Published online by Cambridge University Press: 31 May 2012
Mean durations (±S.D.) of zebra caterpillar larvae, Ceramica picta (Harris), stadia 1 to 6 were 3.5 ± 1.0, 2.9 ± 1.6, 3.3 ± 1.2, 3.0 ± 1.4, 3.4 ± 1.3, and 7.2 ± 1.1 days when fed sugarbeet foliage and reared at 27 °C. Mean lengths and weights of caterpillar larvae are presented for each day of development. Mean male pupal weight was 333.5 ± 34.4 mg and mean female pupal weight was 362.9 ± 53.0 mg. Fecundity is correlated with pupal weight. Foliage consumption increases in proportion to larval age, weight, and length. Mean total foliage consumption for instars 1 to 6 was 0.55 ± 0.27, 1.49 ± 0.82, 4.61 ± 2.98, 14.4 ± 8.50, 40.32 ± 14.55, and 210.88 ± 54.52 cm2. A method to estimate economic injury levels for zebra caterpillar on sugarbeet is discussed.