English

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. The present study was carried out biological control unit of Insectary Laboratory, Department of Crop Protection, Faculty of Agriculture, University of Khartoum, Shambat, Sudan. The study lasted from during the beginning of May 2014 to January 2015. The experiments were undertaken under semi-field (cage-experiment) conditions. The primary objective of the study was to detect the most preferred food variety on the development of nymphal instars (3rd & 4th instars) of the locust. 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 3rd and 4th nymphal instars. Each experiment lasted for four days. We grew the Millet in ground basin and plastic cup to feed the locusts and for experiment application techniques. Observed variables were recorded daily after 24 hours from the start of experiments until the fourth day. The food preference and ecotype susceptibility evaluation were based on the amount of food intake in gram, weight of food ingested and digested in gram, percentages, and amount of weight of feces in gram. The results showed a significant difference of susceptibility of five ecotypes of pearl millet. The susceptibility of feeding by 3rd and 4th nymphal instars was observed in all ecotypes. The study results showed that the preference of ecotypes by nymphs was increased according to increasing of 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 3rd and 4th 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 pest, particularly in migratory locust is recommended to detect the palatable target variety as a trap in pest management control.