Posted on April 19, 2025 by Lawn Doctor
Billbugs are notorious for causing yellow and patchy lawns, but a few strategies can evict these pests and restore your lawn to its luscious state. Targeted pest control and turf care methods can eliminate and prevent billbug infestations while strengthening your lawn.
Billbugs are turf-feeding insects that belong to the weevil or snout-beetle family. Adult billbugs range from 0.25 to 0.5 inches long and may be gray, black or brown. They have wings but rarely fly, instead crawling significant distances. Species have slight physical variations, but they’re generally recognizable by their distinctively curved bills or beaks.
Billbug species have an annual life cycle during which they produce one generation. Understanding the life cycle phases provides insight into the ideal billbug treatment and prevention measures:
While billbug species share many traits, certain types dominate, depending on the area and its climate. Each species follows a similar life cycle, but regional differences in climate and turfgrass influence their behavior, timing and preferred habitat.
This species is most common in northern climates and favors Kentucky bluegrass. Adults are often light brown and emerge in spring when temperatures increase.
More prevalent in the southeastern United States and other warm regions, hunting billbugs prefer warm-season grasses, such as zoysia and Bermuda. Adults are darker and more active at night.
Native to desert regions, Phoenix billbugs feed on turf types adapted to arid environments. Activity peaks during the cooler seasons in the Southwest.
This species is more common in high-elevation and cool-climate areas and prefers fescues and other cool-season grasses.
Certain factors increase the risk of billbug infestations by creating ideal conditions for adults and larvae to thrive. Some conditions are unavoidable, such as warmer spring temperatures that signal the life cycle’s restart.
Dense thatch layers protect larvae and encourage them to thrive. Stressed lawns may result in weaker root systems that are more vulnerable to billbug larvae damage, likewise providing easier access to food and creating ideal survival conditions. Poor lawn care practices that contribute to lawn stress include:
Symptoms of billbug infestations often mimic other turf issues and make them easy to miss. Identifying the signs promptly and accurately allows you to take action sooner and minimize billbug lawn damage.
In the early stages of billbug infestations, affected turf may appear yellow, brown or thin, resembling damage from heat or drought stress. Unlike drought-damaged turf, however, billbug-affected turf often comes out easily when tugged on since the damage results from larval feeding in the roots.
Adult billbugs feed on grass blades during the spring and early summer, leaving behind small notches or chewed edges in the soil. A cutting of grass may reveal a hollow or chewed stem or sometimes larvae inside the crown and stem tissue.
Turf inspection may also show larvae excrement, also called frass, which looks like sawdust. Larvae leave frass inside grass stems and in thatch layers.
In spring and fall, adult billbugs may appear crawling across sidewalks or driveways.
Billbugs affect turf above and below toil, with the severity of damage depending on the population size and the lawn’s overall health.
Billbug feeding creates patchy areas of brown or yellow turf that may disrupt the lawn’s appearance and expand if larvae continue feeding. Turfgrass may fail to recover if larvae have damaged roots beyond repair.
Root damage interferes with the turf’s ability to absorb water and nutrients, gradually weakening it and increasing susceptibility to weeds, disease and other pests. Weakened turf also has more difficulty recovering from foot traffic, drought and other environmental challenges.
Severe infestations may require lawn restoration with overseeding and partial to full sod replacement. Additional treatments, such as aeration and fertilization, may also be necessary to restore lawn health and resilience. Depending on the size of the affected area, this can be a time-consuming and costly process.
Billbug control involves a combination of targeting methods and timing to maximize the effects.
Beneficial nematodes are microscopic roundworms that prey on billbug larvae and other soil-dwelling insects, often yielding noticeable results within a few days. These are best applied after the adults lay eggs and during peak larvae activity. Products containing certain kinds of fungus or milky spore also eliminate adult and larval billbugs.
Chemical controls are effective as targeted treatments and preventative measures. Preventative insecticides contain imidacloprid, bifenthrin and other active ingredients that function as systemic treatments. They absorb into the plant and affect larvae that feed on stems and roots without impacting the plant itself. Other kinds of insecticides target adult billbugs to prevent them from laying another generation of eggs.
Healthy lawns are naturally pest-resistant, and preventative measures often function as a way to combat current infestations and prevent recurrences. Try these preventative strategies:
Lawn Doctor offers professional pest control services to boost your lawn’s resilience and appeal. Contact us to learn more about our targeted billbug control treatments today.
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