sites were used each year. Numbers of adult BTA in the respective plots were monitored with pitfall traps or soap drenches, and densities of first-generation BTA grubs were determined from soil samples taken in early summer.

Two organic fertilizers, Nature Safe and Milorganite, were associated with somewhat higher BTA populations. In 2000, untreated plots had an average of 98 grubs per square foot, as compared to 148 and 140 with Nature Safe and Milorganite, respectively. In 2001, average grub densities were 47 per square foot for untreated plots, 107 per square foot for plots treated with Nature Safe and 117 per square foot for plots with Milorganite. In both years, the plots treated with Nature Safe and Milorganite had significantly larger numbers of grubs. Adult densities, too, tended to be higher, especially in the plots that had been treated with Milorganite. In contrast, no increase was associated with use of Sustane or urea.

Many superintendents prefer organic fertilizers because they do not burn, have slow release and resist leaching. Organics contain sulfur, iron and trace elements that may enhance plant metabolism and disease resistance. Although my results suggest some organic fertilizers may be a risk factor for BTA, the risk probably does not
outweigh the benefits that such fertilizers provide. BTA is a sporadic problem, and many golf courses never see damaging infestations. Nevertheless, superintendents who use organics should be alert for BTA and consider preventive management if the beetles and grubs
are abundant.

Acknowledgments

This work was supported in part by a grant from the USGA. I am grateful to former superintendent Bob Mason and the staff at Pendleton Country Club, Pendleton County, Ky., for their cooperation.

References

1. Niemczyk, H.D., and D.J. Shetlar. 2000. Destructive turf insects. 2nd ed. HDN Books, Wooster, Ohio.

2. Potter, D.A. 1998. Destructive turfgrass insects. Biology, diagnosis, and control. Ann Arbor Press, Chelsea, Mich.

3. Vittum, P.J., M.G. Villani and H. Tashiro. 1999. Turfgrass insects of the United States and Canada. 2nd ed. Cornell University Press, Ithaca, N.Y.

4. Wegner, G.S., and H.D. Niemczyk. 1981. Bionomics and phenology of Ataenius spretulus. Annals of the Entomological Society of America 74(4):374-384.