Abstract:
This work was carried out at Alfashir locality, North Darfur State, Sudan,
during season 2017/2018 under laboratory condition and field surveying to find out
alternative method for pesticide to protect cowpea seeds from infestation by the
beetle Callosobruchus maculatus (Coleoptera: Bruchidae) by using some botanical
plants.
This study included a field survey to determine the presence, distribution and
infestation of legumes seeds, cowpea, faba bean and kidney bean by the adults of
cowpea beetle in three areas, crops market, Almoushi market and Nafasha
market(locality Alfashir).
The study showed that the pest was present and distributed along the State
specially in Alfashir areas, with high infestation rate (80%) in August on Faba bean
at Almousha market and followed by (78%) in July on cowpea at Almousha market.
Laboratory studies were done in the lab. of Biological Science, Faculty of
Eduction , Alfashir University to evaluate the efficacy of the five botanical leaves (
powder, aqueous and ethanolic extracts) of Ocimum basilicum, Azadirachta indica,
Solenostemma argel, Datura stramonium and Nicotiana rustica against adult of
cowpea beetle, various concentrations of powder and aqueous extrac (5%, 10% and
15%) and ethanolic extract (2%, 3% and 5%) were tested as potential source of
control agent for adults of cowpea beetle. all treatments were arrange in Completely
Randomized Design (CRD) and the data was subjected to Analysis of Variance
(ANOVA) using SAS and SPSS computer software package (version21) at 0.05
Significant levels. Means were separated using Least Significant Difference (LSD).
The obtained data revealed promising activities of the five botanical plants
leaves powder and aqueous, ethanolic extracts at different concentrations, powder
aqueous(5%, 10% and15%) and ethanolic (2%, 3% and 5%) against the tested adult
compared to the control for 24, 48 and 72 hours.the best result was obtained using
ethanolic extracts of Nicotiana rustica in all concentrations caused high mortality to
the tested adults.
Generally the result indicates that the lethal effect of ethanolic extracts of N.
rustica was higher than that of Hargel followed by ocimum, neem and then datura
leaves extract on adults of cowpea beetle.
The LD50 of powder leaves of hargal, neem, ocimum, datura and tabocco were,
0.669,7.371, 96.94, 2.545 and3.180 respectively. Aqueous extracts were 3.679, 5.708,
2.72, 4.95 and 18.40, respectively. Ethanolic extracts were 2.482, 2.55, 3.107, 0.87
respectively.
The preliminary phytochemical analysis of ( hargal, ocimum, neem, datura and
tabocco) indicates the presence of different biochemical compounds. The major
bioactive compounds according to their high peak areas were, Ocimum basilcum
(pentamethyl pentaphenicylcyclopenlasiloxane, peak area 3.63%), Azadirachta
indica (5,10,15,20-teraphenyl[2-(2)HI](prophyrinalo)zinc(11), peak area 3.99%),
Solenostemma argel (2-[2,6-Bis(hex-5-enyloxy)phenyl]-9-[2-(but-3-enyloxy)-6-hex-
5-enyloxy)phenyl]-1,10-phenanthroline, peak area 3.66%), Datura stramonium (2-
hydroxy-5,10,15,20-tetraphenylporphinato)copper(11), peak area 3.84%) and
Nicotiana rustica (pyrrolidine N-(4-methyl-3-pentenyl, peak area 99.25%).