Population Parameters and Feeding Preference of Spodoptera litura (Lepidoptera: Noctuidae) on Different Asparagus officinalis Tissues

SIMPLE SUMMARY: The population parameters and feeding preference of Spodoptera litura on asparagus are unclear. We studied the population parameters and feeding preference of S. litura on asparagus stems and leaves. The results showed that S. litura could complete growth and development on both stems and leaves of asparagus. The developmental duration of larvae on stems was significantly shorter than that on leaves. The survival rate, the intrinsic rate of increase, and the finite rate of increase of S. litura fed on stems were higher than those fed on leaves. Therefore, asparagus stems were more suitable for its population growth. However, S. litura larvae (except for the 6th instar at 2.5 h) did not prefer to choose stems that were more conducive to their population growth. The 3rd and 5th instar larvae preferred asparagus leaves. There was no significant difference in feeding preference on stems and leaves at the age of 1, 2, 4, and 6 (except 2.5 h). Thus, we found that this pest was harmful both on asparagus stems and leaves. In the field, we will focus on stems and leaves in early prevention of this pest. ABSTRACT: Spodoptera litura is an important pest that seriously affects Asparagus officinalis production. To clarify the population characteristics and feeding preference of S. litura on different asparagus tissues, asparagus stems and leaves were selected as the research objects, related studies were conducted by constructing the life table and the feeding preference experiment. The results showed that S. litura could complete its development and reproduction normally on asparagus stems or leaves. Although the adult longevity and fecundity of S. litura on the two types of tissues were not significantly different, the development duration of larvae and pupae, and total preoviposition period on leaves were significantly longer than those raised on stems. The intrinsic rate of increase and finite rate of increase were 0.186 d(−1) and 1.204 d(−1) on stems, which were significantly higher than those fed on leaves (0.161 d(−1) and 1.175 d(−1)). The mean generation time on stems (32.88 d) was significantly lower than on leaves (36.88 d). It indicated that stems were more suitable for its population growth. In the feeding preference, the third and fifth instar larvae preferred to feed on leaves, and other instar larvae (except for the sixth instar of 2.5 h) had no significant difference. These results will provide a theoretical reference for further research and forecasting and integrated control.