A comparison of methods for trapping rice weevils in stored wheat

Rice weevils (Sitophilus oryzae) in bulk-stored wheat grain were trapped over a 14-week period to enable weevil numbers to be estimated. Three different trapping methods were used: a grain spear, cone traps and grain probes. The cone traps gave the best indication of the populations of adult weevils present in the grain, although significant relationships between catch number and actual populations were established for all traps. When juveniles were present in the grain none of the traps gave an accurate prediction of actual weevil numbers present. The numbers caught in individual traps at similar population levels varied, which indicates that several traps should be set in each grain lot to give satisfactory estimations of weevil populations. The use of cone traps in commercial practice requires further investigation.