Early Emerging Insects in Kansas: How Mild Winters Impact Pollinators and Pest Populations
Early Emerging Insects in Kansas: How Mild Winters Impact Pollinators and Pest Populations
Have you noticed anything strange this winter? For instance, the lack of cold temperatures? There have been several days this winter when temperatures have been above 70°F, and when that happens, we see the bugs come out. I remember, on a warm February day, having the window open and seeing a honeybee buzzing around our screen. Later that day, I saw moths sunbathing on the side of our house. It raised some important questions, like how they can be flying around at the first sign of warm temperatures? Is there anything for them to eat? What happens if it freezes again? And what will that mean for insect populations this year?
How Temperature and Degree-Day Accumulation Affect Insect Development
Insects are subject to the outside temperatures. They mature through a system of degree-day accumulation, meaning that when temperatures exceed a threshold, they grow and develop. This means that with just a couple of days above 50°F, the insects that have accumulated enough degree days are out and about. This could be insect eggs hatching, moths emerging from their hiding spots in the leaves, or bees leaving their hive or nest in search of food.
The Risk to Early Emerging Pollinators
Unfortunately, this could be detrimental to early-emerging insects. For example, lots of our insects have evolved alongside a particular plant. Plants also mature and grow with temperature; however, their environment can be much more variable than the cozy place where insects are hiding. If these plants aren’t active when those insects wake up from winter, they might not have a food source or reliable shelter.
Warm Winters and Increased Pest Populations
What does this mean for the populations of the insects that have woken up this early? For the specialized insects that require a specific plant, this could spell disaster for their local populations. For generalist insects with a wider host-plant range, emerging early might have a different effect. Moths can be pollinators, too; however, their larval stage is considered a pest because they feed on the foliage of various plants. Moths can overwinter as adults and are seen flying when temperatures are warm. These adults can mate and lay eggs right away. This could give pest populations a head start, as they lay thousands of eggs, whereas predators that feed on these insects lay only a fraction of that. Not just a head start; warmer winters and earlier emergence can also lead to more insect generations per year. There are even studies suggesting that, because of elevated atmospheric CO2 levels, the chemical composition of our plants can change, leading to increased herbivory by our insect pest populations.
How to Build a Climate-Resilient Landscape in Kansas
In the scientific community, it is universally accepted that anthropogenic climate change is the cause of the unusual and extreme temperature swings we are now seeing in our environment. This will continue in the future, with some years being abnormally cold and other years having a more moderate winter. The best thing we can do is prepare our landscapes to be resilient in the face of these environmental changes. Planting early flowering native spring ephemeral plants, providing habitat for our predatory insects, and reducing the “spray anything that flies” mentality we are so used to in residential landscaping.
Learn More at the Healthy Yards Expo 2026
If you are interested in how you can help vulnerable insect populations, come to the Healthy Yards Expo on April 11, 2026, at the Shawnee Civic Centre (13817 Johnson Drive, Shawnee, KS 66216). Educational speakers and local vendors will be present to answer questions about how to make your yard more environmentally resilient. Doors open at 9 am, and the first 150 patrons will receive a native tree provided by the Kansas Forestry Service. For more information, please visit johnson.k-state.edu
by Markis Hill, Horticulture Turf and Ornamental Agent, 2026