Date of this Version
PROCEEDINGS OF THE NORTH AMERICAN CRANE WORKSHOP 14:81-88
Damage to planted corn seed by cranes has the potential to cause great economic loss in areas where both intersect. In 2000 the International Crane Foundation (ICF) tested limonene (LIM), methyl anthranilate (MA), and 9,10-anthraquinone (AQ) as possible replacements for the insecticides lindane and diazinon that had been used as deterrents to cranes damaging corn seed and seedlings. LIM, MA, and AQ lowered germination rates (down to 85, 90, and 92%, respectively) as compared to a germination rate of 96% in untreated corn. A 1.0% solution of AQ was effective as a crane deterrent, while LIM and MA were not. Both LIM and MA metabolized in the soil too quickly to be effective during the entire period when corn seedlings were vulnerable to crane herbivory. In 2001, a 0.5% concentration of AQ in 2 different soils (sand and organic) was tested in 2 different time periods (trial 1, 15 May to 14 June; trial 2, 26 June to 7 July 2). The concentration of AQ did not degrade to below effective levels in either soil type or in either time period. In all trials, AQ concentration of 0.5% prevented crane herbivory. Crane response to AQ-treated corn was to continue foraging in fields without damaging the planted crop. We believe AQ is an effective chemical deterrent and will prove useful for preventing crane damage to planted corn.