2000 PROGRESS REPORT

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Biological Control of Noxious Weeds at the U.S. Air Force Academy, Colorado.

2000 Progress Report

by

Dr. G. J. Michels, Jr., D.A. Owings, D. C. Dowdy, and B.L.Castleberry Texas Agricultural Experiment Station, Bushland, Texas 79118

Introduction Our project’s goal is to reduce the existing populations and control the spread of selected state- and federal-listed noxious weeds. The project will take place on the US Air Force Academy (USAFA) and the Monument Fire Center (MFC). The objectives of the research are to 1. Develop and implement procedures and sampling methods to assess the present state of any existing biological controls on the selected species at USAFA and MFC; 2. Monitor abiotic and biotic factors which may be peculiar to USAFA and/or MFC through field data collection and assess the impact of these factors on establishment of natural enemies; 3. Conduct greenhouse studies to determine the seed bank and conduct herbicide/natural enemy compatibility tests to help make decisions for IPM strategies. Use the greenhouse populations of the natural enemies for additional releases; 4. Release several species of natural enemies using release cages and open field releases. Use GPS for mapping establishment and spread of natural enemies as well as the weed infestation. Monitor and redistribute established populations. Phase I of this three-phase project will consist of surveying for noxious weeds, collecting and releasing biocontrol agents, and sampling for establishment. To carry out this project, the Air Force Academy and its neighbor, the US Forest Service, will team up with biological control experts from the Texas Agricultural Experiment Station. The Texas Agricultural Experiment Station will provide expertise, supplies, and biocontrol agents. In addition, they will conduct the surveys, release the biocontrol agents, and monitor for establishment. The US Forest Service will provide volunteers to manually control weeds and assist the Texas Agricultural Experiment Station staff. In any biological control program, there is a three-phase approach to ensure a sound program that achieves the desired reduction in the pest species targeted for control:

1. Phase One consists of collection and release of biocontrol agents

and sampling for establishment. 2. Phase Two takes biocontrol agents that are established in Phase

One, and redistributes them into areas where they are not yet established in order to engender high populations of the agents.

3. Phase Three consists of an ecological and economic analysis of the program in terms of how the biocontrol program impacted the pest and the benefits accruing to their establishment in light of standard control practices. In general, each phase covers three years.

Effects of the control program are expected in the third year, however, all results are very dependent on climatic conditions, especially temperature and rainfall. Severity of winter conditions will also influence establishment of the insects. It cannot be said that control of a given weed species will take place on a particular date, however, we expect a gradual weakening of weed infestations followed by recovery of the affected areas over the next five years. Knapweed is an aggressive perennial weed, has little nutritive value and is an invasive competitor, decreasing forage production as much as 60 to 90 percent. Spotted knapweed is one of the most important rangeland weeds in western North America with approximately 287 million ha infested. Canada thistle is an aggressive dioecious perennial, which grows in patches and has a diverse habitat. Because of its random distribution, it is difficult to determine complete losses, but is considered to be a noxious weed in at least 34 states in the United States. Leafy spurge is an aggressive long-lived and deep-rooted perennial. It infests over three million acres in 29 states and has cost millions of dollars in control cost efforts and loss of forage productivity. Leafy spurge degrades wildlife habitat, decreases plant diversity, competes with native plant species, and reduces land values. This report describes the progress during 2000. Several organizations have cooperated with this program, including the Colorado Department of Agriculture, Pennsylvania Department of Agriculture, USDA-APHIS Spokane WA, and U.S. Fish and Wildlife. Chronology April In cooperation with Major John Putnam, USAFA, several potential release sites were located (Fig. 1). One spotted knapweed site was located near Monument Creek (Fig. 1a). Soil samples and seedheads were collected and brought back to Bushland, TX for further analysis. A caged release of the Metzneria paucipunctella, the spotted knapweed seed head moth, was made. M. paucipunctella were provided by Steve Miller (USDA-APHIS Spokane, WA) (Table 1, Fig. 2). Canada thistle sites were located at 2 locations, referred to as Water Tank (Fig. 1b) and Ice Lake Road (Fig. 1c). Musk thistle was also noted at Ice Lake Road site.

May Monument Creek site was georeferenced. Another Canada thistle site, referred to as Eagle Peak, was located by Maj. Putnam (Fig.1d). All three Canada thistle sites were georeferenced and density and height counts were taken (Table 2). Rhinocyllus conicus, a thistle seed head weevil, was determined to already be established at Ice Lake Road site on Canada thistle and musk thistle. June The first release of Trichosirocalus horridus, the thistle crown weevil, was made at the Ice Lake Road site (provided by Kent Mowrer Colorado Dept. of Agric.) (Table 1,Fig 3). Three leafy spurge sites were located by Maj. Putnam, referred to as Ferl site (Fig.1e), Douglas school site (Fig.1f), and Deadmans Trail site (Fig.1g). Apthona sp. were collected at Parker, Colorado for release at the three sites. Apthona nigriscutis, Apthona lacertosa and Apthona czwalinae were released at these 3 sites the same day (Table 1,Figs. 4-6). All sites were georeferenced. Height and density data were collected at each site (Table 2). The bindweed mite, Aceria malherbae, was released on bindweed located at the Ferl site (Table 1,Fig 4). July A leafy spurge site at Monument Fire Center was located by Steve Tapio of the U.S. Forest Service. He also located a knapweed site (mostly diffuse knapweed). These sites will be georeferenced and data collected from them in Spring 2001. Another Canada thistle site was located near the first Ice Lake Road site, referred to as Ice Lake Road II (Fig.1h). Larinus planus, the Canada thistle bud weevil, was released at this site along with Cassida rubiginosa, a thistle shield beetle, both provided by Jim Stimmel of the Pennsylvania Dept. of Agric.(Fig. 7). Density and height data was collected (Table 2). Larinus minutus, the lesser knapweed flower weevil, provided by Fred Stahl of the Colorado Dept. of Agric. was released at the Monument Creek site (Table1). August Checked the leafy spurge sites for insect colonization. Adult Apthona sp. were observed at each location. Soil samples were collected at each site for seed bank determination studies (Table 3a – 3c). November Spotted knapweed seedheads were collected for dissection to determine what bioagents, including L.minutus or M. paucipunctella were present and the percentage of infested heads (Table 4).

Fig. 1. The location of 8 noxious weed and potential biocontrol release sites located at the Air Force Academy (a-h) in 2000.

h

c

d

f

g

b

a

e

USAFA Biological Control of Weeds Release Sites 2000

Common Name Species Agency2000 Releases in BOLD Date Site1 Number Total

Lesser knapweed flower weevil Larinus minutus Colo.Dept. Of Agric 07/15/00 1 150 150UV knapweed seed head fly Urophora quadrifasciata determined to be already established at this siteBanded gall fly Urophora affinis determined to be already established at this siteSpotted knapweed seed head moth Metzneria paucipunctella USDA/APHIS, WA 04/20/00 1 2 72002

Thistle-feeding shield beetle Cassida rubiginosa Penn.Dept.of Agric. 07/15/00 3 1 75Canada thistle bud weevil Larinus planus Penn.Dept.of Agric. 07/15/00 3 1 150

Rosette weevil Trichosirocalus horridus Colo.Dept.of Agric. 06/21/00 2 75 75

Bindweed gall mite Aceria malherbae Tx Agric. Exp. Sta.,TX 06/28/00 7 1 13

Black dot leafy spurge flea beetle Apthona nigriscutis Colo.Dept. Of Agric 06/28/00 6,7,8 2 20004

Brown-legged leafy spurge flea beet Apthona lacertosa Colo.Dept. Of Agric 06/28/00 6,7,8 2 20004

Black leafy spurge flea beetle Apthona czwalinae Colo.Dept. Of Agric 06/28/00 6,7,8 2 20004

1Sites: 1-Monument Creek; 2-Ice lake Road; 3-Ice Lake Road II; 4-Eagles Peak; 5-Water Tank; 6-Dead man's trail; 7-Ferl; 8-Douglas School2Released in screened cages containing 3600 seedheads/cage (approx. 2808 larvae/cage; 78% infestation).3Release consisted of twenty mite-infested bindweed sprigs placed at the field bindweed site. Each sprig housed approximately 100 mites for a sum of approximately 2000 mites.4All three Apthona sp . were collected and bagged together in groups of approx. 1000 mixed adults

Musk (Carduus nutans )

Field Bindweed (Convolvulus arvensis )

Leafy Spurge (Euphorbia esula )

Table 1. Summary of Insects Released for Biological Control of Weeds at the United States Air Force Academy, 2000.Release

Spotted knapweed (Centaurea maculosa )

Canada thistle (Cirsium arvense )

Spotted knapweed density and height

Fig. 1a. Maps of the spotted knapweed infestation, density and height at the Monument Creek release site 2000.

Canada thistle density and height

Fig. 1b. Maps of the Canada thistle and musk thistle infestation, as well as Canada thistle density and height at the Water Tank site 2000.

Canada thistle and musk density and height

Fig. 1c. Maps of Canada thistle and musk thistle infestation, density, and height at Ice Lake Road release site 2000.

Canada thistle and musk density and height

Fig. 1d. Maps of Canada thistle and musk thistle infestation, density and height at Eagle Peak release site 2000.

Leafy spurge density and height

Fig. 1e. Maps of leafy spurge infestation, density and height at Ferl release site 2000.


Fig. 1f. Maps of leafy spurge infestation, density, and height at Douglas School release site 2000.


Fig. 1g. Maps of leafy spurge infestation, density, and height at Deadman’s trail release site 2000.

Canada thistle density and height

Fig. 1h. Maps of Canada thistle infestation, density, and height at Ice Lake Road II release site 2000.

Table 2. Spotted Knapweed, Leafy Spurge, Musk, and Canada Thistle Densityand Height 2000

Site Target WeedSample

(n)density

(m2)height (cm)

density (m2)

height (cm)

Dead man's trail Leafy spurge 28 0 - 195 0 - 75.5 58.89 39.68Douglas school Leafy spurge 30 0 - 61.5 0 - 56 16.54 34.64Eagle Peak Canada thistle / musk 48 0 - 12 0 - 151 2.64 50.39Ferl Leafy spurge 60 0 - 29 0 - 73 4.77 20.30Ice Lake Road Canada thistle / musk 97 0 - 32 0 - 171 6.51 58.87Ice Lake Road II Canada thistle 65 0 - 36 0 - 115 8.05 67.17Monument Creek Spotted knapweed 36 0 - 25 0 - 76 6.83 37.72Water Tank Canada thistle / musk 26 0 - 90 0 - 130 21.15 88.96

Range Average

SSppootttteedd kknnaappwweeeedd

Fig. 2. A spotted knapweed site referred to as Monument Creek located at the Air Force Academy, Colorado. Metzneria paucipunctella and Larinus minutus were released at this site in 2000.

CCaannaaddaa aanndd mmuusskk tthhiissttlleess

Fig. 3. A Canada thistle and musk thistle site referred to as Ice Lake Road, located at Air Force Academy, Colorado. Trichosirocalus horridus was released on musk thistle in 2000.

LLeeaaffyy ssppuurrggee

Fig. 4. A leafy spurge site referred to as Ferl, located at Air Force Academy, Colorado. Apthona sp. were released at this site in 2000. Aceria malherbae, the bindweed mite, was released in a field bindweed infestation located near the Ferl site in 2000.

LLeeaaffyy ssppuurrggee

Fig. 5. A leafy spurge site referred to as Douglas School, located at Air Force Academy, Colorado. Apthona sp. were released at this site in 2000.

Fig. 6. A leafy spurge site referred to as Deadman’s Trail, located at Air Force Academy, Colorado. Apthona sp. were released at this location in 2000.

CCaannaaddaa tthhiissttllee

Fig. 7. A Canada thistle site referred to as Ice Lake Road II, located at Air Force Academy, Colorado. Two releases have been made at this site, Cassida rubiginosa and Larinus planus, in 2000.

Table 3a. Estimates of seed bank from USAFA soil samples in 2000.Bioagents Sampling Soilreleased date a depth

(in.)Canada thistle

Spotted knapweed

Bindweed Musk Leafy spurge

Grasses Forbs Total

M. paucipunctella 06/01/00 1 - 0.00 - - - 0.00 0.00 0.00L. minutus 07/17/00 1 - 1.00 - - - 3.67 6.00 10.67

11/20/00 1 - 0.33 - - - 0.00 0.33 0.6712/20/00 1 - 0.00 - - - 0.33 0.33 0.66

Average 0.33 1.00 1.67 3.0006/01/00 2 - 3 - 0.00 - - - 0.00 0.00 0.0007/17/00 2 - 3 - 0.67 - - - 0.33 4.00 5.0011/20/00 2 - 3 - 0.00 - - - 0.00 0.00 0.0012/20/00 2 - 3 - 0.33 - - - 0.00 0.33 0.66

Average 0.25 0.08 1.08 1.42

08/31/00 1 0.33 - - 4.67 - 2.00 4.67 11.6709/25/00 1 0.00 - - 0.00 - 4.67 14.67 19.3410/26/00 1 0.00 - - 0.00 - 0.00 0.00 0.0011/20/00 1 0.00 - - 0.00 - 0.00 0.00 0.0012/20/00 1 0.00 - - 0.00 - 0.33 3.00 3.33

Average 0.07 0.93 1.40 4.47 6.8708/31/00 2 - 3 0.00 - - 1.33 - 0.67 0.67 2.6709/25/00 2 - 3 0.00 - - 0.00 - 1.67 6.00 7.6710/26/00 2 - 3 0.00 - - 0.00 - 0.00 0.00 0.0011/20/00 2 - 3 0.00 - - 0.00 - 0.00 0.00 0.0012/20/00 2 - 3 0.00 - - 0.00 - 0.33 3.33 3.66

Average 0.00 0.27 0.53 2.00 2.80

T.horridus 08/31/00 1 0.00 - - 0.00 - 0.00 3.67 3.6709/25/00 1 0.00 - - 0.33 - 0.00 9.33 9.6610/26/00 1 0.00 - - 0.00 - 0.00 0.33 0.3311/20/00 1 0.33 - - 0.00 - 0.00 0.33 0.6612/20/00 1 0.00 - - 0.00 - 0.00 4.00 4.00

Average 0.07 0.07 0.00 3.53 3.6608/31/00 2 - 3 0.00 - - 0.00 - 0.33 6.00 6.3309/25/00 2 - 3 0.00 - - 0.00 - 1.00 9.33 10.3310/26/00 2 - 3 0.00 - - 0.00 - 0.00 0.00 0.0011/20/00 2 - 3 0.00 - - 0.00 - 0.00 0.33 0.3312/20/00 2 - 3 0.00 - - 0.33 - 0.00 2.33 2.66

Average 0.00 0.07 0.27 3.60 3.93

T.horridus 08/31/00 1 0.00 - - 0.00 - 12.00 0.33 3.4509/25/00 1 0.00 - - 0.00 - 8.00 3.67 11.6710/26/00 1 0.00 - - 0.00 - 0.00 0.00 0.0011/20/00 1 0.00 - - 0.00 - 0.00 0.33 0.3312/20/00 1 0.00 - - 0.00 - 0.00 1.33 1.33

Average 0.00 0.00 4.00 1.13 5.1308/31/00 2 - 3 0.00 - - 0.00 - 4.33 0.067 3.6909/25/00 2 - 3 0.00 - - 0.00 - 7.00 5.33 12.3310/26/00 2 - 3 0.00 - - 0.00 - 0.00 0.00 0.0011/20/00 2 - 3 0.00 - - 0.00 - 0.00 0.00 0.0012/20/00 2 - 3 0.00 - - 0.00 - 0.00 0.33 0.33

Average 0.00 0.00 2.27 1.15 3.41

Average number of plants emerged b

Ice Lake Road (musk)

Ice Lake Road

Monument Creek

Eagle Peak

Table 3b. Estimates of seed bank from USAFA soil samples in 2000.Bioagents Sampling Soilreleased date a depth

(in.) Canada thistle

Spotted knapweed


Grasses Forbs Total

A. nigriscutis 08/31/00 1 - - - - 0.00 1.67 0.00 3.22A. lacertosa 09/25/00 1 - - - - 1.00 2.33 2.67 6.00A. czwalinae 10/26/00 1 - - - - 0.00 0.00 0.00 0.00

11/20/00 1 - - - - 0.00 0.00 0.00 0.0012/20/00 1 - - - - 0.00 0.00 0.67 0.67

Average 0.20 0.80 0.67 1.6708/31/00 2 - 3 - - - - 0.00 0.00 0.67 1.6709/25/00 2 - 3 - - - - 0.67 1.67 5.00 7.3410/26/00 2 - 3 - - - - 0.00 0.00 0.00 0.0011/20/00 2 - 3 - - - - 0.00 0.00 0.00 0.0012/20/00 2 - 3 - - - - 0.00 0.00 0.00 0.00

Average 0.13 0.33 1.13 1.60


11/20/00 1 - - - - 0.00 0.67 0.00 0.6712/20/00 1 - - - - 0.00 0.00 0.00 0.00

Average 0.00 8.47 0.60 9.0708/31/00 2 - 3 - - - - 0.00 2.67 1.33 7.9509/25/00 2 - 3 - - - - 0.33 6.00 2.00 8.3310/26/00 2 - 3 - - - - 0.00 0.00 0.00 0.0011/20/00 2 - 3 - - - - 0.00 0.00 1.00 1.0012/20/00 2 - 3 - - - - 0.00 0.00 0.33 0.33

Average 0.07 1.73 0.93 2.73


11/20/00 1 - - - - 0.00 0.33 0.00 0.3312/20/00 1 - - - - 0.00 2.33 0.00 2.33

Average 0.13 4.13 0.33 4.6008/31/00 2 - 3 - - - - 0.33 1.00 0.00 4.2509/25/00 2 - 3 - - - - 0.00 3.33 0.00 3.3310/26/00 2 - 3 - - - - 0.00 0.00 0.00 0.0011/20/00 2 - 3 - - - - 0.00 0.00 0.00 0.0012/20/00 2 - 3 - - - - 0.00 0.00 0.00 0.00

Average 0.07 0.87 0.00 0.93

A. malherbae 08/31/00 1 - - 0.00 - 0.00 22.67 0.33 0.8509/25/00 1 - - 0.00 - 0.00 24.33 1.67 26.0010/26/00 1 - - 0.00 - 0.00 1.00 0.33 1.3311/20/00 1 - - 0.33 - 0.00 2.67 3.00 6.0012/20/00 1 - - 0.00 - 0.00 2.33 1.33 3.67

Average 0.07 0.00 10.60 1.33 12.0008/31/00 2 - 3 - - 0.00 - 0.00 21.00 0.33 9.8009/25/00 2 - 3 - - 0.00 - 0.00 21.33 1.33 22.6610/26/00 2 - 3 - - 0.00 - 0.00 7.33 1.33 8.6611/20/00 2 - 3 - - 0.00 - 0.00 0.67 0.33 1.0012/20/00 2 - 3 - - 0.33 - 0.00 1.00 0.33 1.67

Average 0.07 0.00 10.27 0.73 11.06

Ferl

Ferl (bindweed)


Douglas School

Deadman's Trail

Table 3c. Estimates of seed bank from USAFA soil samples in 2000.Bioagents Sampling Soilreleased date a depth

(in.) Canada thistle

Spotted knapweed


Grasses Forbs Total

L.planus 08/31/00 1 0.33 - - 0.00 - 7.33 7.67 9.01C.rubiginosa 09/25/00 1 0.00 - - 0.00 - 3.00 10.33 13.33

10/26/00 1 0.00 - - 0.00 - 0.00 0.00 0.0011/20/00 1 0.00 - - 0.00 - 0.00 0.33 0.3312/20/00 1 0.33 - - 0.00 - 0.00 3.33 3.66

Average 0.13 0.00 2.07 4.33 6.5308/31/00 2 - 3 0.00 - - 0.00 - 3.00 9.00 4.7709/25/00 2 - 3 0.00 - - 0.00 - 4.67 17.33 22.0010/26/00 2 - 3 0.00 - - 0.00 - 0.00 0.00 0.0011/20/00 2 - 3 0.00 - - 0.00 - 0.33 1.00 1.3312/20/00 2 - 3 0.00 - - 0.00 - 0.33 4.67 5.00

Average 0.00 0.00 1.67 6.40 8.07

08/31/00 1 0.33 - - 0.00 - 0.67 1.67 7.2809/25/00 1 0.00 - - 0.00 - 0.67 5.33 6.0010/26/00 1 0.00 - - 0.00 - 0.00 0.00 0.0011/20/00 1 0.00 - - 0.00 - 0.33 0.33 0.6612/20/00 1 0.00 - - 0.00 - 0.67 0.00 0.67

Average 0.07 0.00 0.47 1.47 2.0008/31/00 2 - 3 0.67 - - 0.00 - 1.00 1.00 1.8709/25/00 2 - 3 0.00 - - 0.00 - 5.00 4.67 9.6710/26/00 2 - 3 0.00 - - 0.00 - 0.00 0.00 0.0011/20/00 2 - 3 0.00 - - 0.00 - 0.00 0.00 0.0012/20/00 2 - 3 0.00 - - 0.00 - 2.00 1.33 3.33

Average 0.13 0.00 1.60 1.40 3.13

Ice Lake Road II

Water Tank


Table 4. Summary of Larvae Recovered from Spotted Knapweed Seed heads, Monument Creek Site, 2000. Species Status

total/50 average/ std. total percentseed heads seed head error 0 1 2 3 4 5 6 7 8 9 10

Urophora quadrifasciata Live 74 2.90 1.40 0.0 13 13 8 7 1 1 1 1 0 0 0Dead 8 0.31 0.16 45 2 3 0 0 0 0 0 0 0 0Total 82 0.80 0.10 58 15 11 7 1 1 1 1 0 0 0

Urophora affinis Live 5 0.20 0.12 0.0 47 2 0 1 0 0 0 0 0 0 0Dead 0 0.00 0.00 50 0 0 0 0 0 0 0 0 0 0Total 5 0.05 0.03 97 2 0 1 0 0 0 0 0 0 0

Larinus minutus Live 8 0.31 0.16 * 16 42 8 0 0 0 0 0 0 0 0 0Dead 0 0.00 0.00 50 0 0 0 0 0 0 0 0 0 0Total 8 0.08 0.03 92 8 0 0 0 0 0 0 0 0 0

1 Number of larvae in dissected seed heads.2 Seed heads containing the specified number of larvae in fifty seed head sample.* Larvae will not develop after being removed from the dissected seed head, however 5 of the 8 L.minutus had already emerged prior to dissection.

Larval density1 Emerging adults Larval frequency distribution2

Results In 2000, seven different bioagents were released at the Air Force Academy, targeting five species of noxious weeds, musk and Canada thistle, spotted knapweed, leafy spurge, and field bindweed. Larinus minutus larvae were recovered from dissected spotted knapweed seed heads several months after the release. Cassida rubiginosa damage was noted one month after the release at Ice Lake Road II (Fig.8). The data collection and mapping that has been done is the baseline necessary to track reductions in weed densities and height, the spread of bioagents, possible spread or reduction of weed infestation areas, and the impact of the bioagents on the weed populations. The seedbank research will be continued until no further plant growth is observed. This research will aid in identifying how much time may be necessary to observe dramatic reductions of the weed populations. A large seedbank will require more time before the impact of bioagents on a weed population may be recognized. Table 5 shows a summary of the average number of noxious weeds emerged at Air Force Academy compared to samples taken from Fort Carson, Colorado in 1999. The average number of the targeted weeds at Fort Carson are higher than those at

the Air Force Academy. This would suggest that the weed populations have been established at Fort Carson longer than those at the Air Force Academy. This will benefit the biological control program at the Air Force Academy and will allow biocontrol agents to start having an impact on these newer weed populations before they become more dense and widespread.

Fig. 8. Photo of Canada thistle showing feeding damage from the leaf-feeding shield beetle, Cassida rubiginosa at Ice Lake Road II release site, Air Force Academy, 2000. 2001 Field research will continue at Air Force Academy. All sites will be monitored for establishment of bioagents and data recorded regularly for plant density, height, spread and/or reduction, and damage. Additional releases of bioagents will continue. New insects scheduled to be released in 2001 include: the Canada thistle stem weevil, Ceutorynchus litura, the thistle stem gall fly, Urophora cardui, the bronze knapweed root-borer, Sphenoptera jugoslavica, and the knapweed root weevil, Cyphocleonus achates., depending on availability of insects. GPS

Table 5. Comparison of seedbank averages from Air Force Academy andFort Carson, Colorado.Site1

1 2-3

Monument Creek 0.33 0.25Cantonment I 0.56 0.59Cantonment II 0.71 0.39

ARA 1.08 0.45Reservoir 1.67 2.00Duckpond 0.67 0.67Gate 5 0.45 0.11

Wildlife Reserve 0.83Gate 5 0.11

Eagle Peak 0.07Ice Lake Road 0.07Ice Lake Road II 0.13Water Tank 0.07 0.13

Eagle Peak 0.93 0.27Ice Lake Road 0.07 0.07

1Sites in black are located at Air Force Academy, Colorado. Sites in red arelocated at Fort Carson, Colorado.

soil depth (in.)Target weed

Musk

Canada thistle

Spotted knapweed

mapping will be conducted to determine possible spread of established or newly colonized biocontrol agents as well as spread/reduction of the weed infestations. A biocontrol program will be initiated at Monument Fire Center in cooperation with the U.S. Forest Service and new weed infestation areas will be mapped and data collected. Insect releases will be made at the new sites which will be monitored and recorded.

Documents

2000 PROGRESS REPORT