolls, because food and hydration in drought is solely provided by coconuts. The protection methods such as trapping and prevention will be tested on islands to gauge effectiveness and concurrently, biocontrol will be assessed and released to gauge effectiveness.Why focus in Palau?Two biotypes of the CRB are in Palau: CRB-P & CRB-G. Damage Assessment Surveys were conducted on coconut trees in several locations in all of the 16 states in Palau in 2016, 2017 and 2018. These surveys were made to determine the amount of damage done by the beetles. Specialized traps were used along with manual searches through debris to collect and determine distribution of CRB-G as well as incidence of Oryctes Nudivirus (OrNV) infection. The results of the Damage Assessment Surveys show slow recovery/reduced damage in coconut tree fronds. Furthermore, analysis of biotype and viral detection show a very high rate of infection of all CRB with the nudivirus (CRB: 92%; CRB-G: 83%). The reduced tree damage and high rate of infection of the beetles, as well as visual assessments of CRB samples gut damage, lead to the preliminary conclusion that the OrNV in Palau CRB is virulent.Further assessment is necessary to try to correlate damage with biotypes and virus; as well as to identify and purify a virulent strain of OrNV that can be used for control for the Palau and the region.
Animal Health Component
50%
Research Effort Categories
Basic
25%
Applied
50%
Developmental
25%
Goals / Objectives
GoalControl current infestation of Coconut Rhinocerus Beetle in Palau and prevent further devastation of valued coconut crops through sanitation, trapping and focused effort on biological control that would be effective for the region.ObjectivesObjective 1. Standardize damage assessments in Palau with high throughput methodology; use this standardized method in Yap, Chuuk, Pohnpei, Kosrae and Marshall Islands with partners to have a regular assessment for CRB in place.Objective 2.ToDevelopasystematic response system to coconut rhinoceros beetle in Palau as a pilot project for the region; then extend to YapObjective 3.ToIdentify and evaluate endemic biocontrol agents (field collection dissections and growth chamber and viral assay)Objective 4. Outreach
Project Methods
MethodologyObjective1.Standardize damage assessments in Palau with high throughput methodology.Methods:Sites throughout Palau that have been previous identified will be assessed; CRB damages will be evaluated on up to 25 randomly selected coconut palm trees at each site. A scale of 0-4, developed by SPC (Secretariat of the Pacific Community), will be used for evaluations for top 4 fronds and entire tree: 0 = no damage, 1 = 1-29% removed (light), 2 = 30-49% removed (moderate), 3 = >50% removed (severe), 4 = dead palm.GIS locations of all assessment sites will be recorded, and a map will be produced as shown below from past surveys (MAP 1).Furthermore, Annotated drone or drive by video CRB damage surveys with online-based software (https://github.com/opencv/cvat) will be trialed for a more high throughput methods and compared to current damage assessment statistics.Objective 2.Todevelop a systematic response system to coconut rhinoceros beetle in Palau as a pilot project for the region.Methods:CRB trapping (netting mulching and solar and pheromone traps), breeding site sanitation and laboratory assessment.Netting/ mulchingNetting has been quite successful for private hotel, Palau Pacific Resort, reducing damage from an average of 2.5 to 0.2 (0-4 scale) over 1 year (unpublished assessment). We will test these methods at various study locations in Palau.Our target states are where trees show significant CRB damage, such as in Babeldaob (largest land mass in Palau), Koror (business and population center), including the uninhabited limestone Rock Islands, Kayangel the northern most atoll island state and the Southern most atolls in the Southwest.Net will be covering the crowns of coconut trees to capture the beetles before they can damage the coconut tree as well as at the base of trees to capture beetles crawling up the tree and samples will be collected and assessed.Traps with solar and pheromone luresTraps with Solar lights and Pheromone lures have been effective in trapping male and female beetles in the region (reference).These collections have been used to study biotype and OrNV infection.This method will be continued in Palauwith modification based on supplies available and will be checked regularly as well to have a standard collection method for comparison for the region.This is important for standardized review of effectiveness of virus distribution.Breeding site sanitationFor CRB trapping, possible breeding site around the area will be examined. If potential breeding sites, such as green waste and unidentified mulch are found, netting will be used to cover the mulch piles. This process will prevent the adult beetles in these breeding sites from flying out to the coconut trees as well as capturing samples and reviewing population subsets.Sites will be monitored and then sanitized per green waste management protocols that have already been developed at the Solid Waste Management site. Furthermore, larvae will be collected from sites for analysis of biotype and virus content.Objective 2.Identify and evaluate endemic biocontrol agents (field collection dissections and growth chamber and viral assay)Methods:Any samples collected will be dissected in the lab and DNA will be extracted from the legs or gut of each sample using DNeasy Blood and Tissue Kit by Qiagen, to undergo further DNA analyses to determine the biotype.To determine the distribution of CRB biotypes the DNA samples from the CRB samples collected undergo a polymerase chain reaction (PCR). We use a restricted fragment length polymorphism (RFLP) assay. This is a two-part assay where, first, we introduce the following primers C1-J-1718Oryctes (5'-GGAGGTTTCGGAAATTGACTTGTTCC-3') and C1-N-2191Oryctes (5'-CCAGGTAGAATTAAAATRTATACCTC-3') to amplify the CRB's cytochrome oxidase I (COI) gene. The expected band size after running the PCR sample through a gel electrophoresis is 523 base pairs as seen in Figure 1. The first lane is a negative control. Lanes labeled 1-6 are some samples that have gone through the PCR assay. The yellow "+" indicates a positive sample for CRB-P and the red "+" is a positive control for CRB-G. The ladder used for the visualization was the GeneRuler 100bp.The second part of the assay is to introduce the MSE1 restriction enzyme. After digestion we can better distinguish the CRB-P from CRB-G. The expected band size for CRB-G is 253. CRB-P sample will show banding at 181bp and 72bp.Lane 3, in Figure 2, is a visual representation of CRB-G after digestion.The third part of the study is to test for the presence of the CRB viral biological control, OrNV. Using the same samples collected, these samples undergo a PCR for OrNV detection where we introduce the following primers OrV15a (5'ATTACGTCGTAGAGGCAATC-3') and OrV15b (5'ATGATCGATTCGTCTATGG-3') to amplify the CRB's glycoprotein. The expected band size is 945bp as shown in Figure 3. For the visual representation we will use the GeneRuler 1kb as a comparative ladder.Identification is necessary to find populations of separated biotypes, but then after that infected beetles need to be assessed for virulence. OrNV infection appears to induce particular morphological deformations such as milky and swollen digestive system filled with organic matter in the abdomen of the CRB. Therefore, dissection of the all field-collected specimens will be performed to screen the pathogenic agents for CRB.If the specimen with symptom is discovered, we will isolate and propagate the pathogen for the further characterization.This will require Palau-based dissection and growth facilities, which will also be set up during the initial phase of the project development with partners from Hawaii, Japan and Germany and will have regular exchanges and monitoring.Furthermore, as it is evident that a viral strain exists in Palau that infects the resistant strain; we would create viral growth, replication chambers: with tandem viral purification, identification and storage preparation for distribution to the region.Screening the local biocontrol agents specifically for CRB-G is necessary to control the CRB population; and after development of Palau's biological control this method can be replicated foreach region, possibly in the form of a storage and infection facility; hence each station will be able to receive and store the virus as well as ability to infect CRB in their own country.Objective 4. OutreachMethods:1.School educationwill consist of working with the environmental and science clubs at the only local high school and the vocational college; members of these clubs as well as member of the newly established, local, PAIR Club summer program will develop awareness materials and presentations.The students will visit schools and deliver presentations as well as run field trips to show damage caused and how to reduce this damage.PAIR program will be the operations base for the laboratory and assessment team.2.Community outreachwill consist of working with: local companies or individuals that utilize coconuts for economic subsistence, such as producers of coconut oil and other coconut-based products; and resorts that use them as ornamentals.The work will consist of training techniques and taskforce development to deploy response system throughout the region and gauge its effectiveness.3.Public outreachwill consist of activities that include awareness campaign to all sectors in the government and community action groups through support from PIF partners; materials, training and assistance will be provided to assigned individuals with standard control/assessment techniques.Local media will be used for information dissemination and public awareness talk shows that will be question and answer format to allow for more public engagement.Furthermore, a website and social media will be established for cross-regional information dissemination and streamlined communication.