Evaluation of five pearl millet ecotypes susceptibility to the nymphal instars of migratory locust

Abstract

Abstract. Gomaa KFS, Bashir MO. 2017. Evaluation of five pearl millet ecotypes susceptibility to the nymphal instars of migratory locust. Trop Drylands 1: 57-63. African migratory locust (Locusta migratoria migratorioides) is among the most devastating pests in African dry land, threatening the sustainability of agricultural crops including the pearl millet (Pennisetum glaucum). This study aimed to investigate the susceptibility of five ecotypes of pearl millet to the nymphal instars of the solitary African migratory locust and to detect the most preferred millet variety. The experiments were undertaken under semi-field (cage-experiment) conditions. Five different experiments with five ecotype varieties of pearl millet Pennisetum glaucum var. were setup. Each experiment with three replications was applied topically on the 3^rd and 4^th nymphal instars. The food preference and ecotype susceptibility evaluation were based on the amount of food intake in grams, weight of food ingested and digested in gram, percentages, and amount of weight of feces in gram. The results showed a significant difference in susceptibility of five ecotypes of pearl millet. The susceptibility of feeding by 3^rd and 4^th nymphal instars was observed in all ecotypes. The study results showed that the preference of ecotypes by nymphs was increased according to increasing application time. The highest one was Bayouda-late maturing compared to four other ecotypes. During the experiments, we noticed that the preferences of five ecotypes were elevated in the first and third readings of experiments. However, we discovered in the study that the susceptibility of five pearl millet ecotypes was according to the remaining amount of feces in any ecotype variety. The least amount of reminder feces was in Bayouda-late maturing ecotype, which means that most of the food intake was ingested, digested and assimilated as with the four other ecotypes. The greater percentages of ingested amount of food consumption for five ecotypes of pearl millet, with 3^rd and 4^th instars of African migratory locust, ranked as mentioned above. The research concludes that further works on evaluation of susceptibility of pearl millet varieties with different pests, particularly in migratory locust is recommended to detect the palatable target variety as a trap in pest management control.