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Project Leader(s): Jody Gangloff-Kaufmann
and Jillanne Burns, Suffolk CCE with collaborator Tamson Yeh, Nassau CCE.
Cooperator(s): Al Arnold, Hauppauge School
District, Suffolk Co.
Ed Matthews, Suffolk County Parks
Type of grant: Implementation,
continuing
Project location(s): Hauppauge High School
athletic field, Hauppauge NY
Timber Point Golf Course, Great River, NY
Abstract: The objectives of this
project are to familiarize school athletic field managers and county
golf course workers with turf infesting grubs and alternative management
strategies. The goal is to hold a demonstration project and hands-on
workshop for each audience. Participants will be able to sample for
grubs, recognize damage, use proper thresholds for management decisions,
and gain confidence in non-chemical control options.
Background and justification: White
grubs may be the most important insect pests of athletic turf in New
York. While patchy and sporadic in nature, grubs can cause serious damage
to turf, and to the untrained eye, this damage might resemble other
cultural or disease problems. White grubs are commonly managed with
conventional insecticides, such as chlorpyrifos and carbaryl. As public
awareness focuses on the risks associated with pesticides, and chemicals
like chlorpyrifos are phased out of use, athletic field managers are
forced to seek alternatives. This trend provides an excellent opportunity
for Cornell Extension and the Integrated Pest Management Program to
demonstrate grub sampling, thresholds, and the use of beneficial nematodes
for grub management to practitioners, such as school grounds staff and
golf course managers. Many New York state schools already follow no-pesticide
policies for athletic field maintenance and would benefit from learning
how scout and to use beneficial nematodes, when necessary, to manage
damaging grub populations. In addition, Suffolk County has recently
passed a pesticide phase-out law that will require golf courses to become
nearly organic by January 2002. Golf course managers will need to understand
the alternative pest control options available to them and will benefit
from demonstration of their use.
A successful integrated pest management
program relies on the use of sampling, thresholds, and knowledge of
pest biology. In addition, an important control strategy is the use
of beneficial organisms. The use of beneficial nematodes for white grub
control in turf has been explored for a number of years. It is well
established that several species of nematodes, including Heterorhabditis
bacteriophora and Steinernema glaseri, are effective in many
situations for the control of grubs. Some environmental parameters of
nematode use have been established by researchers in New York, thus
improving the chances of using them successfully.
Previous IPM efforts have focused on
the use of nematodes on golf course turf with more limited demonstrations
in school athletic field turf. Demonstrations were successful in both
situations and it would be of great use to bring this type of information
to schools and golf courses on Long Island. Local need is such that
many school districts are phasing out pesticide use, leaving the field
managers worried that they will have no grub control options. In addition,
county owned and operated golf courses are subject to a pesticide phase-out
law that will leave many workers with little idea of how to manage pests
effectively. Our goal is to give practitioners a working knowledge of
the use of beneficial nematodes for grub control. At the same time,
this project will help practitioners accurately determine whether the
problem is grub related and whether treatment will be necessary. It
will also teach them how to use a biological strategy when necessary.
Objectives:
1. To teach proper grub sampling and
identification
2. To instruct practitioners in the
use of economic thresholds
3. To demonstrate the use of beneficial
nematodes (H. bacteriophora) for control of white grubs
Procedures: Preliminary grub
sampling was done in late August to locate appropriate fields in which
to test the effectiveness of entomopathogenic nematodes for grub control.
Heavily infested areas were identified on a fairway at Timber Point
Golf Course (Suffolk County) and at Hauppauge High School, Hauppauge
NY (Suffolk County). Sampling indicated that grubs (mostly Oriental
beetles) in each area had surpassed the threshold of 8-10/sq ft, or
1 per 4" diameter golf course cup cut. Four treatments plus one
control were applied in a randomized complete block design plot in each
location. Each treatment was 3’x3’ square. Treatments included:
H. bacteriophora, S. carpocapsae, a newly
marketed species, Heterorhabditis marilatus, and a new formulation
of H. bacteriophora from BioWorks, Inc. All were applied at a
rate of 1 billion per acre with _" of water, by hand application.
This procedure was slightly different from the original plan of applying
nematodes of the same species and supplier at two different rates. Unexpectedly,
we were offered the new H. marilatus and the new formulation
from BioWorks, so we decided to compare effectiveness by species/formulation
rather than by rate.
Analysis of the plot was to be conducted
as a workshop to be held in each location. Hauppauge school district
had generously offered to host all employees of any other school district
interested in attending the workshop. All municipal golf course employees
of Suffolk County were to be invited and encouraged to attend the workshop
at Timber Point.
Results and discussion: As a
result of the events of mid-September, our hands-on workshops were delayed.
Due to later budget constraints we decided not to hold the workshops
at all. To salvage the project, we chose to analyze the effectiveness
of the nematode applications by quantifying the numbers of grubs in
each plot, both alive and dead. These data were collected on October
2nd by randomly selecting four 4" cup cores, using a
standard golf course cup cutter. Cores were examined for live and dead
grubs. Statistical analysis was performed on the number of remaining
live grubs in each plot. The majority of grubs collected were Oriental
beetles. A smaller number were Asiatic garden beetles. Results showed
that the number of grubs found alive at each location was greatly different,
as might be expected. Timber Point Golf course was more heavilty infested
with grubs by late September than the athletic field at Hauppauge School
District. This may have been because Timber Point golf course is irrigated
on a regular basis, whereas Hauppauge SD fields are not irrigated. Another
factor may have been the enormous presence of ants at Hauppauge. A gigantic
ant colony was discovered in and nearby our plot that stretched for
dozens of square feet beneath the turf. Ant predators may have contributed
to lower numbers of grubs in this field.
Comparison of the data by two-way
ANOVA (by reps and treatments) yielded no significant differences in the
numbers of live grubs and therefore no measureable difference between
the nematode treatments (p=0.964). Variation within and between plots
was high and this may have obscured results. Although many grubs
collected from plots appeared to be or may have been infected with
nematodes, infection was not detectable in any grubs under a dissecting
microscope. This may have been due to the delay of our collection date
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