BIO-EFFECTS OF CINNAMON (Cinnamomum zeylanicum) BARK EXTRACTS AGAINST Rhizopertha dominica (F.) (COLEOPTERA: BOSTRICHIDAE)

Ceylon cinnamon bark extracts were evaluated under constant
conditions against Rhizopertha dominica adults and the effective lethal
concentrations (LC50 and LC95) of each extract were calculated. Effects of LC50
and LC95 on both reduction of progeny (%) and weight loss (%) were inve
stigated. Also the persistent effect of LC95 of the tested extracts was done weekly
on both adult mortality (%) and grain viability (%). Results showed that percent
adult mortality increased with increase of the concentration and exposure time.
Chloroform extract was the most effective than other extracts, since its lethal
effective concentration (LC50) reached a minimum value of 1.8 mllKg, while the
acetone extract was the least effective which its LCoO was 3.57 mllKg. All tested
extracts significantly reduced adult progeny (%) and weight loss (%) compared to
control. Tested extracts persisted effective on adult mortality (%) for two months
and droppsd suddenly thereafter for all extracts. Tested extracts slightly affected
germination (%) of wheat treated with LC95 value either initially or at end of the
storage compared to control. Cinnamon extracts could be used as wheat
protectant for wheat from R. dominica attack.