What Ever Happened to BTA?
While preparing for a lecture on insect pests, it struck me what ever happened to the black turfgrass ataenius (BTA)? The first recorded turf damage caused by BTA was reported from Minnesota in 1932. In 1969 damage was reported on two golf courses in New York, followed by reports on golf courses in Ohio around 1973. Since then BTA has occurred in most states where cool season turfgrasses are grown. Although damaging on Kentucky bluegrass and creeping bentgrass, it is annual bluegrass greens and fairways that I associate BTA with.
Photograph 1: BTA damage in the annual bluegrass green surround.
The adult BTA are small shiny black beetles (3/16th of an inch long) that are found wondering around the turf in the spring. The BTA adults lay eggs which hatch producing the damaging larvae. The C-shaped grubs are very small, growing to be approximately ¼ inch long. The larvae feed on the roots of annual bluegrass producing damaging symptoms from mid-June to mid-July. If a second generation of grubs should occur damaging symptoms would appear from late August to early September.
Photograph 2: One of the original sites where BTA devasted this annual bluegrass fairway in the 1970s.
Symptoms appear as a wilting of the turf. As the grubs continue to feed the turf begins to die in irregular patches. Often symptoms are misdiagnosed as damaged or improper irrigation dispersion from sprinklers or anthracnose. The yellowish-orange irregular patches that occur in the later stages are quite similar to anthracnose injury.
Photograph 3: The BTA adult beetle present during spring.
For over thirty years, you could not manage annual bluegrass turf without being on a constant vigil for signs of BTA. Managing and controlling BTA was a popular and common topic that appeared in trade magazines and on conferences and seminars. Now you hardly ever hear a mention about it. You would think BTA was extinct.
Photograph 4: The BTA grubs that appear in mid-June through mid-July
Given that extinction is not a logical possibility, I consulted with a few entomologists. The two major reasons for a decline in complaints about BTA center around thatch management and insecticides used. BTA infest moist thatch turf especially if occurring on compacted soils. Golf course superintendents now are much more aggressive now in thatch management then they were in the 1980s and 1990s. This has resulted in a less favorable environment for BTA to cause injury.
Photograph 5: BTA grub present at the thatch/soil interface. BTA inhabit areas of high thatch/organic matter areas.
The second reason for the apparent decline is that BTA is susceptible to many of the insecticides - especially Acelepyrn – that is being used for season-long caterpillar control on the greens and surrounds.
In essence through good cultural practices and the advent of new insecticide chemistry we have taken a serious pest and reduced it to an afterthought. Too bad we can’t do that to the majority of turfgrass pests.
About the author
Dr. Karl Danneberger is a professor of Turfgrass Science at The Ohio State University. Dr. Danneberger's contact information can be found here. You may also follow Dr. Danneberger on Twitter: