Susceptibility of five pearl millet (Pennisetum glaucum L. Ecotypes to the nymphal instars of the Migratory locust Locusta migratoria migratorioides (Reiche and Farmaire) infestation.

ABSTRACT

The laboratory experiments were conducted at the unit of biological

control, Insectary laboratory of the Department of Crop Protection,

Faculty of Agriculture University of Khartoum, Shambat, during the

period from the beginning of May 2014 to the beginning of January

2015. The experiments were carried out under semi-field conditions

(cage- experiment). The objectives of the study were to study

investigation and evaluation the susceptibility of five ecotypes of

(Pearl millet Pennisetum glaucum var.) on the life system of the

solitary African Migratory Locust. The main objective was to detect

the most preferred food variety on the development of nymphal instar

(3rd & 4th in stars) of the African Migratory Locust Locusta migratoria

migratorioides (Lin.). Five different experiments with five ecotype

varieties of Pearl millet Pennisetum glaucum var were setup. Each

experiment with three replications were applied topically on the 3rd

and 4th nymphal instars. Each treatment replicated 3 times. Each

experiment took duration of four days. Millet plants were gown in

ground basin and plastic cup to feed the locusts and for experiment

application techniques. Data were recorded daily after 24 hours from

beginning of experiments and were followed until the fourth day. The

food preference and ecotype susceptibility evaluation was based on

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 the significant difference of susceptibility of five

varieties ecotype of pearl millet. The susceptibility of feeding by 3rd

and 4th nymphal instars was clearly observed in all ecotypes.

According to the study results showed the preference of ecotypes by

nymphs was increased according to increasing of application time.

The high one was Bayouda-late maturing compared to four other

ecotypes of treatments. Then Kano-late maturing, Wad elahow-late

maturing, Bayouda-early maturing and Dembi-early maturing

respectively. During the experiments were noticed that the preference

of five ecotypes were high in the first reading and third reading of

experiments.

However the results revealed that the susceptibility of five ecotypes of

pearl millet Pennisetum glaucum var, according to remain amount of

feces in any ecotype variety. The least amount of reminder feces was

in Bayouda-late maturing ecotype, this means that the biggest part of

the food-intaken was ingested, digested and assimilated according to

the four others ecotypes.

The bigger percentages of ingested amount of food consumption for

five ecotypes of pear millet Pennisetum glaucum var, with 3rd and 4th

instars of African migratory locust ranked as above mentioned.

The research concludes that further works on evaluation of

susceptibility of pearl millet varieties with different pest, particularly

in migratory locust is recommended, thus the crucial role in order to

detect the target palatable variety as a trap in pest management

control.