Mating disruption for the management of oriental beetle in ornamental nurseries: A research and extension effort

Final Report for LNE07-253

Project Type: Research and Education
Funds awarded in 2007: $106,876.00
Projected End Date: 12/31/2009
Region: Northeast
State: New Jersey
Project Leader:
Dr. James Lashomb
Rutgers University
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Project Information

Summary:

We conclusivly demonstrated that pheromone based mating disruption prevents mating of oriental beetles both of virgin and field reared beetles. However delayed licensing of the pheromone by the EPA precludes determining economic benefits. Also the pheromone does not impede mating in already infested pots in commercial nurseries. This makes wide scale adoption difficult. We are proposing its use as a preventative in new plantings which in itself could be very effective for the product cycle of the nursery.

Introduction:

The oriental beetle, Anomala orientalis (Waterhouse), is a major pest of nurseries in New Jersey. The sex pheromone of oriental beetle has been identified as a 9:1 blend of (Z)- and (E)-7-tetradecen-2-one (Zhang et al. 1994). Sex pheromone-mediated mate acquisition and copulation was found to occur at or near soil surface, shortly after emergence, close to the emergence site (Facundo et al. 1999). Previous studies evaluated the feasibility of microencapsulated sprayable formulations of (Z)- and (E)-7-tetradecen-2-one (Polavarapu et al. 2002). Trap captures in blueberry plots treated with the pheromone formulation were reduced by over 90% compared to untreated controls. Mating rates were also lower in treated plots compared to untreated plots. The sprayable formulation of the oriental beetle pheromone, being a ketone, does not qualify for EPA tolerance exemptions on food crops unlike other arthropod pheromones containing acetate, alcohol, and aldehyde moieties. An alternative formulation is the use of point-source dispensers, which are granted tolerance exemption for use on food crops. Sciarappa et al. (2005) evaluated mating disruption for oriental beetle using 20-30 ChemTica dispensers/acre containing 1g of (Z)-7-tetradecen-2-one per dispenser. It is imperative, however, to determine the minimal effective rate/acre because the cost of the active ingredient pheromone is close to $6,000/kg. The objective of this study was therefore to evaluate the more “economically-beneficial” and effective pheromone rate for oriental beetle mating disruption. For a better understanding the basic behavioral characteristic of the adult beetle related to the pheromone treatment, we studied the beetle dispersal capabilities. We also determined the host plat susceptibility to the oriental beetle.

Performance Target:

(1) At least 400 nurserymen (NJ and NY combined) will learn about the use of mating disruption to manage oriental beetle larvae. Duration: 3 months, Fall 2007,08, 09; and 3 months Summer 2008, 09, 10.

(2) 30 nurserymen will accept to fill out a survey on their white grub management practices. Duration: 3 months, Winter 2008.

(3) 25 nurserymen will agree to participate in a scouting program for oriental beetle and install pheromone dispensers on a portion of their farm for mating disruption purpose. Duration: 4 months, summer 2008.

(4) 22 nurserymen will participate in the scouting program and install pheromone dispensers on a portion of their farm for mating disruption purpose. Results from research will be presented during the spring. Technical assistance will be provided to install the dispensers. Duration: 6 months, spring/summer 2009.

(5) 20 nurserymen will participate in the scouting program and install pheromone dispensers on their farm for mating disruption purpose. Results from research will be presented during the spring. Duration: 6 months, spring/summer 2010.

PERFORMANCE TARGET
Of the 400 nurserymen were educated on mating disruption, at least 18 will adopt this technology by the end of the project. In so doing, participants will reduce their insecticide use.

Over the course of the project I gave talks at the annual SJ Nurseyrmens meeting as well as at least two night meetings held on farms. Summed up The number was closer to 250 growers that I talked to.

Of the 20-odd growers who filled out the form none were suitable for analysis. With that in mind I tried Survey Monkey for distributing the questionare. The rationale was they would respond from the privacy of their office. Again no usable results. Of the growers I spoke with privately they were enthusiastic about the prospects but deployment on the farm remained an issue.

For Objectives 3-5 we were limited by acreage used in the EPA permit but where we were able we enlisted grower participation in the dispruption phase. The Final Milestone: Due to the pheromone not being yet commercially available no grwers are emplying this technology. Another major deterrent to adoption is how to actuall use the disruption on a whole farm basis. I am still presenting the results to growers and am slated for another talk in October 2011 in Cumberland County NJ.

Cooperators

Click linked name(s) to expand
  • James Eaves
  • Valerie Fournier
  • Dan Gilrein
  • James Johnson
  • Albrecht Koppenhöfer
  • Jan Meneley
  • Robert Schaumloeffel

Research

Materials and methods:

1) Test the efficacy of different rates of the oriental beetle sex pheromone with ChemTica bubble dispenser in commercial nurseries.

The experiment was conducted in commercial nursery farms in New Jersey during in 2008-2010 to evaluate the efficacy of ChemTica pheromone point-source dispensers containing the major component (Z)-7-tetradecen-2-one for oriental beetle mating disruption.

In 2008, treatments were replicated in four different nursery farms: Hidden Lake Nursery, Cream Ridge; Carl Mehaffey Nursery, Bridgeton; County Line Nurseries, Bridgeton; Halka Nurseries, Bridgeton, New Jersey (1 farm = 1 replicate) and each treatment within farm (plot) was at least 100 x 100m (2.5 acres). Pheromone dispensers (AgBio Inc., 9915 Raleight St., Westminster, CO 80031. 303-469-9221, www.agbio-inc.com) were placed in an evenly-spaced grid in nursery on 13 June, 2008 at two different rates of 0.5 gram and 1.0 gram active ingredient per acre (Table 1).

In 2009 and 2010, only one pheromone rate (1.0 gram of active ingredient per acre) was used for the mating disruption study. In 2009, mating disruption treatment was conducted at Fruit and Ornamental Research Extension Center, Cream Ridge, New Jersey. Twenty dispensers with 50 mg pheromone per acre a total of 40 dispensers per plot were placed on June 17, 2009. In 2010, the study was repeated on June 21, 2010 in Fruit and Ornamental Research Extension Center, Cream Ridge, New Jersey and Overdevest Nurseries, Bridgeton, New Jersey.

Three Japanese beetle sex pheromone traps baited with 30 g of oriental beetle sex pheromone were placed in each plot in first week of June each year prior to placing dispensers to obtain number of beetles before treatment and monitored weekly to determine adult male populations.

Mating rates were assessed in each plot by placing screened cylinders containing a virgin female. Virgin females were obtained by collecting larvae from infested turf grass and rearing them to adults in lab condition with the similar temperature as they were in the field. Cylinder cages have been designed to allow males entering but preventing males and females from exiting. Individual virgin females were placed inside each cage. A total of 280 virgin females were placed in plots 4 times over a 2-week period: at the end of June, and 1st-2nd week in July, 2008. These cages were placed in plots for 3 nights and then retrieved to determine male presence. Retrieved females were placed in 30 ml rearing cups with moist sand and allowed to lay eggs to determine the female mating success. In 2009, 306 virgin females were placed in the cylinder cages individually in pheromone treated and control plots between June 22 – July 27, 2009. Sixty virgin females were placed between July 6 – July 23, 2010.

In 2009, 10 oriental beetle larvae were placed on each azalea plant (pot) during May 18-30, 2009 to monitor the impact of the pheromone treatment on beetle mating disruption and reproduction. Fifty of those plants were evenly distributed in each of the 2 acre treatment plots and were checked for grub numbers of next generation on Sept 20, 2009. In 2010, five oriental beetle larvae were placed on each azalea plant (pot) on May 27, 2010 and plants were checked during Sept. 13-17, 2010.

2) Adult dispersal behavior determination
Black light trap: Oriental beetle adult flight behavior was monitored by 2 light traps set up at Hort Farm II, New Brunswick, New Jersey during June 10 – July 30, 2008. Traps were visited daily to record the numbers of male and female oriental beetle adults.

Male marker-recapture: A marker-recapture experiment was conducted at the Rutgers Turf Farm, Adelphia, New Jersey to determine the distance male oriental beetle travel in response to different pheromone rates and/or sources. Adult males fresh were collected from 30g pheromone traps on the day of marker releasing. One hundred male oriental beetle adults were marked with gloss enamel Testors; paint for each releasing treatment plan with 5 distances and 4 pheromone types (Table 2). Individual virgin females were placed in a mesh cage that was attached to the beetle trap as regular pheromone lure. Marker-recapture treatments were repeated 3 times on July 1, July 2, and July 3, 2008. Marked male beetles were released in the late afternoon and collection traps were empted next afternoon for a 24 hours collection.
3) Susceptibility of various ornamental plants to oriental beetle.
Experiment was conducted at Cream Ridge, New Jersey. Oriental beetle larvae were inoculated in the 10 gallon pot-in-pot plants on September 20 and 21, 2008 to test the host plant susceptibility in 5 host plant species. Buxus (Boxwood), Rhododendron obtusum ‘Hino Crimson’ (Hino Crimson Azalea), Ilex (Japanese Holly), Thuja (Arborvitae), and Rhododendron. Each plant was inoculated with 0, 20, or 40 oriental beetle larvae. Six plants per treatment and repeated once. Plant performance of the infested plants was assessed susceptibility in May 2009 with parameters of height, above and below ground fresh biomass (weight), dieback percentage, and discoloration.

Research results and discussion:

1) Test the efficacy of different rates of the oriental beetle sex pheromone with ChemTica bubble dispenser in commercial nurseries.

Pheromone efficacy study was conducted in 4 nurseries in New Jersey. Pheromone dispensers were deployed on June 13, 2008 after empting the pheromone traps for pre-treatment count. As shown in Table 3 and Fig 1-4, male oriental beetle captures among various treatment plots were not significantly different prior to placement of disrupters. Post-treatment trap captures were significantly lower in plots treated with pheromone dispensers compared to trap captures in untreated control plots. There were very few male adults collected in the pheromone traps with either 0.5 gram per acre or 1.0 gram per acre comparing hundreds or even thousand male oriental beetle catches in the control plots (Fig 1-4). Only exception was observed in Halka nursery where 0.5 gram of pheromone dispenser deployment still left some males trapped in the collection traps (Fig. 3). This indicated that 0.5 – 1.0 gram per acre of pheromone deployment can almost completely confuse males in searching for females. Males were not able to locate traps with 30 g pheromone in the treated plots. There is no significant difference between 0.5 gram and 1.0 gram of active pheromone ingredient on adult male catches.

For the year 2009 and 2010, similar trends were observed for the adult male beetle pheromone trap catches as that in 2008 (Fig 5, 6, 7). Few male beetles were caught from pheromone treated plots in Cream Ridge in both 2009 and 2010, as well as Overdevest in 2010 after the dispenser deployments (Fig 5, 6, 7).

Pheromone mating disruption efficiency was also measured by placing virgin females in the plots for 3 days to determine if the males can discover the virgin females when provided a treatment. Virgin female adults attracted many more males in the field where no pheromone dispensers deployed (control plots) comparing those plots with pheromone dispensers (0.5 gram/acre or 1.0 gram/acre) in all four nurseries in 2008. By doubling the pheromone dispensing rate from 0.5 gram per acre to 1.0 gram per acre, about twice as many males lost the orientation in the high dose treatment field (1.0 gram/acre) (Table 4) (Fig. 8). Similar trend was observed in 2009 and 2010 when only 1.0 gram of active pheromone ingredient was used comparing to none pheromone control. In control fields, one virgin female attracted as many as 25 males in 2009 (Fig. 9) with an average of 0.35 males per virgin female in 2010 (Fig. 10). Virgin females attracted almost no males in the pheromone treated fields (Fig. 9, 10).

However, the mating disruption efficiency was not consistent to the number of male adults interrupted when measured by average numbers of eggs produced by individual females. Females from control plots produced more eggs in Hidden Lake and Halka nurseries comparing to the pheromone treated plots, but not in the County Line and Carl Mehaffey nurseries (Table 5) (Fig. 11). The fecundity may be a function of many factors rather than just availability of males. A minimum number of males may be enough for a successful mating required by egg production. This may explain reduction of males did not result in a low egg production by females placed in the field.

2) Adult dispersal behavior determination
Black light trap: Oriental beetle adult disperse flight behavior was monitored by 2 black light traps at Rutgers Hortfarm II, New Brunswick, New Jersey during June 10 – July 30, 2008. As shown in Figure 14, both male and female adults fly during the trap season. However, number of females caught in the light trap was much less than males. Adult oriental beetle peaked in the last week of June (Fig. 14) in central New Jersey, which was similar to the peak monitored by pheromone traps (Fig 1-4).

Marker-recapture: A marker-recapture experiment was conducted at Rutgers Turf Farm, Adelphia, New Jersey to determine the male oriental beetle response distance to different pheromone concentrations of each lure at 10 g, 30 g, 2 mg, and virgin female as standard control. Male adults can detect female pheromone from 200 feet when the lure has more than 10 g pheromone. Males can detect live virgin female from 100 feet. The efficient detect distance depends on pheromone concentration placed in the trap (Table 6) (Fig 15-18).
3) Determine the susceptibility of various ornamental plants to oriental beetle.

Host plant species susceptibility was determined by plant mortality both above ground and root damage. Host plant above ground mortality % varied significantly between plant species (F4, 179 = 15.03, P = 0.0001). Average above ground mortality was 33.75% for Pieris and 26.06% for Ilex. While Arborvitae (4.17%), Azalea (0%), Boxwood (0%) showed limited above ground damage. No significant difference was detected between oriental beetle larvae density (0, 20, 40 grubs per plant) on the above ground plant mortality (F2,179 = 1.51, P = 0.2248) (Fig. 19).

Host plant root mortality varied significantly between host plant species and OB grub densities (F4, 179 = 7.33, P < 0.0001 for host plant species; F2,179 = 12.93, P < 0.0001 for grub density). Root damages were significantly higher in Pieris (37.78%), Ilex (35.97%), and Azalea (32.36%) than in Arbovitae (20.28%) and Boxwood (14.17%). The average root damage % (33.58-34.92%) was significantly higher when with 20 or 40 grubs per plant than control (15.83%) plant without any grubs inoculated (Fig. 20).

4) Extension
Attached is a copy of one of the surveys we attempted with the growers. Over the course of the project we gave talks at the annual South New Jersey Nurseyrmens meeting as well as at least two night meetings held on farms. Summed up, the number was closer to 250 growers that I talked to.

Of the 20 odd growers who filled out the form none were suitable for analysis. With that in mind I tried Survey Monkey for distributing the questionare. The rationale was they would respond from the privacy of their office. Again no usable results. Of the growers I spoke with privately they were enthusiastic about the prospects but deployment on the farm remained an issue.

For Objectives 3-5 we were limited by acreage used in the EPA permit but where we were able we enlisted grower participation in the dispruption phase. The Final Milestone: Due to the pheromone not being yet commercially available no growers are emplying this technology. Another major deterrent to adoption is how to actuall use the disruption on a whole farm basis. I am still presenting the results to growers and am slated for another talk in October 2011 in Cumberland County NJ.

Participation Summary

Education

Educational approach:

We have presented these results to growers at least 5 times at night meetings and annual conferences like the South Jersey Nurserymen meeting. We have attempted to survey through Surveymonkey with limited success

Additional Project Outcomes

Project outcomes:

Impacts of Results/Outcomes

The growers still remain interested in this technology, but since there is no label the ultimate adoption is questionable.

Economic Analysis

The pheromone is still not approved by the EPA so production costs or for sale values can not be determined. We cannnot determine the cost savings without knowing the cost of application.

Farmer Adoption

Adoption is still up ion the air due the long delay in EPA approval. We also encountered a stumbling block in that the pheromone did not prevent mating in pots already infested by the beetle. That not withstanding we are prepared to recommend that growers surround targeted houses for new plantings woth pheromone to prevent inoculation. That is if they have an infestation insecticides would be the curative and pheromones would be the preventative.

Assessment of Project Approach and Areas of Further Study:

Areas needing additional study

Dispersal behaviour by females is still a major unknown. It appearts they fly at night. We light trapped some females but we dont know if they will disprese before of after mating. this could affect adoption by the growers. Deployment strategies of the pheromone on the commercial nurseries remains an issue for instance how large an area around new greehouses needs to be covered? Surrounding an entire nursery of a couple hundred acres does not seem reasonable.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.