The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), and the carmine spider mite, Tetranychus cinnabarinus (Boisduval), are two of the most important mite pests of different host plants in Egypt. These mites are spreading rapidly because of their resistance to acaricides; therefore, it was necessary to develop a new biological control tactics for mite management. Plant extracts, such as garlic extract (Allium sativum Linn.), may represent easy, available and viable alternative, because they are considered to be minimum-risk pesticides. A series of laboratory and semi-field experiments were considered to determine the susceptibility of adult mite females to different concentrations of garlic aqueous extract (G.A.E.). Mortality was measured upon treatment with five concentrations ranging from 1 to 25% W/V. Female mortality increased with concentration, T. urticae was more tolerant than T. cinnabarinus through laboratory studies as maximum mortality values were 90% and 100% after 24 hours using concentration 25% W/V, respectively. The chemical composition of the Allium sativum aqueous extract was characterized by GC/MS analysis which revealed the occurrence of 33 compounds, of which the major compound was identified as 2-Furancarboxaldehyde,5-(hydroxymethyl). The efficacy of G.A.E. was evaluated against T. urticae and T. cinnabarinus under semi-field conditions. Highest reduction (89.75 %) in T. urticae population was recorded by using concentration 50% W/V one day after treatment (DAT). T. cinnabarinus was more tolerant under the semi-field conditions as the reduction was (80.14 %) using the same concentration. G.A.E. is effective in the control of both tetranychids. It is promising candidates for biological control of these two mite pests.

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Field experiments were carried on soybean variety (Giza 111) during two successive seasons 2019 and 2020. Two natural compounds were tested, Humic acid, Chitosan Nano-particles (C.N.Ps) and a common acaricide, Abamectin, of recommended dose rates and one treatment left without spraying as control by using Economy Micron ULVA sprayer (15L./fed.) and Hydraulic sprayer (Matabi) (56 L/Fed.). Data indicated that all tested compounds induced significant negative influenced on Tetranychus urticae adult females' survival. Abamectin and humic acid revealed successful results followed by the C.N.Ps. Results showed that C.N.Ps have lower toxicity on T. urticae but it safer on all movable stages of Amblyseius californicus, Orius insidiosus, and Scolothrips sexmaculatus, the natural enemies associated. It could be recommended that using those compounds with LV spraying equipment with not less than (15 L. /Fed.). A satisfactory spray coverage was obtained on soybean plants. The droplets spectrum ranging from 150-170 m (VMD). A sufficient number ranging from 18-199 N/cm². The data showed that the Economy Micron ULVA sprayer was the best equipment to control. Tetranychus urticae on soybean according to the homogeneity of the droplet spectrum. The rate of performance of Hand-held Hydraulic sprayer (Matabi) (56 L. /Fed.), Economy Micron ULVA (15 L. /Fed.) were 3.55 Fed. /day, 3.30 Fed. /day, respectively. Data also revealed that lost spray-on ground for Ulva sprayer was lower than Matabi sprayer with 35%.

The efficacy of Fenugreek, Trigonellafoenum graecum, Celery, Apium graveolens Laurel, Laurus nobilis and Thyme, Thymus vulgaris extracts, against the four stored grains pests, rice weevil, Sitophilus oryzae, cowpea beetle, Callosobruchus maculatus, mould mite, Tyrophagus putrescentiae and house dust mite, Dermatophagoides farinae were investigated. Mortality (%) increased with increasing concentrations, exposure periods and varying from plant to plant. Petroleum ether extract of A. graveolens induced 100% mortality after two, eight and seven days of exposure for C. maculates, S. oryzae and D. farinae, respectively. Foenum graecum caused 100% mortality after four, five and seven days for S.oryzae, D. farinae and T. putrescentiae, respectively and 93.3% for C. maculates after five days. Petroleum ether extract of L. nobilis caused 100% mortality to C. maculatus, T. putrescentiae and D. farina but declined to48% with S. oryzae. T. vulgaris caused a complete reduction in F1-progeny for C. maculatus but had no effect against S. oryzae moderate effect on T. putrescentiae and D. farinae. A. graveolens and T. foenumgraecum were the most toxic plants followed by L. nobilis; while T. vulgariswas the least. For all plants, petroleum ether extracts were more effective in mortality percentage and reduction in F1-progeny than acetone extracts.