Differential Feeding Preference and Performance of Leafworm Spodoptera litura Fabricius (Lepidoptera: Noctuidae) on some Cultivars of Potato (Solanum tuberosum L.)

Abstract

| Leafworm Spodoptera litura Fabricius is a highly polyphagous pest of food, forage, vegetable and horticultural crops. This sporadic species is becoming an emerging threat to the potato crop in central Punjab and is being evidenced infesting potato crop in Sargodha, Faisalabad and Okara districts. This in-vitro study assessed the comparative feeding preference, food consumption and utilization rates and larval development of S. litura on different white and red skinned potato cultivars. Feeding bioassays revealed that all parameters including leaf weight loss, larval weight gain, relative food consumption and growth rates and conversion efficiency of the ingested food were statistically significant (P ≤ 0.05). Exotic potato cultivars Diamant, Desiree and Asterix exhibited maximum leaf consumption and larval weight gain (i.e. 264.61, 259.37 and 233.01 mg and 121.46, 120.17, 120.13 mg, respectively) concomitantly with maximum values of relative growth rate (RGR), relative consumption rate (RCR) and ingested food conversion efficiency (ECI). Cultivars Lady Rosetta, Cardinal, Ajax, Kuroda and Sante exhibited intermediate values. Minimum feeding preference and susceptibility to S. litura was shown by the native potato cultivars Faisalabad Red and Faisalabad White with minimum food consumption, larval weight gain, RGR, RCR and ECI values, and hence are recommended to indigenous potato growers for commercial cultivation in areas where S. litura threatens potato crop.