Figure 1. White Grub in pasture sod. Photo by Pete Bauman.
Spring is arriving throughout South Dakota and it signals the return of insects to the landscape. As the snow melts, it is a time when many tasks such as calving, pasture management, and fence maintenance begin in earnest. With many pressing needs to tend to, many ranchers may not find the time to consider the role insects play on their ranch.
Insect Communities & Rangeland Health
Insects, in general, may offer more indication of rangeland health than any other type of organism. They serve as key building blocks that other organisms depend on. The insect community present in rangelands can be complex, and most people find identification of all but the most common insects difficult. Consequently, other species are generally utilized to help interpret the condition of rangelands. For example, changes in grassland bird abundance or diversity are often used as a general indicator of rangeland health. Birds are relatively easy to see and count; thus observing grassland birds has become a powerful tool for many ranchers to gauge their range condition. However, for most grassland birds to raise a successful clutch they must provide their hatchlings with insects, or the young themselves must forage for insects on their own to meet their nutritional and developmental needs. This reality points to the critical role of insects in overall grassland ecology.
Figure 2. Dung beetles on manure pat. Photo by Pete Bauman.
Furthermore, the beneficial insect communities that are present in rangeland are dependent on healthy and diverse functioning plant communities. For example, pollinating insects such as honey bees, butterflies, native bees, and flies rely on the presence of flowering plants for nectar. Healthy and vigorous plant communities are maintained in rangeland primarily through healthy grazing systems that consider soil health and precisely targeted chemical inputs. Healthy rangelands that offer the greatest profit potential are thus maintained through a holistic, or integrated, approach that considers all natural resources, including vegetation, insects, birds, soils, water, etc. and utilizes more than one approach at reducing pest populations.
Maintaining Healthy Pastures
While maintaining healthy pastures may make sense on paper, reality can unfortunately create some issues along the way. Grazing programs can be well intentioned but poorly implemented, leading to poor pasture health, poor soil health, and reduced plant vigor. Unhealthy plant communities can be subject to invasion by undesirable plants including noxious weeds which require a holistic or integrated vegetation management plan to achieve lasting improvements. Additionally, insect pest populations also require an integrated approach that may incorporate either biological control or appropriately targeted insecticide management. Internal or external livestock parasites may lead to any number of topical or dietary treatments. In all cases, there may be adverse impacts to desirable or non-target insect communities. There may also be negative relationships between the use of various topical treatments for internal and external livestock parasites and non-target insect communities.
Figure 3. Dakota Skipper butterfly. Photo by Bryan Reynolds.
Pasture Bugs n’ Grubs Spring Road Show
Recognizing these challenges, the South Dakota Grassland Coalition in partnership with SDSU Extension specialists and researchers, NRCS field staff, and other experts from partner organizations hosted an inaugural Pasture Bugs n’ Grubs spring road show with stops in Watertown, Chamberlain/Oacoma, and Rapid City on April 25, 26, and 27, 2017. The road show was designed to allow producers from across the state to hear experts present on key insect-related issues affecting farms and ranches. Road show topics included: dung beetles and manure decomposition, white grub concerns, the role of pollinators in pastures, status of South Dakota biological control programs, livestock parasites, and alternatives to chemical control in animal and range health. Pat Guptill, a rancher from Quinn, South Dakota and the 2013 South Dakota Leopold Conservation Award Winner wrapped up each day with his unique perspective for “Putting it all together on the ranch.”
For more information on various pasture insect and parasite issues, visit recent iGrow articles:
Dung Beetles & Fly Control
Pollinators & Pasture Health
- Understanding the Critical Role of Broadleaf Pollinator Plants in Pastures
- Diversity and Partnerships are Keys to Preventing Endangered Species Impacts
- SDDA Sensitive Site Registry: Protecting sensitive areas from chemical drift
- Cows & Butterflies: Why Private Grazing Lands Matter in a Changing Landscape
- Sustainable Beef Starts With Grass
- Common Pollinators in South Dakota: An identification guide
- How Did South Dakota Honey Bees Fare Last Year?