Download Lincoln Pond, Aquatic Moth Final Report, 2002

Augmentation of the Aquatic Moth, Acentria ephemerella,
for Control of Eurasian watermilfoil, Myriophyllum spicatum
Lincoln Pond/Milfoil Control Project Year 3 – 2002
Contract LC991923-01
LC-IM 98-02-D
0980-004-001
Prepared for:
Lake Champlain Basin Program
Prepared by:
Anita L. Deming (Cornell Cooperative Extension of Essex County)
Index
Executive Summary………………………………………………………………….. .2
Introduction...........................................................................................................2
Goals for 2002....……………………………………………………………………….3
Methods Used
Aquatic Plant Biomass Measurements.…………………………….……….3
Herbivore Population Surveys by Apical Stem Sampling…………………4
Combined stem length of milfoil ……………………………………………..5
Original Releases ……………………………………………………………………..5
Results of 4 years of sampling ……………………………………………………....6
Table 1 Summary of total biomass ………………………………………….7
Table 2 summary of tip sampling…………………………………..………...8
Observed Moth Impacts on Milfoil …………………………………………...9
Chart 1 Moth and Weevil Density at Lincoln Pond 2000.…………….…. 10
Chart 2 Moth and Weevil Density at Lincoln Pond 2001.…………… .….11
Chart 3 Biomass of Milfoil in 2002 ……….........……………………...……12
Chart 4 Combined Stem Length of Milfoil 2002 …………………….……12
Educational Efforts……………………………………………………………….…..13
Conclusions.………………………………………………………………….……….13
Appendices.
LP 2002-1 Map of release sites and GPS coordinates……………….…..14
And map of 2000 milfoil beds
LP 2002-2 Lincoln Pond Aquatic biomass of control sites………………..16
LP 2002 – 3 Total Stem Length and Biomass of Milfoil in B……………...19
LP 2002 – 4 Charts of Weevil and Moth Tip Damage……………………..20
LP 2002 – 5 Educational Releases……………………………………….…26
LP 2002 – 6 Chart of Actions…………………………………………….…..31
Lincoln Pond/Milfoil 2002 Report
2
Executive Summary
Lincoln Pond is a 600-acre, modestly productive lake in Elizabethtown, NY with a
spreading population of a noxious exotic plant, Eurasian watermilfoil (Myriophyllum
spicatum). “Milfoil” is a nonnative plant that frustrates recreational use of water bodies and
outcompetes native aquatic plants by early stem elongation that reaches the water surface
quickly and forms a canopy shading the other aquatic plants.
There are several insects that eat milfoil, limit its growth, and keep it from forming a
canopy in some situations. One of these insects is the aquatic macrophyte moth, Acentria
ephemerella. “The moth” was augmented into various areas of Lincoln Pond over two years.
None of these introductions appear to have significantly changed the background levels of
moths in Lincoln Pond nor to have had a significant impact on milfoil in the Pond, although
there was one significant decrease in milfoil in one mid-lake plot following augmentation.
Fish predation on the moths is a likely cause for their lack of survival. This study and
research from other locations focus attention on the sunfish as the fish most likely to be
interfering with the moth’s potential for controlling milfoil. Follow-up studies are in
progress.
Introduction
Lincoln Pond: Problem and Approach
Lincoln Pond is a 600-acre oligio-mesotrophic lake in Elizabethtown, NY with a
maximum depth of 29 feet. There are three public boat launches, a State campground, and
103 private camps on the Pond. More than a decade ago, Eurasian watermilfoil, hereinafter
referred to as “milfoil”, was introduced, presumably at one of the boat launches, and it has
been spreading throughout the Pond ever since. In 1997, a detailed survey of the milfoil beds
showed 118 pond acres recreationally impaired by dense milfoil. Currently, there are 23
native aquatic macrophyte species not eliminated by milfoil. There are about 450 acres of
Lincoln Pond with muddy bottoms that are less than 15 feet deep, which could become
covered by milfoil. Milfoil displaces native aquatic plant vegetation, chokes the water
column, affects the fishery, and impairs the public use of ponds and lakes that it infests.
Twenty-five camp owners have complained that they are unable to swim at their beaches
without pulling milfoil three to four times per summer.
The Lincoln Pond Association and the Town of Elizabethtown prefer a natural control
approach as opposed to the use of chemicals, harvesters, mats, winter drawdowns, or
dredging. They agreed to work together to develop and implement a weed management plan
to manage milfoil. They desired herbivores be used to control the spread of milfoil.
Cornell University’s aquatic plant researchers (Cornell University Research Ponds
[CURP], Ecology and Evolutionary Biology Department) were interested in conducting a
project that was well documented in order to obtain insight into the impact of milfoil
herbivores and into the effects of herbivore augmentations made with milfoil control goals.
Much of the existing milfoil herbivore information was confounded by other control
methodologies implemented near or at the same time, or by not obtaining pre-release data on
Lincoln Pond/Milfoil 2002 Report
3
the lake system involved. Results from documented milfoil weevil (Euhrychiopsis lecontei)
augmentations had been and continue to be variable. We needed additional information to
evaluate the success of herbivore augmentations. CURP, NY Department of Environmental
Conservation staff, and our local decision making team (DMT) committee established to
address the milfoil challenge and recommended studying an aquatic macrophyte moth
(Acentria ephemerella; hereinafter referred to as “the moth”) as a potentially effective
herbivore; Middlebury College and VT Agency of Natural Resources recommended
additional studies with the milfoil weevil. Since the milfoil weevil was being studied
extensively elsewhere, we opted to pursue a study with the moth.
Cornell Cooperative Extension along with Cornell University’s aquatic plant
researchers released approximately 10,000 moth larvae in June 2000, 300 moth pupae and
4500 moth larvae in June 2001, and 15,000 larvae in October 2001. Our survey showed very
few surviving from the 2000 release. However, survival of larvae from the 2001 releases
appeared greater and was encouraging. Additional details of these releases are presented
below.
Goals for 2002

Monitor previous moth release sites to see if there were any impacts from releases
for:
o biomass (weight) of each species of naked eye visible aquatic plant, and
o herbivorous insect activity in Lincoln Pond.
Methods Used
Aquatic Plant Biomass Measurements
Milfoil biomass measurements at four Locations were compared to a baseline
measurement recorded on September 8, 1999 to determine if milfoil density changed over
time. Biomass measurements were taken October 14, 2000, October 20, 2001, and August
17, 2002 in 100 meters by 100 meters square (quadrat) sampling locations where the mean
water depth was 1.5 – 3.0 meters. At each sampling location, we tossed a 0.25m2 quadrat
frame into the water 20 times and thus selected 20 random 0.25m2 quadrat samples. A
Cornell University Research Pond (CURP) diver using an air buoy underwater breathing
apparatus hand-harvested all above sediment plant biomass inside each tossed quadrat frame.
The diver delivered harvested samples to a boat, and we placed each sample in an
individually marked plastic bag. Samples were stored on ice for transportation to the CURP
laboratory. In the CURP laboratory the samples were refrigerated until analyzed unless it
was determined that they could not be analyzed within two weeks, in which case they were
frozen for later analysis.
At the laboratory, samples were washed and any non-plant material was removed
from the sample after which the sample was separated by individual species. We oven-dried
the separated plant species at 105 o C for 48 hours and measured the dry weight of each
species. With these dry weights, we calculated the mean biomass for each plant species at
Lincoln Pond/Milfoil 2002 Report
4
each sampled Location in the Pond. The resulting data were expressed both in terms of
grams of dry weight per square meter and as a percentage of the total harvested biomass.
After the evaluation of the 1999-biomass data, and noting the small amount of
variation between the sampled 0.25m2 quadrat, we tested statistically for the number of
quadrats required to give us significant differences in the biomass measure. We determined
that we would not loose statistical power in reducing sample size from 20 to 10 quadrats
(0.25m2) because of the quadrat size measured and the small variability between sample
quadrat.
See Appendix LP2002 – 2 for the data sheets.
Herbivore Population Surveys by Apical Stem (“Tip”) Sampling
Insect activity was measured twice in 2002 following herbivore releases in 2000 and
2001. At each of the six Locations (A, B, C, D and B1 and B 2), 25 apical stems (“tips”)
were collected and examined. This occurred on July 15th and August 5th of 2002. (See
Appendix LP 2002 – 1 for map of sites.)
We collected twenty-five apical stems (top, growing part of the milfoil stem),
hereafter referred to as “tips”, each having a length of 25 centimeters. Milfoil tips are the
parts of the plant with the greatest number and diversity of herbivorous insects because it
possesses nutritious, edible new growth and provides concealment and protection with
greater leaf density. Since most milfoil herbivory is in the top 25 centimeters of the stem, a
25-centimeter sample provides a good section for quantifying herbivory.
At each sampling location, we randomly collected a series of plant stem samples
using a grapple hook. We lifted the samples into the boat where we randomly selected 25
milfoil stems from the milfoil plant samples by choosing the basal end (to ensure the choice
was “blind”). We then pinched off the top 25 cm of each stem for our apical stem (“tip”)
sample. We placed each tip sample into an individually marked plastic zipper bag labeled
with an identification number, the sample location, and date. We stored all tips on ice in an
insulated chest for transport to the CURP laboratory.
In the laboratory we refrigerated all samples that we planned to analyze within two
weeks and froze all others. At the time of examination, we placed each tip under a
stereoscopic dissecting microscope. We dissected each tip recording numbers of each
herbivore, life stage(s) present, and an evaluation of the entire tip which included evidence of
herbivore use (retreats, cocoons, or pupal chambers), and milfoil tissue damage (leaflet
damage, stem mining, missing or grazed buds).
For each tip, we made a quality assessment and quantified all milfoil tissue damage
using a CURP standard scoring system. Using this standard CURP protocol, we are able to
determine which herbivore (moth, weevil, Caddisfly or midges) was most likely responsible
for which damage and to assess the amounts of damage caused the milfoil by each of the
herbivores.
Lincoln Pond/Milfoil 2002 Report
5
The baseline tip surveys were completed in June 17, July 29, and August 9 of 1999.
Additional tip surveys were made on May 25, June 15, 8 July, 5 August, and 16 September
2000; June 23, July 2, August 18, and October 18, 2001; and July 15 and August 5, 2002.
Combined Stem Length of Milfoil
The biomass samples that were collected from the 10 quadrats were measured for
length of plants in centimeters. Each length was combined with the others of the same
species and reported as combined tip length. This measurement was added at the end as there
seemed to be a shortening of the milfoil in the one release site B2. This was confirmed by
comparing the control B and the treatment plot B1 (summer of 2001 release only).
Original Releases
In 1978 a survey of Lincoln Pond showed that there was no appreciable milfoil
anywhere in the lake. In the mid 1980’s the County lowered the water level to repair the
causeway between the two sections of the lake. Following the draining of the northern
section of the lake, shore owners began to complain of a weed that was impacting the mid
section of the lake. It was identified as Eurasian watermilfoil. In 1993 Robin Ulmer of the
Boquet River Association mapped about 60 acres of “impacted” lakebed. In 1997, John
Deming Land Surveyor and Steve Lamere, Certified Lake Ecologist, mapped 118 acres of
dense milfoil beds. In 2000, John Deming, Land Surveyor, and Robert Johnson mapped
137.85 acres of dense milfoil.
It appears that the draining of the lake stressed the native vegetation and allowed the
few milfoil plants that were there to gain an advantage. Once started they have been
spreading down stream and along the shoreline where boaters “brought it home” after
boating through the “beds.” We extrapolate the spread of impacted acreage at 5%/year. There
are about 400 acres (66% of the Lake) of potential milfoil habitat in Lincoln Pond (soft
substrate less than 14 feet deep). So far the deepest we have measured milfoil growing is 14
feet.
Site A, C and D are newer sites of infestation. Site B is believed to be the first site as
it is at the boat launch. Site B is also the greatest acreage of milfoil and goes into the deepest
water. Initially we did our releases in Site D as it was the lushest and densest bed. However,
we changed our strategy to Site B when we saw the greatest number of naturally occurring
Acentria were at that site.
Herbivores released were raised at the Cornell University Research Ponds (CURP) in
Ithaca during winter and spring of 2000 and 2001. Please see Appendix LP 2002 – 1 for a
map of the lake and locations of beds and release sites and Appendix LP 2002-6 for a
summary of releases at each site.
1st - On June 14, 2000, we selected milfoil stems from the CURP greenhouse with healthy
small (2nd instar [growth stage]) moth larvae attached and planted them in small peat pots
Lincoln Pond/Milfoil 2002 Report
6
which were lowered into Lincoln Pond two days later. We released approximately ten
thousand (between 8,500 and 11,500) moth larvae on June 16, 2000 in Plot B. The release
sites were 100 square meters (10 meters by 10 meters) each within Plot D, EE and FF (as
displayed in Appendix LP 2002 - 1) (between 4,250 to 5750 larvae at each site) with two
other sites used as short-term controls. However, there were no significant moth results at EE
or FF.
2nd - On June 22, 2001, we released 300 pupae (nearly adult moth larvae in cocoons) at
Location D where we released younger moth larvae in 2000. While such numbers were
nearly insignificant, we wanted to observe any resulting increases in moth populations at
Location D. They were released between the original sites EE and FF along the midline. The
data is reported as M. However, there were no significant results from M.
3rd - We selected later instar moth larvae for another augmentation, anticipating increased
moth larvae survival. We projected that an earlier established, more robust population of
moth larvae would be able to compete more successfully with early weevil populations.
On June 22, 2001, we added moth larvae to a new plot in the northern half of the lake
at Location B, which we had monitored with herbivore surveys since 1999. Location B had
similar milfoil densities to Location D, and is the location where lakeshore owners believe
milfoil first entered the Pond. We recorded a small indigenous population of moths at
Location B in 2000. Since earlier releases were in Plots EE and FF at Location D with a
density of weevils, we released moth larvae in Location B to avoid weevil interference or
confounding data from the earlier release. Augmentation at this site provided an opportunity
to determine if augmenting a small existing population of moth larvae would be an effective
method of establishing larger populations. We released 4500 2nd and 3rd instar (growth stage)
moth larvae in Plot B1 and B2 at Location B. We sampled stems at Location B on August
18, 2001.
4th - In the fourth 2001 augmentation, on October 19, we released 15,000 2nd and 3rd instar
moth larvae, in a resting state, into Plot B2 (10 meters by 10 meters) within Location B. We
left B1 for any long term impact from the 3rd release. Release method and timing were used
to avoid larvae loss due to fish predation since we suspected fish predation was a major
interference with our earlier augmentations.
Results of 4 years of sampling
Biomass
There is quite a range of grams of dry weight per meter squared (g DW/m²) of milfoil
and other vegetation from year to year even in the control areas. This has a lot to do with the
warmth of the summer and sunlight and the time of year. We could not attribute any specific
benefit to the Acentria releases.
Control Site A had a decrease in milfoil percent and grams of dry weight of milfoil.
Control parts of Sites B, C, and D actually had an increase in the Dry weight of milfoil.
Lincoln Pond/Milfoil 2002 Report
7
Table 1. Summary of total biomass. g DW/m² = grams of dry weight per meter squared.
Site g DW/m² of vegetation
g DW/m² of milfoil
% milfoil % bladderwort
1999 – control year
A
76.91
B
50.28
C
85.36
D
37.28
69.56
27.23
67.61
30.09
90.4
54.2
79.2
80.7
0.8
18.5
5.4
3.8
2000
A
B
C
D
29.36
64.13
56.35
59.72
24.31
20.03
31.54
56.39
82.8
31.2
56.0
94.4
5.0
38.5
24.0
0.0
2001
A
B
C
D
27.20
56.50
47.04
58.26
19.83
21.47
27.54
54.98
72.9
38.0
58.6
94.4
3.7
25.6
13.6
0.0
2002
A
B
63.04
86.58
32.39
55.69
66.33
57.66
24.72
111.04
135.42
51.4
64.3
0.3
3.0
86.5
96.0
0.9
0.06
Control Plot B
Plot B1
Plot B2
C
D
128.38
141.02
Lincoln Pond/Milfoil 2002 Report
8
Table 2 Summary of Tip Sampling:
Summary of moth and weevil numbers by date from 1999 to 2002. Numbers are insects per
25 apical stem (“tip”) samples found at Location: A, B, C, D, in treated plots EE and FF at
location D, and in plots B1 and B2 at location B.
Location
A
Date
M
W
M
W
M
W
M
W
6/17/99
7/29/99
9/9/99
total 1999
0
0
5
0
7
0
0
1
0
0
6
3
0
0
0
7
7
2
1
1
0
5
2
7
5/25/00
6/15/00
7/8/00
8/5/00
9/16/00
total 2000
0
3
3
0
0
6/26/01
7/2/01
8/18/01
10/18/01
total 2001
0
0
0
0
7/15/02
8/5/02
1
0
total 2002
B
0
8
5
3
0
0
2
7
0
5
2
10
0
1
11
0
1
7
1
0
3
1
C
1
1
1
4
1
6
4
8
0
0
3
0
0
1
0
0
0
0
0
0
0
0
D
0
6
12
16
0
7
7
4
0
8
11
0
0
0
0
0
0
0
0
0
0
0
EE
FF
B1
B2
Control
(D) (D) (D) (D) (B) (B) (B) (B) totals
0
0
3
16
2
24
21
0
0
0
4
M
0
2
0
W
6
20
3
M
0
0
0
W
M
W
M
W
2
21
0
0
0
1
0
1
3
0
0
1
0
1
2
M
1
2
W
12
22
5
12
8
46
10
1
3
15
5
21
11
39
0
3
29
79
1
37
7
34
1
19
0
0
9
90
4
13
1
20
5 43
We performed three exploratory herbivore surveys in June, July and August of 1999,
before the release of any milfoil moth caterpillars, and found evidence 8 times of moth
activity (average 0.02 per stem) and few weevils (0.12 per stem). Previous work in NY
showed that the weevil seemed to prefer smaller water bodies and the moth was found in
larger lakes. We found very few of either.
In 2000, after our early release of small young larvae, we saw evidence of moth
activity twice at our release site EE and FF, but a large number of weevils had came in on
their own. There was no decrease in the overall biomass over the years from this intense
infestation of weevils.
In 2001 the evidence of moth survival was poor. Only site B was showing any moths
through that summer, and they were from a “natural” population. We decided to try a mid
summer release of larger moth larvae at two new sites B1 and B2. However, the tip sampling
did not show any evidence of moth activity in October of 2001.
Lincoln Pond/Milfoil 2002 Report
9
As a last resort, we tried a fall release of “resting” larva in October of 2001 only at
site B2. The following summer, we did see evidence of herbivory, but few insects
themselves remained. Also, we saw a visible difference in the density and length of the
milfoil in the fall release site B2. We believed the caterpillars did their damage early in the
spring when the milfoil was small and prevented the rapid elongation. In the biomass
sampling there is a dramatic change in the weight of milfoil and the total tip length of milfoil
in the release site B2, compared to the surrounding control of Site B and adjacent plot B1
where only a summer release was made.
Observed Moth Impacts on Milfoil
2000
Our first two surveys of 2000 revealed few herbivores (average of 0.07 moth larvae
and 0.08 weevils per stem). Therefore, we decided that Lincoln Pond would be a good
candidate to test augmentation. Since there were few insects to start with, we anticipated an
increased population of moths.
On July 8, the first post-augmentation herbivore survey on plots EE and FF yielded
unexpected results. We found few moth larvae, but more milfoil weevils were present than
we had counted in previous Lincoln Pond surveys. The milfoil weevil count, 0.34 per stem,
continued to rise in subsequent surveys. In this first survey, we found moderate to high
levels of milfoil weevil damage and some less frequent indications of moth damage on the
milfoil plants.
We recorded a large increase in milfoil weevils on tips (average of 0.84 per stem) at
Locations C, D, and at our moth augmentation Plots EE and FF, both within Location D, in
the August 5 survey. This population of milfoil weevils at Locations C and D was
significant. Our final survey on September 16 revealed no moth larvae, and only a few
milfoil weevils, as most milfoil weevil adults had gone to shore for the winter. Many milfoil
stems from this last survey had milfoil weevil damage while some displayed new, late-season
regrowth. It was clear that there were more milfoil weevils than moth larvae in Lincoln
Pond. Nevertheless, neither reached the theoretical critical mass of one per stem for moth
larvae or three per stem for milfoil weevils. The populations varied over the summer.
Location B revealed the most moth herbivory. Locations C and D showed the most weevil
herbivory.
The year 2000 moth augmentation was not a success, but did yield insights into the
moth augmentation process. The unexpectedly large population of milfoil weevils in Lincoln
Pond was an important factor in our research that had to be considered. During 2000, we
recorded aquatic moth larvae in Lincoln Pond, however, they appeared to be naturally
occurring, and not the result of our augmentation at Plots EE and FF. We evaluated our
observed herbivore population differences between locations and dates statistically. We
moved our focus to the influence of milfoil weevils on moth populations.
2001
In 2001 milfoil weevils again out numbered moths in Lincoln Pond. Location B
continued to hold the largest population of moth larvae, but that was a natural population as
Lincoln Pond/Milfoil 2002 Report
10
none were augmented in that Location until after the July 2, 2001 tip sampling when they
were added to Plots B1 and B2
We were unable to find any evidence of a moth population increase at Location D on
the August 18 sampling following the introduction of 300 pupae in June. The results of that
stem sample survey revealed only a few moth larvae in Plots B1 and B2 at Location B.
There was no significant increase over expectations for indigenous moth larvae.
2002.
Once again weevils out numbered the moths and tip sampling showed no significant increase
in the moth larva populations using our methodology.
Chart 1 Moth and Weevil Density on Apical Stems in 2000
Moth Density
Moths / Apical Stem
Moth Populations at Lincoln Sites A - FF
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
Moth larvae added 6/16
at D into two locations
EE and FF
n=25 apical
stems
+ 1SE
B
B
B
B
C
A
A
C D
A
5/25
C D
FF
D DD EE
6/15
EE
C D
A
7/08
FF
A B C D EE FF
8/05
9/16
2000
Weevil Density
Weevils / Apical Stem
Weevil Populations at Lincoln Sites A - FF
EE
Moth larvae added 6/16
at D into two locations
EE and FF
1.0
FF
n = 25 apical
stems
+ 1SE
C D
C
0.5
B
DD
EE
C
B
A
D
B
EE
FF
0.0
A
C D
5/25
D
A
A
B
B
D
6/15
A
7/08
2000
8/05
C
9/16
FF
Lincoln Pond/Milfoil 2002 Report
11
Chart 2 Moth and Weevil Density on Apical Stems in 2001
Moth Density
Moths / Apical Stem
Moth Populations at Lincoln Sites A - D, M
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
Added moth
larvae into
B1 on 6/22
n=25 apical
stems
+ 1SE
Added moth pupae
into D on EE center
line on 7/02
B
B
B
C
A
D
A
C
6/23
D
A
C
7/02
D
M
8/18
2001
Weevil Populations at Lincoln Sites A - D, M
n = 25 apical
stems
+ 1SE
D
Weevil Density
Weevils / Apical Stem
D
1.0
0.5
B
A
C
B
C
B
C
A
M
0.0
A
D
6/23
7/02
2001
M is the midline between EE and FF.
8/18
Lincoln Pond/Milfoil 2002 Report
12
Chart 3 and 4 There is a significant difference in the combined stem length and in the
biomass in plot B2 from the B1 summer application and the control B. Mean (n = 10 sampled
quadrats) combined stem length (cm) of all milfoil per 0.25m2 quadrate (top), and mean (n =
10 sampled quadrats) dry biomass (g) of all milfoil per m2 (bottom), as the result of
treatments with and without Acentria additions. Treatments labeled with different letters are
significantly different (MWW, p<0.0005).
Chart 3 Milfoil Biomass of milfoil in 2002 in Control Site B and B1 and fall treatment B2
Moth Reduces Watermilfoil Biomass
Biomass (g/m2 )
100
4500 larvae
June 22, 2001
a
a
+1SE
n = 10
15,000 larvae on
Oct. 19, 2001
50
b
0
Control B
B1
B2
July 15, 2002
Chart 4. Combined Stem Length of Milfoil in control site B and B1 and fall treatment B2
Moth Reduces Watermilfoil Stem Length
Total Stem Length (cm)
10000
+1SE
n = 10
a
a
5000
b
0
Control B
B1
Treatment
B2
Lincoln Pond/Milfoil 2002 Report
13
Educational Efforts
Several web sites have been developed presenting several stages of this research.
Once this report is approved we will add it to the sites and
Several web sites have been developed. Please see:




www.eeb.cornell.edu/ponds/page
http://www.fw.umn.edu/research/milfoil/milfoilbc.html
http://www.cce.cornell.edu/essex/milfoil/milfoil.html
http://cce.cornell.edu/counties/Essex/milfoil/moth.html
Please see Appendix LP 2002 - 4
Two Press Releases were developed describing milfoil moth and fish predation and
promoting a sunfish derby.
A handout for landowners around the lake and for campers at the State Campsite were
developed and distributed.
An Article was developed and was distributed through the North Adirondack Agricultural
News (3500), Town and Country (900), Boquet River Association Newsletter (300), and Au
Sable River Association (250).
Two public service announcements were developed for WIPS in Crown Point and
Ticonderoga and a half hour interview was conducted on August 2003.
Conclusions
This moth augmentation project generated interest from lake associations state-wide.
The concept that an insect already present in NY could control the noxious milfoil plant is
attractive since it would involve modest expense and would be environmentally safe. Several
groups are looking for more information on our project.
We cannot claim success since we have not produced an increased population of
moths capable of exerting widespread control. We did, however, document an adverse
impact on milfoil (reductions in stem length and biomass) in plots where moths were
introduced. Our focus is increasingly directed toward fish predation as the interfering agent
in our augmentation process.
Milfoil herbivore predation probably comes from a number of animals representing
various taxonomic groups. We need not, however, focus on all predators. We should
identify those predators that exert significant control on milfoil herbivores. Predation by
sunfish may be a key limiting factor on moth herbivory success. This contention is supported
by data from studies in Lebanon Reservoir, from observations and studies made at the CURP
ponds, and aquaria observations made by Robert Johnson that occupied macrophyte moth
refuges, originally present when sunfish were introduced to aquaria with milfoil and aquatic
macrophyte moths, were missing from milfoil stems at the end of the experiment.
Lincoln Pond/Milfoil 2002 Report
14
Appendix LP 2002-1 Scale 1 to 22,400 or 0.5 inches = 500 m
Lincoln Pond Moth Augmentation Sites
Scale: 1 : 22,400
500 m
Lincoln Pond/Milfoil 2002 Report
Map of Lincoln Pond Milfoil beds 2000
15
Lincoln Pond/Milfoil 2002 Report
16
Appendix LP 2002 – 2
Lincoln Pond Aquatic Plant biomass on 8-17-2002
Quadrat (0.50m*0.50m) Species Composition and Species Dry Weight (g/0.25m2)
Location A 2002
SITE PLANT SPECIES
A
A
A
A
A
A
A
A
ELODEA CANADENSIS
MYRIOPHYLLUM SPICATUM
NIJAS FLEXILIS
NITELLA ssp.
POTAMOGETON PRAELONGUS
POTAMOGETON PUSILLUS
UTRICULARIA spp.
VALLISNERIA AMERICANA
TOTAL
A
A
A
A
A
A
A
A
ELODEA CANADENSIS
MYRIOPHYLLUM SPICATUM
NIJAS FLEXILIS
NITELLA ssp.
POTAMOGETON PRAELONGUS
POTAMOGETON PUSILLUS
UTRICULARIA spp.
VALLISNERIA AMERICANA
TOTAL
DW02-1 DW02-2 DW02-3 DW02-4 DW02-5 DW02-6 DW02-7 DW02-8
2.57
9.73
0.00
0.03
0.00
0.12
0.01
2.09
14.55
1.83
10.05
0.04
0.00
0.00
0.01
0.00
4.12
16.05
1.26
15.26
0.05
0.05
0.00
0.03
0.00
5.31
21.97
2.38
0.45
0.16
0.04
0.09
0.03
0.00
9.41
12.56
2.95
8.27
0.11
1.38
0.28
0.37
0.01
5.94
19.31
0.77
0.01
0.48
0.08
0.00
0.00
0.21
9.30
10.85
1.40
16.60
0.00
0.00
0.00
0.01
0.00
4.82
22.83
0.58
15.93
0.01
0.05
0.00
0.05
0.17
0.00
16.79
DW02-9 DW02-10 tot02DW %02DW g/.25m² gDW/m²
3.29
0.31
0.00
0.08
0.00
0.07
0.00
3.96
7.71
2.78 19.81 12.57
4.36 80.97 51.38
0.00
0.85
0.54
1.62
3.34
2.12
0.00
0.36
0.23
0.05
0.74
0.47
0.00
0.40
0.26
6.18 51.13 32.44
14.99 157.61 100.00
1.98
8.10
0.09
0.33
0.04
0.07
0.04
5.11
15.76
7.92
32.39
0.34
1.34
0.15
0.29
0.16
20.45
63.04
Location B 2002
SITE PLANT SPECIES
B
B
B
B
B
B
B
B
B
B
B
CHARA VULGARIS
ELODEA CANADENSIS
MYRIOPHYLLUM SPICATUM
NAJAS FLEXILIS
NITELLA ssp.
POTAMOGETON AMPLIFOLIUS
POTAMOGETON PRAELONGUS
POTAMOGETON PUSILLUS
SAGITTARIA ssp.
UTRICULARIA ssp.
VALLISNERIA AMERICANA
TOTAL
B
B
CHARA VULGARIS
ELODEA CANADENSIS
DW02-1 DW02-2 DW02-3 DW02-4 DW02-5 DW02-6 DW02-7 DW02-8
0.00
0.37
12.48
0.00
0.11
0.00
0.00
0.02
0.15
0.94
0.89
14.96
0.00
0.21
8.45
0.00
0.02
8.68
1.83
0.01
0.00
0.43
4.55
24.19
0.00
0.38
21.47
0.15
0.11
1.29
1.97
0.00
0.25
0.60
0.36
26.58
0.00
0.22
7.92
0.12
0.22
0.13
0.00
0.01
0.21
1.98
1.24
12.04
0.00
0.38
6.17
0.03
0.00
8.97
0.00
0.06
2.87
0.30
3.85
22.63
0.00
2.33
21.48
0.06
0.10
0.00
0.00
0.03
0.00
0.10
1.91
26.02
DW02-9 DW02-10 tot02DW %02DW g/.25m² gDW/m²
0.01
0.16
0.00
0.52
0.01
5.05
0.01
2.34
0.00
0.51
0.00
2.02
0.00
0.08
11.17
0.05
0.01
8.36
0.00
0.00
0.43
1.29
0.01
21.40
0.00
0.40
10.63
0.31
0.03
0.00
0.00
0.00
0.96
0.55
3.97
16.87
Lincoln Pond/Milfoil 2002 Report
17
DW02-9 DW02-10 tot02DW %02DW
B
B
B
B
B
B
B
B
B
B
B
CHARA VULGARIS
ELODEA CANADENSIS
MYRIOPHYLLUM SPICATUM
NAJAS FLEXILIS
NITELLA ssp.
POTAMOGETON AMPLIFOLIUS
POTAMOGETON PRAELONGUS
POTAMOGETON PUSILLUS
SAGITTARIA ssp.
UTRICULARIA ssp.
VALLISNERIA AMERICANA
TOTAL
0.01
0.16
17.98
0.08
0.00
3.01
0.09
0.03
0.48
0.13
4.86
26.83
0.00
0.52
21.47
0.08
0.03
0.26
0.00
0.00
0.00
0.14
2.44
24.95
0.01
5.05
139.22
0.88
0.64
30.69
3.89
0.17
5.35
6.47
24.08
216.44
0.01
2.34
64.32
0.41
0.29
14.18
1.80
0.08
2.47
2.99
11.12
100.00
g/.25m² gDW/m²
0.00
0.51
13.92
0.09
0.06
3.07
0.39
0.02
0.53
0.65
2.41
21.64
0.00
2.02
55.69
0.35
0.25
12.28
1.56
0.07
2.14
2.59
9.63
86.58
Location C 2002
SITE PLANT SPECIES
C
C
C
C
C
C
C
C
C
C
ELODEA CANADENSIS
MYRIOPHYLLUM FARWELLII
MYRIOPHYLLUM SPICATUM
NAJAS FLEXILIS
NITELLA ssp.
POTAMOGETON AMPLIFOLIUS
POTAMOGETON PUSILLUS
SAGITTARIA ssp.
UTRICULARIA ssp.
VALLISNERIA AMERICANA
TOTAL
DW02-1
DW02-2
0.03
0.00
38.44
0.02
1.14
0.00
0.00
0.00
0.03
0.00
39.66
0.55
0.00
32.84
0.02
0.41
0.97
0.01
0.00
0.32
0.02
35.12
DW02-3 DW02-4 DW02-5 DW02-6 DW02-7 DW02-8
0.08
0.00
39.00
0.00
0.06
0.00
0.00
0.00
0.45
0.00
39.59
0.07
0.36
27.42
0.07
0.42
0.00
0.00
0.00
0.04
1.19
29.56
DW02-9 DW02-10 tot02DW %02DW
C
C
C
C
C
C
C
C
C
C
ELODEA CANADENSIS
MYRIOPHYLLUM FARWELLII
MYRIOPHYLLUM SPICATUM
NAJAS FLEXILIS
NITELLA ssp.
POTAMOGETON AMPLIFOLIUS
POTAMOGETON PUSILLUS
SAGITTARIA ssp.
UTRICULARIA ssp.
VALLISNERIA AMERICANA
TOTAL
0.19
0.00
22.74
0.00
0.14
0.00
0.00
0.58
0.21
0.00
23.86
0.08
0.02
39.04
0.03
0.13
0.00
0.06
0.00
1.30
0.04
40.70
2.01
30.57
277.60
0.14
2.73
0.97
0.09
2.74
2.88
1.25
320.96
0.62
9.52
86.49
0.04
0.85
0.30
0.03
0.85
0.90
0.39
100.00
0.02
0.00
21.22
0.00
0.08
0.00
0.00
1.27
0.12
0.00
22.71
0.05
30.19
0.02
0.00
0.09
0.00
0.00
0.52
0.40
0.00
31.26
g/.25m² gDW/m²
0.20
3.06
27.76
0.01
0.27
0.10
0.01
0.27
0.29
0.12
32.10
0.80
12.23
111.04
0.05
1.09
0.39
0.04
1.10
1.15
0.50
128.38
0.92
0.00
29.66
0.01
0.21
0.00
0.02
0.32
0.02
0.00
31.15
0.01
0.00
27.22
0.00
0.05
0.00
0.00
0.05
0.01
0.00
27.34
Lincoln Pond/Milfoil 2002 Report
18
Location D 2002
SITE PLANT SPECIES
D
D
D
D
D
D
D
D
D
D
ELODEA CANADENSIS
MYRIOPHYLLUM FARWELLII
MYRIOPHYLLUM SPICATUM
NAJAS FLEXILIS
NITELLA ssp.
POTAMOGETON AMPLIFOLIUS
POTAMOGETON PUSILLUS
SAGITTARIA ssp.
UTRICULARIA ssp.
VALLISNERIA AMERICANA
TOTAL
D
D
D
D
D
D
D
D
D
D
ELODEA CANADENSIS
MYRIOPHYLLUM FARWELLII
MYRIOPHYLLUM SPICATUM
NAJAS FLEXILIS
NITELLA ssp.
POTAMOGETON AMPLIFOLIUS
POTAMOGETON PUSILLUS
SAGITTARIA ssp.
UTRICULARIA ssp.
VALLISNERIA AMERICANA
TOTAL
DW02-1
DW02-2
0.48
0.00
29.43
0.00
0.03
0.00
0.01
0.00
0.03
0.00
29.98
1.18
0.00
36.58
0.00
0.03
1.91
0.00
0.00
0.00
0.00
39.71
DW02-3 DW02-4 DW02-5 DW02-6 DW02-7 DW02-8
1.83
0.00
35.29
0.00
0.08
0.56
0.04
0.00
0.02
0.00
37.81
1.36
0.00
30.26
0.00
0.05
0.00
0.01
0.00
0.02
0.00
31.70
DW02-9 DW02-10 tot02DW %02DW
0.09
0.00
37.32
0.00
0.05
1.42
0.02
0.00
0.01
0.00
38.91
0.17
0.00
32.96
0.00
0.15
1.37
0.01
0.66
0.00
0.21
35.51
6.71
0.00
338.55
0.01
0.73
5.32
0.15
0.66
0.20
0.21
352.54
1.90
0.00
96.03
0.00
0.21
1.51
0.04
0.19
0.06
0.06
100.00
0.10
0.00
46.68
0.00
0.03
0.00
0.00
0.00
0.01
0.00
46.83
0.98
0.00
23.59
0.00
0.07
0.05
0.05
0.00
0.03
0.00
24.75
g/.25m² gDW/m²
0.67
0.00
33.86
0.00
0.07
0.53
0.01
0.07
0.02
0.02
35.25
2.69
0.00
135.42
0.00
0.29
2.13
0.06
0.26
0.08
0.08
141.02
0.18
0.00
26.85
0.00
0.22
0.00
0.01
0.00
0.00
0.00
27.26
0.35
0.00
39.59
0.01
0.04
0.01
0.00
0.00
0.09
0.00
40.08
Lincoln Pond/Milfoil 2002 Report
19
Appendix LP 2002-3 Total stem length (cm / 0.25m2) and dry biomass (g / m2) from
7/15/02 comparing the control plot B to a summer 2001 moth augmentation plot B 1 and a
fall 2001 moth augmentation plot B 2. Ten 0.25m2 samples above sediment are reported
below for total length and dry biomass.
Sample
B total stem length (cm/0.25m2)
B1 total stem length (cm/0.25m2)
B2 total stem length (cm/0.25m2)
1
2
3
4
5
6
7
8
9
10
7307
4281
11705
7706
5685
3444
11498
5204
7093
5375
7251
4975
4434
5228
6832
7573
7360
4922
4340
9274
3852
2285
3092
813
2491
1891
1929
2690
3485
3022
Mean
Stdev
6930
2800
6219
1661
2555
883
Sample
B biomass (g/m2)
B1 biomass (g/m2)
B2 biomass (g/m2)
1
2
3
4
5
6
7
8
9
10
69.4
51.8
92.24
72.76
56.92
29
123.4
51.04
71.24
45.52
67.08
50.52
43.92
46.96
56.6
73.2
59.16
46.2
43.56
89.36
33.2
26.72
40.2
0.19
26.08
21.48
25.72
18.44
29.8
25.32
Mean
Stdev
66
27
58
15
25
11
Lincoln Pond/Milfoil 2002 Report
20
Appendix LP 2002 – 4 Charts of Weevil and moth tip damage by location.
Estimated Weevil Populations at Location A
Weevils / Apical Stem
1.0
+1SE
n=25
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
7/15
8/5
2002
Apical Stem Damage Rating
Herbivore Damage to Milfoil at Location A
0
+1SE
n=25
Healthy
1
Minor
2
Moderate
3
Extensive
4
Destroyed
7/15
8/5
2002
Figure C-20. Mean weevils (all life stages) ± 1SE recorded per 25cm apical stem at
Location A (n = 25 apical stems). Herbivore damage to 25cm apical stems (“tips”)of milfoil
at Location A shown as a mean rating ± 1SE of herbivore damage to 25 apical stems.
Herbivore damage ranges from 0 = no damage to 4 = apical tip destroyed.
Lincoln Pond/Milfoil 2002 Report
21
Estimated Weevil Populations at Location B
Weevils / Apical Stem
1.0
+1SE
n=25
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
7/15
8/5
2002
Apical Stem Damage Rating
Herbivore Damage to Milfoil at Location B
0
+1SE
n=25
Healthy
1
Minor
2
Moderate
3
Extensive
4
Destroyed
7/15
8/5
2002
Figure C-21. Mean weevils (all life stages) ± 1SE recorded per 25cm apical stem at
Location B (n = 25 apical stems). Herbivore damage to 25cm apical stems (“tips”)of milfoil
at Location B shown as a mean rating ± 1SE of herbivore damage to 25 apical stems.
Herbivore damage ranges from 0 = no damage to 4 = apical tip destroyed.
Lincoln Pond/Milfoil 2002 Report
22
Estimated Moth Populations at Location B
1.0
+1SE
n=25
Moth / Apical Stem
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
7/15
8/5
2002
Apical Stem Damage Rating
Herbivore Damage to Milfoil at Location B
0
+1SE
n=25
Healthy
1
Minor
2
Moderate
3
Extensive
4
Destroyed
7/15
8/5
2002
Figure C-22. Mean moths (all life stages) ± 1SE recorded per 25cm apical stem at
Location B (n = 25 apical stems). Herbivore damage to 25cm apical stems (“tips”)of milfoil
at Location B shown as a mean rating ± 1SE of herbivore damage to 25 apical stems.
Herbivore damage ranges from 0 = no damage to 4 = apical tip destroyed.
Lincoln Pond/Milfoil 2002 Report
23
Moth Augmented on October 19, 2001
Estimated Weevil Populations at Location B2
Weevils / Apical Stem
1.0
+1SE
n=25
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
7/15
2002
Apical Stem Damage Rating
Moth Augmented on October 19, 2001
Herbivore Damage to Milfoil at Location B2
0
+1SE
n=25
Healthy
1
Minor
2
Moderate
3
Extensive
4
Destroyed
7/15
2002
Figure C-23. Mean weevils (all life stages) ± 1SE recorded per 25cm apical stem at Plot
B2 (n = 25 apical stems). Herbivore damage to 25cm apical stems (“tips”)of milfoil at Plot
B2 shown as a mean rating ± 1SE of herbivore damage to 25 apical stems. Herbivore
damage ranges from 0 = no damage to 4 = apical tip destroyed.
Lincoln Pond/Milfoil 2002 Report
24
Apical Stem Damage Rating
Herbivore Damage to Milfoil at Location C
0
+1SE
n=25
Healthy
1
Minor
2
Moderate
3
Extensive
4
Destroyed
7/15
8/5
2002
Estimated Weevil Populations at Location C
Weevils / Apical Stem
1.0
+1SE
n=25
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
7/15
8/5
2002
Figure C-24. Mean weevils (all life stages) ± 1SE recorded per 25cm apical stem at
Location C (n = 25 apical stems). Herbivore damage to 25cm apical stems (“tips”)of milfoil
at Location C shown as a mean rating ± 1SE of herbivore damage to 25 apical stems.
Herbivore damage ranges from 0 = no damage to 4 = apical tip destroyed.
Lincoln Pond/Milfoil 2002 Report
25
Estimated Weevil Populations at Location D
Weevils / Apical Stem
1.0
+1SE
n=25
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
7/15
8/5
2002
Apical Stem Damage Rating
Herbivore Damage to Milfoil at Location D
0
+1SE
n=25
Healthy
1
Minor
2
Moderate
3
Extensive
4
Destroyed
7/15
8/5
2002
Figure C-25. Mean weevils (all life stages) ± 1SE recorded per 25cm apical stem at
Location D (n = 25 apical stems). Herbivore damage to 25cm apical stems (“tips”)of milfoil
at Location D shown as a mean rating ± 1SE of herbivore damage to 25 apical stems.
Herbivore damage ranges from 0 = no damage to 4 = apical tip destroyed.
Lincoln Pond/Milfoil 2002 Report
26
Appendix LP 2002 – 5 – Press Releases
PRESS RELEASE: Immediately
TITLE: Lincoln Pond Fishing Derby
The Lincoln Pond Association is announcing cash awards for the most sunfish
caught and the most weight of sunfish caught at Lincoln Pond this weekend. In each category
first place will be $30, second is $20 and third is $10. The awards will be made at 6 PM at
the boat launch next to the Lincoln Pond Rd just west of the causeway. You may bring in
your fish from 3 PM to 6 PM or make arrangements with Anita Deming (873-2178 home or
962-4810 work) to deliver your fish earlier. You may catch your fish at any time from now
until Sunday, but please freeze them if they are not fresh. For the size category we will use a
scale. For the number category we will count all fish no matter how small.
The sunfish in Lincoln Pond are stunted because the lake is out of sync with its
carrying capacity. There are so many sunfish that they are eating the milfoil moth caterpillars
that we have released to help control the milfoil. We are trying this fishing derby to bring the
lake back into an ecologically sustainable balance.
Also as a part of this effort, we are asking for a voluntary catch and release on
large bass. The large bass are very efficient at eating small sunfis so we are hoping to
have more of them in the lake for longer.
TITLE: Lincoln Pond Pan-Fishing Derby
Author: Anita Deming, Lincoln Pond Association
There were 6 winners of the Lincoln Pond Pan-Fishing Derby last Sunday. A total of
378 fish were caught at a total weight of 30.3 pounds. This means the average fish was only
1.28 ounces. Pan fish this small are indicative of stunted fish that do not have enough to eat.
There were only 3 Crappies caught, and 25 yellow perch, the rest were pumpkinseeds. We
were surprised that there were no bluegills at all.
The winner for most fish was Matt Little who caught 75 fish. The winner of most
weight was Edward Paquin with 6 pounds and 3 ounces. Second place winners were Mike
O’Day and Rachel Deming. Third place winners were Patrick and Kayla Ellsworth.
The Lincoln Pond Association sponsored this contest to publicize the problem with
too many small fish in Lincoln Pond. These small fish survive on insects, but the Lincoln
Pond Association is trying to use insects to control the milfoil. Therefore, we are looking for
more large fish and are asking for a voluntary catch and release on the Bass in Lincoln Pond.
The Bass are our best predator for eating the sunfish once they are legal to take. Consider
leaving them to grow another 3 or 4 inches before you take them and we will have a superb
trophy bass fishery, and better milfoil control
The Lincoln Pond Association is interested in hearing from fisherman, if they would
like to have a trophy bass fishery at Lincoln Pond. This would mean raising the legal size for
take home. Please call Anita Deming at 962-4810 or write PO Box 37 New Russia NY 12964
to comment.
Lincoln Pond/Milfoil 2002 Report
27
Lincoln Pond Association
President Steve Muller
PO Box 131
Elizabethtown NY 12932
(518) 873-6500 days
(518) 942-3310 evenings
[email protected]
To: Lincoln Pond Campers
The Lincoln Pond Association welcomes you to our wonderful lake. Please take a moment
to review these suggestions to help us keep this a memorable experience for all.
Aquatic Pests (Milfoil, Zebra Mussels, and Water Chestnuts) Milfoil has choked over 200
acres of our 600-acre lake. We are participating in a Cornell University and Lake Champlain
Basin Program study releasing Acentria ephemerella (milfoil moth) to control the milfoil
naturally. However, we suspect that the sunfish (especially pumpkinseeds and yellow perch)
are eating many of our moth caterpillars. To reduce predation, keep all of the pan fish you
catch and dispose of them properly (eating them fried in beer batter works or you could bury
them on land).
We do not have Zebra Mussels or Water Chestnut yet and we ask you clean all weeds
and other organisms from your boats and trailers before launching in Lincoln Pond. All
bilge water and bait boxes should be drained and air-dried for a week. Scrape off any Zebra
Mussels and remove any plant or animal material from boats and trailers.
********************Fishing Request*****Please****************************
We are requesting a VOLUNTARY CATCH AND RELEASE OF BASS until
they are 16 inches instead of 12 inches. This will give them a few more years to eat the
pan fish before they are removed, and you can have trophy size fish next year.
Once again we are asking all fishermen to remove any pan fish that they catch.
**************************************************************************
Boaters
1. Clean you boat before entering and after leaving Lincoln Pond. We need your help in
preventing the spread of milfoil and the introduction of water chestnut and zebra
mussels. It is NYS law not to transport noxious species from one lake to another.
2. NY State Law says 5 mph within 100 feet of shore, docks, piers, rafts, floats or
anchored boats or within 500 feet of a roped off swimming area. 5 mph means no
wake. In Lincoln Pond the area between the causeway and the island, and the
narrows at the north end by the dam are less than 200 feet wide and therefore are no
wake zones.
3. Stay 100 feet from all other boaters, anchored boats, swimmers, and fishermen.
4. NY State Law says personal watercraft or “jet ski” operators must be 21 years old or
have a “Certificate of Instruction.”
Lincoln Pond/Milfoil 2002 Report
28
5. Remember there are others that do not want to hear constant motor noise all day. We
are asking recreational users, such as water skiers and jet skiers, to only operate
between the hours of 10 AM and 6 PM. This will let the fisherman fish in peace and
quiet, and late sleepers get a few extra winks.
6. Make sure your motor is in good condition and is leaking as little as possible. Two
stroke engines typically put half of their fuel into the water. Be careful when fueling
your motor. Check rubber hoses for leaks. Regularly service your motor. Use
propylene glycol instead of ethylene glycol for antifreeze.
7. Have a personal flotation device (PFD) for everyone in your boat. Children under
the age of 12 must be wearing a PFD
8. Your boat must be registered with the State of NY.
9. It is illegal to drive a boat or personal watercraft under the influence of alcohol.
Fires - Be very careful of campfires and only build them in designated protected areas.
Before you leave be sure your fire is completely out. We have had two major fires on Lincoln
Pond that have destroyed acres of wildlife habitat.
Noise - There are other campers on the lake that can hear your “music” and “laughing.” We
are glad that you are enjoying your stay; please let us enjoy ours as well. Please turn the
volume down after 10 PM.
Litter - It is illegal to dump any material into the waters of NY. Please find the appropriate
receptacle at the State Campgrounds or elsewhere.
Loons - We have a pair of loons that come back to Lincoln Pond every
year. However, they have a hard time making it through the nesting
period, which is the most vulnerable part of their life cycle. Loons usually
nest within a foot or two of the water and will leave their nest whenever
they feel threatened by waves. “We are finding that loons can nest on
busy lakes as long as they have a quiet area,” says Eric Hanson, biologist for the Vermont
Loon Recovery Project. In Lincoln Pond loons nest in Big Bay, which is the northern bay just
before the narrows, in May and June. It is best to prevent boat wake in that area during
nesting.
Tee shirts
We are developing a Lincoln Pond tee shirt to help support the cost of some of the
association’s activities especially the litter clean up and the milfoil control. If you are
interested in obtaining a tee shirt for $15, please contact Judy Swartz at [email protected].
Thank you for your help in protecting our lake.
Lincoln Pond Association
Lincoln Pond/Milfoil 2002 Report
29
For Nita’s Notes
Milfoil, Moth larvae and Sunfish
For the past two years, Robert L. Johnson (CURP), and his team have been working
with the Lincoln Pond Association, Cornell Cooperative Extension of Essex County and the
Lake Champlain Basin Program to try and find a way to control Eurasian watermilfoil,
through biological methods. There are several herbivorous insects that feed on milfoil
including the milfoil moth, the milfoil weevil, midges, Caddisflies and Mayflies. In the
laboratory both the moth and weevil have been shown to provide various levels of control for
milfoil. In larger lakes, we have seen natural declines of milfoil due to moth and/or weevil
herbivory.
In 1999, the Lake Champlain Basin Program provided a grant to see if the small
natural population of milfoil moth in Lincoln Pond could be augmented to a level that would
control a milfoil infestation of about 200 acres. In 2000 and 2001 over 60,000 moth
caterpillars were released in an attempt to establish a large enough population to control the
milfoil. Control seems to be effective when about 7 of 10 tips that are sampled have moth
larvae feeding on them.
We found that sunfish were eating our greenhouse-raised caterpillars before they had
a chance to become established and as they moved up the plant to build a new retreat/house.
This is a very disappointing finding. The milfoil is doing fine, the sunfish are doing fine, but
the moth larvae are disappearing.
Sunfish are found in large numbers in many small New York lakes. They are a warm
water fish that does well when there not a lot of larger predator fish to eat them. Sunfish
reproduce in large numbers and grow quickly. They compete for the same food supply as all
young fish thus reducing the predator fish early growth rates.
The most common types of sunfish are bluegills and pumpkinseeds. They eat insects
such as mosquitoes, dragon fly nymphs, midges, caddisflies, and now we suspect milfoil
moth larvae and milfoil weevils. Even the young of the year, one inch in size, were found
chowing down on our larval caterpillars. Bill Schock of NYS DEC says that there is not
much that can be done to control sunfish. Our best bet is more large bass in the lake to eat the
sunfish and reduce their numbers. I am sure that the fisherman would like that option. A
possible way to achieve is a catch and release program for bass.
Almost all small fish in a lake eat insects. However, there are a few species of fish
that eat fish once they grow large enough to get their mouths around the prey species. This
includes: Bass, Pike, Muskies, Walleye, Lake Trout, and Brown Trout. Rainbow and
Brookies eat insects their whole life. Lincoln Pond has Bass, Pike and Tiger Muskies. The
other predator species are found in colder waters and larger lakes. The Tiger Muskies are
self-limiting as they are territorial and will attack each other when populations become high.
The problem is that it takes predator fish a long time to grow big enough to eat other fish and
until then they must compete with the sunfish and other young fish for the same food source,
including our insects.
It looks like we will have to go back to the drawing board for new, environmentally
friendly ideas for controlling milfoil in smaller warm water lakes. We have seen that milfoil
in larger lakes might be controllable by the moth larvae and weevils, as they have more of the
large predator fish, that control sunfish populations. However, that has yet to be proven. In
Lincoln Pond/Milfoil 2002 Report
30
nature where the moth has been successful, it has always been in a larger lake or in a lake
without sunfish.
Lincoln Pond Radio Tape
Year three of the Lincoln Pond project has seen the best results so far for milfoil
control by herbivorous insects. We tried releasing the moth larvae several different ways to
see what method might have the best result. First we released them small and early, near the
bottom of the plants, thinking that they would eat a lot of plants and we might see something
the first year. But we were wrong. We never saw them again.
Then we tried releasing larger moths later in the season and up in the vegetative
portion of the plants. We could see some remnants of their eating and retreat building, but no
moths two months later. Next we released cocoons, but could not find many of them either.
Then that fall we released some dormant caterpillars in the resting phase. Amazingly, the
next spring the milfoil was growing poorly at that site.
Upon our examination we found the biomass and total tip length of milfoil was half
of that in the control area nearby. This was very heartening. We are currently thinking that
sunfish may have had something to do with the disappearance of our caterpillars. The
dormant caterpillars may have survived because they would have crawled out of the mud
when the milfoil was all bunched up on the bottom and the fish would have a harder time
finding them.
We hope to release even more of these dormant caterpillars in 2004, to further check
our hypothesis. If you would like to know more about this biological control project for
milfoil that was sponsored by the Cornell University Research Ponds and the Lake
Champlain Basin Program contact me at 518-962-4810.
Sunfish and Milfoil Moths
Small fish typically eat insects. Sunfish tend to swim in place and look for insects on
plants where they pluck them off of the stem. Bass and trout also eat insects when they are
small, but they are swimmers and move through the water to seek swimming insects.
We believe that the Lincoln Pond sunfish (which are stunted from such high
populations) are eating our moth caterpillars when we release them. Therefore the Lincoln
Pond Association is looking for an effort to take as many sunfish as possible this summer.
We are also asking fisherman to voluntarily release any bass that they catch, as the
larger bass are very good at eating sunfish and will help to get the lake into a sustainable
balance of large and small fish. An added bonus will be some very large trophy size bass in a
year or two. If you would like to know more about this biological control project for milfoil
that was sponsored by the Cornell University Research Ponds and the Lake Champlain Basin
Program contact me at 518-962-4810.
Lincoln Pond/Milfoil 2002 Report
31
Appendix LP 2002 – 6
Chart of actions
Site
A
B
C
D
Control/ Control
Release
Age
#
Control
Control
Control
Before
3/yr
average
moth #
Before
9/yr
average
weevil
#
After
average
moth #
After
average
weevil
#
Before
20.81
biomass
9/yr
0.25/yr
0.5/yr
9.5/yr
21.75/yr 21/yr
31.11
59.43
Plot EE
in D
6/14/00
1-2
instar
5,000
Plot FF
in D
6/14/00
1-2
instar
5,000
Plot B1
in B
6/22/01
3-4
instar
2,200
Plot B2
in B
6/22/01
3-4
instar
2,200
2/yr
0/yr
1/yr
1/yr
29/yr
23/yr
4/yr
3/yr
58
25
69.22
Gm D W
milfoil
After
biomass
Gm D W
milfoil
66