Evaluation of some plant extracts against adults of the Saw-toothed grain beetle, Oryzaephilus surinamensis

Abstract

A survey was appliedin grain stores in Omdurman Locality (Hi Alarab- Libya market – Omdurman Estate - Dura market-Date market).The survey recorded infestation in dry Dates by two important pests, the Saw -toothed grain beetle (Oryzaephilussurinamensis ), and Date Moth (Ephestiacautella ) and other economic pestsof different crops.Concerning pest control methods at the stores, the survey indicated that, 70 % of the stores use chemical methods for the protection. Laboratory studies were carried out to determine the effects of three plant extracts on the adult of the saw toothed grain beetle Oryzaephilussurinamensis . The three plants were (Usher (Calotropisprocera, Argel ( Solenostemmaargel ), Datura (Datura stramonium) , used at three conditions (Powder , water extract , ethanol extract) . The Results revealed that , at the three doses applied (5%, 10% and 15% ), all plants tested have shown some potential insecticidal effect.Usher , C . procera (Ethanol extract ) was the most effective, and causedhigh lethal effect on the adults, with a percentage mortality of (30%) after 48 hrs. Also, the ethanol extract of Argel recorded similar results as Usher, with a percentage mortality of (26 – 30%) of adults at all concentrations. In the experiment of (Treated sack penetration), the D.stramoniumwater extract was the best, compared with Usher and Argel extracts, as it showed high effect at concentration (15%), with an average penetration effect of (1,3) in the second week, compared with a penetration effect of (10) with the control. Concerning the chaise of (WPI), for evaluationof botanical extracts as grain protectants (as : Strong, Weak, or Negative) , an evaluation was made for the extracts of the 3 plants, at 3 concentrations (10, 20, and 3o (W/W), to study their effects on the larvae of Khapra beetle. The results showed that, of the 3 plants screened, D.stramonium showed the best grain protectant effect,(Chick pea )with a WPI value of (24) at dose of 30% (w/w) , while the less grain protectant effect was recorded by Argel at dose 10% (w/w) with a WPI value of 40.63.