The efficacy of four seed powders on some biological aspects and mortality of khapra beetle

Abstract EN

The seed powders of four plants ; harmal Harmal peganum L., black pepper Piper nigrum L.

radish Raphanus sativus L.

and celery Apinum grave lens L.

were tested at the concentrations 2 %, 4 % and 6 % to evaluate their effects on some biological aspects and mortality of Trogoderma granarium Everts.

The results indicated that the seed powders had toxic effects.

They had significant effect on adult mortality.

There were significant differences between treatments, concentrations and periods of exposure at 5 %.

The highest mortality was 96.6, recorded in celery treatment at concentration of 6 % and 6 days of exposure, followed by pepper 83.3 % , radish 76.6 %, and harmal 73.3 %.

Seed powders had also moderate repellent action against adult insects.

There were significant differences between treatments and concentrations at 5 %.

The highest repellent percentage was 40 %, occurred in celery treatment at concentration of 6 % and period of exposure of 24 hours, followed by pepper 34.6 %, radish 33.3 % and harmal 30 %.

No repellency and mortality noticed in control.

Seed powders had also significant effect on decreasing average number of F1 progeny.

There were significant differences between treatments, concentrations at 5 %.

The number of F1 progeny found in celery treatment at concentration of 6 % was zero, followed by pepper 23, radish 31 and harmal 56.

Whereas in the control was 78.

The seed powders disrupted the life cycle of the insect resulting in prolonging the period of F1 adult appearance ; the periods were 20 days for control, 26 days for harmal and radish, no adult appearance in pepper and celery even after 34 days.

The result showed that the seed powders had significant effect on mortality, repellency and reduction of progeny.

Thus more studies on these plant species are needed to establish their potential sources which might used for stored product protection.