Biological aspects of Tiracola grandirena (Herrich-Schäffer, 1868) (Lepidoptera: Noctuidae): a polyphagous armyworm

Abstract

We studied the biology of Tiracola grandirena(Herrich-Schäffer, 1868) (Lepidoptera: Noctuidae: Hadeninae) at 25 ± 1 °C, 70 ± 10% RH and 14 hours of photo phase. Three experiments, using 150 larvae each, were conducted for the larval stage. In the first, used to assess the duration and survival of all stages, insects were reared individually and fed an artificial diet (Grenee). In the second, individuals were also reared separately, but were fed leaves of 10 plants from different families. In the third, the larvae were not individualised, the food plants were rotated such as to provide three plant species every 48 hours. In the first experiment, the viability of the eggs, larvae, pupae and prepupae was 91.9, 94.7, 32.49 and 43.5%, respectively. The average duration of the egg, larvae, prepupae, pupae and adult were 6.0, 25.3, 25.7, 21.4 and 12.7 days, respectively. The prolonged prepupal period indicates that T. grandirena can develop larval (prepupal) diapause. The results of the experiments with different host plants showed that T. grandirena is polyphagous at species, population and individual level.