Issue 11, July 28, 2014

Japanese Beetle

Adult Japanese beetles do not appear to be very numerous this year as predicted from the deeply frozen soils in the northern half of Illinois last winter, and the dry soils in non-irrigated turf during the second half of the last two summers. It is unlikely that insecticide applications to protect trees from defoliation will be needed in most areas of the state.

Japanese beetle adults and damage to grape leaves.

This also reduces the need for preventative white grub applications. The low number of adult beetles to lay eggs coupled with the timely rains that we continue to receive throughout the state make it unlikely that Japanese beetle white grub infestations will be large and numerous. Japanese beetle adults are attracted to moist soils and green grass to lay their eggs, resulting in their concentrating egg-laying in irrigated turf in normal summers. This year, the frequent rains have caused non-irrigated areas to be green with soft, moist soil as well. As a result, the beetles lay their eggs over large areas with few areas getting enough egg-laying to cause damaging white grub numbers. There are likely to be some spotty infestations that can be identified and treated in August and September as they become apparent. (Phil Nixon)

Phil Nixon

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