This study aimed to evaluate the
efficiency of hydrophilic silica nano-particles at 500 ppm concentration compared
with recommended chemical insecticide “Malathion" against Callosobruchus
maculatus Fab. (Coleoptera: Chrysomelidae) under laboratory stored
conditions. C. maculatus is a major pest of cowpeas in Egypt.
Hydrophilic silica-nano-particles showed that the number of C. maculatus,
mortality  were 99 ± 1.2, 96 ± 3.2, 100 ±
0.0 and 100 ± 0.0 % six, four, two months 
and  zero time post treatment;
respectively, reduced to 5 ± 4.2, 12 ± 6.2 , 24 ± 3.2 and 63 ± 1.2 in case of
using Malathion. Biological parameters revealed decrease of egg number and seed
damage % with hydrophilic silica nano-particles. This investigation recommends
Silica nano-particles as an effective matter in control C. maculatus
under laboratory condition with low damage in cowpea seeds. Also, we need more
study on the effect of using different degrees of temperature during using
silica nanoparticles on pest suppression.