No abstract

The experiments were conducted in the laboratory Plant Protection Research Institute Dokki-Giza, to study the effect of Anethum groveolenus Dill, Ambrosia maritime Damaseia extract, Cumminum cyminum Cumin; Syzyguim aromaticum Clove and Allium maritime Garlic on activity of some enzymes in(Tuta absoluta Meyrick) on tomato plants were investigated. After the tested compounds application, the results revealed that these compounds had various effects on the activity alkaline phosphatases, α and β esterases and carbohydrates hydrolyzing enzymes (trehalase, invertase and amylase). The enzyme activity reduced or increased significantly. Activity of alkaline phosphatases, α and β esterases were higher in Damasiea on T. absoluta, in comparison to control. The percentage of increase of alkaline enzymes activity were +22.28 and +17.38 and +13.34 % in T. absoluta respectively. Also, in cumin and garlic extracts treatments. Generally, in case of T. absoluta treatments, the results of damasiea extract indicated high increase (+40.1% in comparison to control) in activity of beta-esterases and invertase enzymes but high decrease (+45.9%), in alpha-esterases activity only. The results indicated that the damasiea extract had direct effects on the metabolism in the body Tuta absoluta.

No abstract

Impact of abiotic (minimum-maximum temperatures and relative humidity) and biotic factors (Coccinella undecimpunctata, Syrphus corollae , Amblyseius swirskii, Nesidiocoris tenuis and Chrysoperla carnea) on the population dynamics of Bemisia tabaci (Genn.) and Tetranchys urticae (Koch) infesting tomato plant Lycopersicon esculentum L. at kafr El sheikh governorate, Egypt were studied on spring plantation of 2016 &2017 seasons. The analysis of variance revealed significant variation among dates of observations, lines and in their interaction for B. tabaci (Genn.), T. urticae (Koch) and their natural enemies. The mean number of B. tabaci and T. urticae during the first season was higher than that was recorded during the second season. The percentage of explained variance (E.V.) of abiotic and biotic altogether in the population densities of B. tabaci and T. urticae in the first season was stronger percentage values than second as (62%-86%) and (94%-77%) for eggs and nymphs of B. tabaci while (84% _ 77%) and (84%-98%) and for eggs and movable stages of T. urticae during spring of plantation 2016 &2017 seasons, respectively.

In the present study, insecticidal Activity of essential oils (lemon grass Cymbopogon citratus, thyme Thymus vulgaris and geranium Pelargonium graveolens) and silver nanoparticles (AgNPs) synthesized by using tested essential oils were evaluated against female of P. solenopsis Tinsley. At high concentration (40µl/l), the percentages of p. solenopsis mortality recorded 100, 100 & 86.70%, for thyme, lemon grass and geranium EOs, while it recorded 100, 90 and 83.3 % at (400ppm) of AgNPs-thyme, AgNPs-lemon grass, and AgNPs-geranium after 72hrs of treatment. All essential oils and AgNPs were proved to be very toxic to female of p. solenopsis. However, thyme essential oil and AgNPs-thyme recorded the highest mortality percentage with LC 50 = 8.094 μl/l & 86.645 ppm, respectively, followed by lemon grass (bulk & AgNPs-lemon grass oil) and geranium oil (bulk & with AgNPsgeranium oil).