Abstract: The global agricultural sector suffers from the damage due to insect pests on plants all over the world, forcing farmers to indiscriminately use mineral fertilisers and chemical pesticides that are toxic and affecting the environment, plants and animals, as well as causing serious health problems to farmers and consumers. Therefore, scientists and researchers were forced to investigate and discover new methods until they explored the field of nanoscience, which shows great potential for applications in diverse fields, including agriculture, chemicals and plant protection by controlling harmful insect pests. Therefore, a biological method was used to synthesise the laboratory-prepared copper nanoparticles that were tested on both eggs and larvae phases in mosquitoes as nanocides using acidic Citrus Nargin broth (10%). A total of 1 mM aqueous CuSO4 of the plant extract was reduced and synthesised into stable copper nanoparticles with an average size of less than 450 nm. Then, the composition, size and percentage of the synthesised nanoparticles were determined using ultraviolet spectroscopy, X-ray diffraction, FTIR, SEM and AFM techniques. The results of this study showed high mortality and a significant difference (P ≤ 0.01) for mosquito eggs and larvae when exposed to the nanocide, than those found in the extract of bitter leaves and the regular copper sulfate insecticide used in agriculture against insects. The results also showed a high relative efficiency of 100% with a highly significant difference (P ≤ 0.01) after exposure of insects and their different stages to the nanocide after 72 hours. We conclude from this study the possibility of synthesising nanoparticles using mineral compounds with natural, safe and environmentally friendly bio-plant extracts as insecticides for various agricultural pests.
