The biological and biochemical effects chloropyrifos, camphor extract and
their combination were studied against the 4th instars of Spodoptera littoralis under
semi-field conditions. The results indicated that the LC50 for chloropyrifos was 0.08
ppm and 13.3 x 103 ppm for the camphor extract. The estimated Co-toxicity factor
was 13.2 So, there is an additive effect between camphor oil and chloropyrifos against
S. littoralis.
Oil extract of camphor prolonged larval and pupal duration also the same effect
happened when using mixture of camphor extract and chloropyrifos. This
prolongation was accompanied with a reduction in pupal weight of the treated larvae.
While when using chloropyrifos only the larval and pupal duration were shortened
Also % of pupation and % of adult emergence were more decrease in plant extract
and insecticide mixture than each compound alone.
Biochemical studies showed that, total protein content of larval instars
decreased by 31, 26 and 13.5 % for camphor extract, chloropyrifos and its
combination, respectively. Also, the activity of acid phosphatase, α-esterase was
significantly decreased. Where the alkaline phosphatase, activity increased When
compared with control.