Progress report for ONE19-345
To control Oriental beetle with mating disruption and B.t. alternatives to neonicotinoid insecticides. Improve blueberry plant health by reducing root feeding insect stress. Improve pollination by aiding in the improvement of pollinator health.
This project seeks to demonstrate how 2 alternative management strategies can be used in commercial blueberry production for Oriental beetle grub control. We will demonstrate the effectiveness of mating disruption used alone over 1 and 2 year periods. We will also demonstrate the effectiveness of the Bt, ‘beetleGONE!’ product, used alone and in combination with mating disruption treatments. This is a cooperative on-farm project, where growers will be making the applications, while we will be monitoring treatment performance, and reporting back to the participants and other commercial growers. Our objectives include the growers experiencing the results for 2 years, talking to other growers about the experience, and making presentations (Variety Farms) on their site. Successful completion of our objectives should result in further use of sustainable practices, and better control of Oriental beetle, resulting in lower grub populations and improved plant health. The project should benefit both farmers and beekeepers, since it will remove a major insecticide application that has negative effects on bees. Growers who presently don’t treat for Oriental beetle because of adverse bee and pollination issues, should change their practices and treat, knowing that their treatments will not affect pollination and improve plant health.
New Jersey is a leading producer of highbush blueberries, grown on 10,000 acres. Most of the production is on the sandy, porous soils in and around the Pinelands National Reserve, an ecologically sensitive area. Blueberries are a high value crop with plantings that average 1,450 plants per acre. NJ production ranks 6th in the US, and in 2017 was valued at $83.4 million (NJDA/NASS 2018). Good production practices can yield 12,000 to 14,000 lb/A, worth $18,000+/A. Full production can actually yield over $20,000/A, depending on market price and yield (Galinato and Gallardo, 2015). The Oriental beetle, Anomala orientalis, (OB) is the most abundant grub pest in New Jersey blueberries, and is considered by growers as one of the most important pests of blueberries in the state. Feeding damage caused by OB grubs can result in complete destruction of the root system, often killing entire sections of fields. Infested bushes show reduced vigor and support fewer berries, compared with healthy bushes.
Limited options are currently available to manage OB populations in blueberries. The neonicotinoid, imidacloprid is the only insecticide registered in blueberries for grub control. Imidacloprid requires precise application timing, has no efficacy against older larvae, is highly leachable, and may disrupt pollination. The difficulties with application timing have discouraged many growers from treating for OB. Applications are applied in early June during egg laying. This is the same period when blueberry bushes are closing in on the rows from fruit weight, making it difficult to use ground sprayers. Many growers do not treat for grubs because of the possible negative hold-over effects of imidacloprid residues in the flowers, and the perceived negative effects on pollination and fruit yield. As a neonicotinoid insecticide the negative effects of these compounds on bees have been well documented (Johnson, 2015; Williams et.al., 2015; Zhu et.al., 2017). Also, having a single control method raises resistance management concerns. Because blueberries are grown in an ecologically-sensitive area, it’s unlikely that additional soil applied insecticides will ever be registered for this use.
The blueberry IPM program monitors adult Oriental beetles (OB) with pheromone traps to help time insecticide applications. During the past 3 years our trap counts have increased compared to previous years. During our September soil fertility sampling, several grubs were found in the soil probe, suggesting that high populations were present in the fields. Therefore, we did a grub survey during the fall of 2018. We sampled roots from 6 bushes in each of 230 fields. Our results showed that OB grubs were present and feeding on roots in 64% of the samples. In some cases there were over 6-10 grubs per root system. This demonstrates the urgency of growers taking the steps to control this pest.
Recent advances in alternative controls shows promise in addressing the OB problem. Mating disruption dispensers (AgBio) gained EPA registration in 2012 (EPA, 2012) for hand-applied plastic dispensers. In 2013 a new strain of Bacillus thuringiensis subsp. Galleriae targeting several beetle species, attained an EPA label as ‘beetleGONE!’
We determined that 0.05 g of the oriental beetle pheromone, at 20 dispensers per acre was sufficient to provide effective oriental beetle mating disruption in blueberries (Rodriguez-Saona et.al.,2009). Recent work with a formulation of Bacillus thuringiensis subsp. Galleriae, has produced a new commercial insecticide effective for Scarab beetle grubs, ‘Phyllom beetleGONE!’(EPA, 2013). These products have been tested in small plots and are commercially available. Neither product is in wide-scale use at the present time. Mating disruption for Oriental beetle has been shown to be effective, while avoiding the difficulties of spray timing and the negative impacts of neonicotinoid use. The use of Bt Galleriae has been shown to be effective for Oriental beetle and similar species (Asana et.al, 2003), and its use in experimental plots in NJ appears promising (Rodriguez-Saona, 2014 unpubl.).
We have a number of years’ experience validating the efficacy of several forms of OB mating disruption (MD) dispensers (Rodriguez et.al., 2010; 2014). We know how the system works, how to place them and how many dispensers to use. This work has been supported by several EPA and IR-4 Biopesticide grants. Initial work in NJ with ‘Phyllom beetleGONE!’ showed promising results in 2014, but the data suggested that efficacy may be improved in a combination with another control such as mating disruption. Work in other states and crops has shown commercial efficacy on several Scarab species (Schwartau, IR-4, 2014).
Growers have overlooked the serious impact Oriental beetle causes. This is changing since populations have increased and grub infestations are now common. In fact, growers are asking us what other control options there are, besides the traditional imidacloprid soil sprays. Concurrent to OB population increases and resulting grub infestations, beekeepers are experiencing serious colony collapse associated with blueberry pollination services. Among other consequences, this is causing a degree of friction between beekeepers and blueberry growers, is resulting in hive loss for the beekeepers and increases in hive rental for blueberry growers. For a medium size blueberry farm of about 250 acres, the hive rental increase alone represents $10,000 to $15,000.
Therefore there are several aspects in the Oriental beetle problem and our approach that are new.
- Oriental beetle populations have increased over the last 3 years as shown by our adult pheromone trap records. Peak captures during the last 3 years have ranged from 10,000 to 15,000 beetles per trap/week, whereas previous year peak captures were 5,000-6,000 adults per trap.
- Most growers have neglected treating for Oriental beetles, given difficulties with application timing and bee toxicity issues.
- High adult populations have translated to widespread larval/grub infestations, which affect bush health and yield.
- New practices are available. Mating disruption needs to be demonstrated by the growers on a commercial scale, and a new Bt selection is ideally suited to be folded into an on-farm alternative control system.
Successful commercial use of these 2 practices will reduce OB populations without the problems associated with spray timing, and the negative effects of neonicotinoid use, as well as taking 1 more factor ‘off the table’ that has negatively affected bee health. The growers and we have collaboratively arrived at 3 demonstration sites that represent NJ blueberry production. Total acreage under the alternative practices will range from 12 to 250 acres per farm, and include large commercial production as well as small organic fields.
Asano, S. Yamashita, C, Lizuka, T, Takeuchi, K, Yamanaka, S, Cerf, D. and Yamamoto, T. 2003. A strain of Bacillus thuringiensis subsp. Galleriae containing a novel cry8 gene highly toxic to Anomala cuprea (Coleoptera: Scarabaeidae), BioControl 28:191-196.
Denson, C. 2018. Oriental beetle, still a hidden issue. Blueberry Open House. Hammonton, NJ. Rutgers
Cooperative Extension Annual Blueberry Grower Meeting, February 19, 2019
EPA, Office of Pesticide Programs. 2012. Reg No. 68253-1. https://www3.epa.gov/pesticides/chem_search/ppls/068253-00001-20120305.pdf
EPA Federal Register. 2013. Issuance of two experimental use permits. Document citation 78 FR 40737. Doc. No. 2013-16317.
Galinato, S.P., and Gallardo, R. K. 2015. 2015 Cost estimates of establishing and producing conventional highbush blueberries in western Washington. Washington State Univ. Extension. TB36.
Johnson, R. 2015. Honey Bee Toxicology. Annu. Rev. Entomol. 2015. 60:415-434. NJDA/NASS. 2018. NJDA 2018 annual report & agricultural statistics. www.nass.usda.gov.
OMAFRA. 2003. Mating disruption for management of insect pests. Ontario Ministry of Agriculture, Food and
Rodriguez-Saona, C., D.F. Polk, and J.D. Barry. 2009. Optimization of pheromone rates for effective mating disruption of oriental beetle (Coleoptera: Scarabaeidae) in commercial blueberries. J. Econ. Entomol. 102: 659-669.
Rodriguez-Saona, C.R., Polk, D., Holdcraft, R., and Koppenhöfer, A.M. 2014. Long-term evaluation of field-wide oriental beetle (Col., Scarabaeidae) mating disruption in blueberries using female-mimic pheromone lures. J. Appl. Entomol. 138: 120-132.
Rodriguez-Saona, 2014 unpubl. Preliminary trials with ‘beetleGONE!’ Schartau, K. 2014. IR-4 Food Use Workshop Presentation.
Williams, G.R., Troxler A, Retschnig, G, Roth, K, Yanez O, Shutler, D, Neumann, P, and Gauthier, L. 2015. Neonicotinoid pesticides severely affect honey bee queens. Nature Scientific Reports. 5: 14621, DOI:10.1038/srep14621.
Zhu, Y.C, Yao, J, Adamczyk, J, and Luttrell, R. 2017. Feeding toxicity and impact of imidacloprid formulation and mixtures with six representative pesticides at residue concentration on honey bee physiology (Apis mellifera). PLos One 12(6): e0178421, PMC5462352, PMID: 28591204. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5462352/
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- (Educator and Researcher)
We have completed the initial planning with 3 commercial blueberry growers. This project will last 2 years for the following reasons: 1) The Oriental beetle life cycle lasts for an entire year; 2) Grant funding for the 1st year would not start until well after OB management is finished for the 2019 season; and 3) Mating disruption practices show greater effectiveness in decreasing an insect population when done over multiple years, while lowering the population during treatment years (OMAFRA, 2003). Mating disruption also works better when used over large acreages or entire farms. This is why we are utilizing virtually entire farm sites for this work. Our farms range from 12 to 250 acres. See Figure 1-3 in “Demonstration Sites and Treatment Summary” attachment. Each site will be divided into 4 treatment areas, of unequal size. This will give us sufficient acreage for commercial demonstration and ease of grower management, and also 4 treatments and 3 replications for data analysis and publication. The treatment/demonstrations on each farm site will be:
- Mating disruption used alone.
- Mating disruption combined with 2 ground applications of ‘beetleGONE!’ Bt biological insecticide.
- 2 ground applications of ‘beetleGONE!’ insecticide used alone.
- Untreated control
Data Collection: Measuring Adult Activity - In each treatment plot we will place pheromone traps and weekly monitor adult Oriental beetles starting at first emergence the last week of May. We will place 2 Japanese beetle sex pheromone traps (Trecé, Adair, OK) baited with 0.3 μg of oriental beetle sex pheromone (Total 2 traps per plot, 4 plots, 3 replicates = 24 traps). These lures mimic female calling, and therefore create an accurate measurement of the adult male activity, responding to virgin females over a short distance, while not drawing males from outside the plot area. Traps will be placed in the plot centers at least 30 m apart and monitored weekly throughout the total adult emergence period. Trap records should reflect the relative populations within each treatment area. Adult trap capture is a measurement of MD effectiveness, producing very low trap counts. Trap counts in mating disruption plots are used to help assess the effectiveness of the mating disruption treatments, since the virgin female ‘mimic’ cannot be found by the males, traps captures should be almost shut down. However, lack of adult trap capture is only one measurement of treatment effectiveness. The actual damaging stage also has to be reduced. Therefore we will be sampling for both adult and larval populations in all treatment and check areas.
Measuring Larval/Grub populations – Soil texture in the commercial blueberry production areas in southern NJ is composed largely of acidic, medium to coarse textured sands, and accompanied with residual high organic content. Some are underlaid with thin clay layers. Therefore the water holding capacity of these soils is low. Blueberries have a shallow root system, which when combined with the soil characteristics, requires frequent irrigation. Therefor soils are often moist, easy to dig, and easily fall away from the roots. Oriental beetle oviposition starts in late May to early June and lasts through adult activity. By mid-July the first larvae are reaching the largest 3rd instar stage, and by late August to early September all larvae are 3rd instar. Larvae then overwinter in this stage around and just under the root system. Therefore we will measure larval infestation levels during November and December. We will use a 6 bush sample unit, using 3 sample sites per treatment or 3 samples per plot, 4 plots, 3 replicates = 36, 6 bush samples (216 per bush/soil and root exams). At each sample site 50% of the root system will be undercut on 1 side of the bush parallel to the row, and soil removed, examined and sieved for larvae/grubs See attachment labeled: “Oriental Beetle Larval/Grub Measurement – Site Location.” The root system remains intact, but the soil can be removed with minimal damage, since the bush is dormant by this time. After examination the soil is replaced and tamped down.
All adult activity and larval assessments will be each year (2020 and 2021). We will evaluate any differences in population density between the treatments and between years. Since OB has only 1 generation per year, larval density should decrease between years 1 and 2. Trap count levels or adult activity in the check plot and Bt alone treatments may decrease between the 2 years, but trap counts in any mating disruption plot should remain low during both years.
This work is designed as randomized complete block with 4 treatments outlined above, replicated on 3 different farms, with farms used as the block. Data consisting of numbers of adults per trap, and numbers of grubs per 6 plants will be analyzed using ANOVA, followed by LSD tests for mean differences. Data will be log transformed if needed. These are similar methods as used in previous work (Rodriguez-Saona et.al, 2009, 2014), and in our Oriental beetle grub survey done in 2018 (Denson, 2018).
Progress Fall 2019 through 2020 (As of January 2021):
Field Work -
We evaluated pretreatments Oriental beetle levels during 2019 and grub levels in the fall of 2019.
In spring of 2020, we met with the three collaborating growers to discuss how the layout of the MD tabs and the ‘beetleGone’ would proceed. At Farm A site we had the grower treat 17 acres of MD, Farm B - 30 acres, and Farm C - 180 acres. An example of plot layout is shown in figure 1-20 for farm C, where the green overlay is treated mating disruption and stars show sample sites.
Unfortunately, we had an issue with obtaining the ‘beetleGone’ product due to Covid-19, so those treatments were not applied in season 2020. Participating growers were asked how they felt about putting the MD tabs out, and all 3 growers learned the application system and applied the product during early May. At each site location we also placed an Oriental Beetle (OB) trap to monitor adult populations. Trap count numbers were assessed weekly starting the 1st week in June.
In the fall of 2020, we sampled for grub counts at all three locations. Samples were taken in all treatment areas where we assessed infestations during the fall of 2019. We GPS located each 6 bush sample site with the mobile app "Mapit" GIS to help in relocating the same sites during the following season.
March, April 2019 - Plan project with growers. Rutgers IPM and Growers
Year 1 Year 2
Initial pre-treatment assessment Nov., Dec. 2019 Nov., Dec. 2020
for larval densities. (Rutgers) (1st Yr Post Trt)
*Nov., Dec. 2021
(2nd Yr Post Trt)
Divide farm sites into March 2019 Done once March 2019
(Collaborative effort between
Rutgers and Growers)
Assess adult populations - May – August 2020 May – August 2021
Grower Meeting & Demonstrations May 2020 May 2021
Instructional workshop May 2020 May 2021
Grower Newsletters April – Aug, 2020 April – Aug, 2021
Apply Mating Disruption, May 2020 May 2021
Place Adult traps
Apply Bt biological insecticide Late May, and June, 2020 Late May, and June, 2021
(Rutgers and Growers)
Monitor and collect adult data Late May – August, 2020 Late May – August, 2021
Collect pesticide use records Sept. 2020-Nov. 2020 Sept. 2021-Nov. 2021
(Rutgers and Growers)
Data Analyses Jan. 2021 *Dec. 2021
Blueberry Open House Feb. 2021 *Feb. 2022
(Rutgers and a participating grower)
Fact Sheet --- *Jan.-Feb. 2022 *Activities marked may occur after grant funding expires, but will not require further grant funding to complete.
In order to achieve maximum effectiveness in this project it is necessary to take it for 2 full years. Given the biology of the pest, the pairing of pest biology and grant funding is not in good synchrony. We would like to start the pre-treatment grub survey during the Fall or 2019. This would schedule a 24 month funding cycle into late fall of 2021. This would also mean we would complete the final regularly scheduled winter meetings, as well as anything written based on 2 years information, after funding is completed. Therefore several items listed in this timetable are marked with an “*” to note this timing.
Progress to Date (As of February 2020)Table 1 Rpt 1
During the fall of 2019, we met with the three farmer collaborators to initiate grub counts. Six to eleven fields were sampled for grubs at each site to have an idea where we were going to place our 4 treatments. We examined 150 individual bushes by excavating and sieving the soil from 50% of the root area from each individual bush, then replacing and tamping down the soil. Our counts verified the significance of Oriental beetle grub populations, with an average of over 1.3 grubs per bush (Table 1). This was done at the start of dormancy in order to minimize the impact on the plants. Below is the data we collected from all three farm sites. Based on the data collected, we divided the farms sites into individual treatment areas and sampling locations for the 2020 and 2021 seasons. An example of sampling areas is shown below in the image of one of the farms sites comprising 200 acres, which 120 acres will be under mating disruption treatment and 15 acres under B.t. treatment Figure 1). A meeting was arranged with the supplier for the mating disruption dispensers to verify the supplies we need for the 2020 season.
Results 2020 (As of January 2021)-
Grub counts were compared in each plot across the 3 farm replicates. For year 1, there were no statistical differences between treatments. Some of the non-mating disruption data appears to be influenced by the fact that plots without mating disruption may have been influenced by the comparatively large acreage under mating disruption close to those plots. Two farms did show an increase in grub populations in the control areas and slight numerical decreases where mating disruption was used. It is common for the effects of mating disruption to become more pronounced after multiple years of treatment. Therefore, we look forward clearer results during 2021.
Extension Education - 2020
Participating grower consultations - Each of the 3 collaborating growers was visited once per week starting in mid-April through late August for a total of 18 visits for each grower or 54 total consultations. Due to the pandemic, actual grower communication was by phone and not in person.
Newsletter/Web Blog articles - Oriental beetle information was covered in 6 articles in 2 newsletter/blog posts. Total blog post "reads" for the season totaled 92,626 during the growing season.
Organized clientele/grower educational meetings - The 2020 educational meetings were conducted online in webinar format. Live webinars where this project was discussed included 140 participants, with 1,580 distributed recordings.
As of January 2021 - Collaborating growers accepted the new technology, organized their labor and made hand-applied applications of the mating disruption dispensers as needed. Final evaluations of actual grub populations will be done during the fall of 2021.
Education & Outreach Activities and Participation Summary
Cooperating farmers have met with us to help plan the locations for this work.