Bio-Control of Leafy Spurge

PROJECT BACKGROUND
This land has been a family operation for many years. Through this land we have raised Black Angus cattle and grazed them on the 640 acres of which have been taken over by Leafy Spurge. Because of this noxious weed, we have had to decrease our cow herd number by approximately 50%. We grazed this land year round so there were no sustainable practices in place.

The leaf spurge plant has been around for years and as a child I remember spraying this plant but never being able to handle on it. Aerial spraying, ground spraying and Tordon Beads were some methods we used. We sprayed using 2.4D and Tordon hoping to get rid of or at least contain this noxious weed from spreading.

PROJECT DESCRIPTION AND RESULTS
The use of different management and grazing practices to control a noxious weed to aid in putting nature back in balance is what I’m looking at. They spray program has not proven effective for us. The cost of using chemicals to control leafy spurge is not feasible. We would be spending more money in chemical than what the land itself is worth. The leafy spurge plant has taken over about 80% of the 640 acres. In 1995 a chemical plot was set aside with different rates of chemical used. This plot was inside a 40-acre area of which bio-control is intended to be used to see if we can use a combination of management practices. In formulating this plan of action we decided to include the bio-control component by using a selection of species according to the criteria needed to establish the insects on the land. The use of the insects has been accepted throughout this area as a whole with the landowners.

Due to a rough terrain and not having very good access to certain areas with chemicals, the bio-control is the best solution to getting the leafy spurge under control. This will reduce the chance of chemical reaching the dam which is my only source of water, and would eliminate the loss of the trees and brush on this land as well. My goal is to work with Badlands Leafy Spurge Control Program to come into this section with the bio-control along with the chemical to see what can be done to help in controlling Leafy Spurge. Control areas will be set up in different areas of this section using a species called Nitriscutis. In these control areas we will use different numbers 100, 200 and 500 per one and two acre grids to see which area we will do the controlling faster. The 500 insects per 2.5 acre grids will also fall in the chemical plot that was set aside. Along with these two management practices I will also be using sheep to graze in at least two of the control areas to see if their assistance will be beneficial as well. These control areas have 100 insects per acre and 500 insects per 2.5 acre grids. Hoping that with all of this working together the stress put on the plant will be too much for its survival and control will happen sooner.

1996 brought us to a close as far as getting all of our components together to see if the project will progress as expected. Six hundred sheep including lambs were used in the control areas for three weeks. The choice of herding them by day and fencing them in a night was used. They grazed an average of 12 hours per day so fencing them at night meant we were able to leave the fence in one spot longer than if we fenced them in all the time. Throughout the three-week process the fence was moved twice. Water was hauled to them two to three times a day depending on the temperature. Three portable tanks were set up and the three of them together could hold 500 gallons of water. Many times it took two trips per watering to get them all taken care of and each trip was a 15-mile round trip.

Through this process we will be looking at reducing the spread of the leafy spurge through the seeds as well as opening up the area so the grasses have a chance of competing again. Also, will the use of Tordon inside our control area affect the rise of the population of the insects. Using a combination of management practices we hope to show this may be our best bet in taking control of this noxious weed. The stress put on the plant with these combinations can only decrease the density and flowering of the plant. As the spurge canopy has been decreased thru grazing, chemical and bio-control, we have noticed the cattle have been able to graze throughout the entire pasture. We are hoping to find our insects spreading faster due to all this grazing activity going on around them.

1996 by being able to put the sheep in two of the control areas remember on e of which also has a chemical plot we found that the sheep nor the chemical had a negative affect on the insects. The sheep were grazing when the insects had reached their peak season and we were able to find insects at a good count so we knew they had enough food to survive on. The chemical had been sprayed at a time earlier in the season when it wouldn’t hurt them also. This was done when the insects hadn’t emerged yet. We had hoped for results like this of still finding the insect population along with the use of the other management practices. The insect population has grown from the initial release year of 1995 and I have been able to see depression in areas of releases. This depression consists of reduction of plant density and flowering to no plants, in a five to ten foot diameter of the release site. To see the native grasses return after such a short time has given us hope as to putting nature back in balance and hoping to have the Leafy Spurge plant considered a part of the plant species but controllable. Our next two years will be critical as we will find out that putting it all together will help in the reduction of the leafy spurge and how fast we will finally be able to say the acreage of spurge has decreased. Our goal is to have less than 40% spurge in this section in the next 10 years and to have a collection on my land like the one that took place this past summer in this area. More than one million insects were collected in eastern Golden Valley western Billings counties to redistribute throughout southwest North Dakota.

OUTREACH
We have had some tours of this area in the summers of 1995 and 1996 which included about 45 people, who were landowners, land managers and whoever else interested in controlling leafy spurge. In the fall of 1996 a range tour of about 30 people attended and what we discussed were the different practices we were using along with the grazing technique to show that we had a working project which was put together through knowledge, patience and hard work. Enclosed in a previous report were pictures and explanations of the procedures taken to show progress with this project.

There have been newspaper articles written about the project and education programs have been put on by Dan Duerre and Connie O’Brien in aiding people to get started in controlling Leafy Spurge. They have been invited to annual meetings to discuss the success of the project and asked to sit on a question and answer panel.

Due to the help of USDA-ARS station in Sidney, Montana we were able to get our control areas off the ground. They helped us make it a reality by furnishing us with the insects needed for this project.

Also USDA-ARS in Bismarck, North Dakota furnished us with some soil maps showing soil types along with elevation to help us make some analysis on our release sites.

Help with funding form the SARE grant has been beneficial to me so I was able to get a management plan in working order. With this I give a big Thank You!

The help of the Golden Valley County Extension Agent, Dan Duerre, and the field technician, Connie O’Brien, that was hired we have been able to work with several different practices to aid in the control of Leafy Spurge. We have learned through all their efforts that to establish success there are many things that need to take into effect. These include the criteria needed for each species to survive and when each species will emerge so the monitoring of the sites can take place. This will be a crucial part in the continued success of a project like this. We have released several different species of insects on this land. They are Nigriscutis, Cyparissiae, Czwalinae, and Flava. Using the different species we have been able to cover the different types of terrain this land has. High on the hill tops to the creek’s bottoms.