Black Turfgrass Ataenius Damage Thresholds

Since bentgrass greens in desert golf courses are vulnerable to injury from black turfgrass ataenius (BTA) beetles (Ataenius spretulus), UCR entomologists have determined when damaging populations are likely to be present and have identified an economic injury level superintendents can use to implement control measures. “The threshold levels for damaging populations of BTA on bentgrass in the low desert region of California are 5-7 larvae per square foot, which is much lower than in other parts of the country. Our results may be related to the extremely stressful conditions of the desert in midsummer and the limited ability of the plant to acquire the moisture it needs with insect-damaged roots,” said Ken Kido and Tim Paine, UCR entomologists. Depending on temperature, 2 to 3 generations of BTA occur per year in the desert. The first generation can appear as early as April or as late as July, they said. Three generations were recorded in 1994, two in 1995. Beetle larvae feed on turf roots, limiting the turf's ability to absorb water and to maintain an adequate moisture balance under stressful conditions. Stressed turf becomes wilted and dies in irregular patches. Early detection and control are vital. Selected insecticides combined with good cultural practices will minimize damage, they said. The first reports of injury to turf in California by BTA occurred in 1987 in Coachella Valley golf courses. Since then, damaging pest populations have spread to all Southern California counties. Putting Turf in a Retractable-Roof Baseball Stadium for the First Time -A Novel Challenge