The continuous use of pesticides can cause many serious problems in the environmental system.
So, it is very necessary to go back to nature again and look for safe alternatives to chemical pes-
ticides. During this research, we evaluated the toxicity of two types of natural substances (wood
vinegar and seaweed extract) against three types of zoological pests, two-spotted spider mites
(Tetranychus urticae) and two land snails (Monacha cartusiana and Eobania vermiculata). Results
indicated that wood vinegar and seaweed extract had negative effects on eggs, immature stages
and adults of T. urticae. Their mortalities were significantly increased with increasing of the applied
dose of wood vinegar and seaweed extract. The highest mortalities of eggs, immature stages and
adults of T. urticae were 82.9, 71.8 and 98.4% and were 75.3, 62.9 and 83.9% after 72 h from the
application of wood vinegar and seaweed extract, respectively. Data showed also a positive relation-
ship between the mortality percentages of snails and the concentration. The highest mortality rates
for M. cartusiana and E. vermiculata (73.91 and 60.87%) and (91.67 and 83.33%) were recorded
due to the use of wood vinegar and seaweed extract at the concentration of 25% individually. The
values of LC50 and LC90 were calculated and the results confirmed that the seaweed extract was
more toxic for the tested land snails than wood vinegar. The higher values of LC50 of wood vinegar
and seaweed extract (21.67% and 11.87%) were selected for the biosafety tests in mammals by
using Rattus norvegicus albinus males. It was clear that both wood vinegar and seaweed extract
had no harmful effects on mammals according to the non- significant differences in liver and kidney
functions (ALP, AST, ALT, Creatinine and urea in the blood samples) between treated and untreated
rats. |
