tailieunhanh - Comparative feeding and digestive performance of four lepidopteran species of larvae on onion, allium cepa var aggregatum L. as a host plant

Shallot, Allium cepa var aggregatum L. (Alliaceae) is one of the major bulbous vegetable grown both as garden and field crop in India. The major leaf feeding insect pests of onion, Spodoptera exigua, Spodoptera litura, Helicoverpa armigera and the recently invasive insect Spodoptera frugiperda were causing destructive damage to the plant and made economic yield loss. Food consumption indices were studied under laboratory condition at room temperature 28 ± 20C and it is one of the parameter to identify the damage potential of insects. The growth rate (GR) and Efficiency of Conversion of ingested food (ECI) was significantly different in third instar but fourth and fifth instar, they showed less significant difference or on par with each other. The high GR and Consumption Index (CI) was observed in S. exigua ( mg/day and mg/day respectively), Efficiency of Conversion of Digested food (ECD) () and ECI () was the highest in S. litura in third instar but in fourth instar the highest ECD () and ECI () was observed in S. frugiperda and no significant difference was noticed in fifth instar for ECI and ECD. The grand mean GR and CI was the highest in S. exigua ( mg/day), ( mg/day) and the AD, ECD and ECI was the highest in H. armigera (), S. frugiperda (), S. litura () respectively. The lowest Consumption Rate (CR) and CI were observed in S. litura ( mg/day and mg/day), and ECD and ECI were noticed in H. armigera ( and (). The results of food consumption indices had indicated that S. exigua followed by H. armigera caused more damage on shallot onion than the other two caterpillars studied but effective utilization of food was made by S. litura and S. frugiperda. | Comparative feeding and digestive performance of four lepidopteran species of larvae on onion, allium cepa var aggregatum L. as a host plant