This summer saw some extensive billbug damage in many parts of Indiana. Obvious damage to Kentucky bluegrass in the central and northern parts of the state are not uncommon and can usually be attributed to the bluegrass billbug. However, reports of severe damage to Zoysiagrass in the Evansville area really caught my attention. Zoysiagrass is a favorite host for the hunting billbug which has been associated with damage to warm-season grasses in the southern U.S. for decades. If your turf experienced billbug damage this year, you will want to keep this in mind next spring, when treatments targeting overwintering adults, and newly hatched larvae can have the greatest impact. In southern Indiana, neonicotinoid (Merit, Arena, Meridian) pyrethroid (Talstar, Deltagrad), and anthranilic diamide (Acelepryn) insecticides may be applied as early as mid-April to achieve good preventive control. In Northern Indiana the typical timeframe for such applications will be the first week of May. Curative approaches aimed at controlling larvae in the soil tend to be much less effective because the window of opportunity is relatively short and difficult to time. However, if timed to match the presence of larvae feeding externally on the crowns, roots, and stolons of turfgrass plants (mid to late June), fair to good control can be achieved with a variety of insecticides (http://www.agry.purdue.edu/turf/report/2007/PDF/16.pdf ).
