Bio-efficiency of some Aromatic Oils and Other Compounds on Some Biological Aspects of Tetranychus urticae as Alternative to Pesticides.

Abstract

Extensive use of conventional pesticides and acaricides to control of the two spotted spider mite, Tetranychus urticae Koch caused undesirable side effects on environment, humans and animals so, it was necessary to look for alternative control methods including the use of aromatic oils and natural oils, as botanical acaricides . The present study was carried out to assessment bio-efficiency of some aromatic oils and other compounds on some biological aspects of T. urticae in laboratory at (25±2) ºC, and (65±5) %R.H. to finding safe a mean to human, environment , and animals as alternative to synthetic miticides used in the control this mite. Results indicated that Helbstar was the highest toxic compound to adult females of T. urticae followed byNat-1 with Lc50 values of 1686.5 and 2861.5 ppm, respectively while Basil was the least toxic one with Lc50 value of 5990.4 ppm . The population showed more homogeneity in its response to the aromatic oils (Basil and carnation). As a result to significant differences between different oils it was found that Carnation oil and natural oil (Nat-1) can be recommend in controlling mite through incubation stage of T. urticae . Also Carnation oil can be recommend in controlling active proto-nymph, total immature and life cycle stages of T. urticea . All oils were not preferred in controlling adult females of mite through pre-oviposition, oviposition, post-oviposition and longevity stages . The obtained results were important so they are taken in the consideration when planning programs of integrated pest management.

Lethal and Sublethal Effects of Mixed Pesticides on Tetranychus urticae Koch and its Predator Phytoseiulus persimilis

“…These outcomes are in agreement with those of Elsadany et al (2021) that hypothesized that one of the main signs in the development of a resistant strain is the reduction in the slope of the dosage mortality line, in this way one can expect that compounds with low slope value might prompt to improve resistance if utilized successively. Assessing the toxicity of a pesticide to phytoseiids by estimating female mortality alone underestimates the true effect of residual exposure (Irigaray et al, 2007).…”

“…In addition, results showed that Romectin gold displayed higher slope (0.683) over AgriFlix (0.439). Elsadany et al (2021) reported that the slope value is considered as an indicator of the reaction between the chemical and the tested organism. As the highest slope value means greater homogeneity of the organism response towards the pesticide, whereas the low slope value demonstrates heterogeneous response of the organism to the tested chemical.…”