Field efficacy of novaluron for control of Colorado potato beetle (Coleoptera: Chrysomelidae) on potato

Field trials were conducted in 2003 and 2004 to assess the effectiveness of novaluron (Rimon 10EC), a benzoylphenyl urea chitin synthesis inhibitor, for Colorado potato beetle, Leptinotarsa decemlineata (Say), management on potato. Foliar applications of novaluron did not significantly reduce numbers of L. decemlineata adults, egg masses, or first instar larvae, but second–fourth instars were greatly suppressed. Although an application rate of 12.5 g AI ha−1 provided unsatisfactory protection, rates of 25 and 50 g AI ha−1 proved effective when applied 2 days after second instars were first observed on plants. These rates were much less effective when applied 2 days after observance of egg masses. At 50 g AI ha−1, novaluron provided excellent, prolonged protection, whether applied twice a season, or once in alternation with imidacloprid. Defoliation was minimized, resulting in yields 3.8–5.2 times greater than those harvested from control plots. The results suggest that novaluron could be a valuable tool in future L. decemlineata management programs.