Dynamics of three phytophagous mites Tetranychus urticae, Panonychus citri and Eutetranychus orientalis (Acari, Tetranychidae) on citrus in Tunisia

Phytophagous mites of the family Tetranychidae are important pests of citrus in Tunisia, reducing the quality of the product in marketing value every year. In this study, the population dynamics of Tetranychus urticae, Panonychus citri and Eutetranychus orientalis were studied in the nursery and in the field from the beginning of February until the end of May. The results showed that the population dynamics of these three mites varied with temperature. The evolution of the T. urticae population showed three peaks in February, mid-March and April. In addition, the population of E. orientalis showed four peaks in February, March, April and May. For P. citri, this mite is active in winter and spring when climatic conditions are favourable for its development. Field monitoring has shown that the fauna of predatory mites linked to these three plant pests is diverse. Three species (Neoseiulus californicus, Phytoseiulus persimilis, Euseius stipulatus) of the phytoseiid family have been identified. Given the diversification of predatory mites and their importance in the regulation of phytophagous mites, it is necessary to favor biological control by conserving these species, for which it is important to reason chemical control

Effectiveness of Flonicamid 50 wg against Bemisia tabaci (Genn.) under greenhouse conditions in Tunisia.

Flonicamid is a systemic insecticide that acts as a feed blocker with potential use against whiteflies in an IPM program. The efficacy of flonicamid against populations of Bemisia tabaci in geothermal greenhouses in southern Tunisia. Flonicamid was tested in irrigation and foliar spraying on a greenhouse tomato crop. The use of the insecticide in irrigation or foliar spraying showed significant insecticidal activity on eggs, larvae and adults of B. tabaci. They are comparable to those caused by the reference insecticide confidor and different from those of the control on the different stages of development of B. tabaci. It is advisable to use flonicamid in an integrated pest management program in a heated greenhouse

Efficacy of Emamectin benzoate, Spinosad and Tolfenpyrad on Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) infesting a tomato crop under geothermal greenhouses in Southern Tunisia

The tomato leaf miner, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), is considered one of the most devastating pests of tomato crops in geothermal greenhouses. It leads to crop losses reaching 100% among farmers and major tomato exporters. In this research, three insecticides, Emamectin benzoate, Spinosad and Tolfenpyrad were evaluated for their efficacy in the control of T. absoluta larvae in heated greenhouses. These three treatments resulted in a significant reduction in the number of T. absoluta larvae compared to an untreated control. The Emamectin Benzoate, Spinosad and Tolfenpyrad used were effective in controlling this leafminer with efficacy percentages above 60% against young larvae and above 50% against old larvae

Comparison of the effectiveness of the most used chemicals against Tuta absoluta in Tunisia

Control failures with several chemicals have prompted research into the resistance status of Tuta absoluta and the effectiveness of certain active ingredients against this pest. In this context, a comparison was made of the effectiveness of the most widely used chemicals against T. absoluta in Tunisia. The results show that the L1 larval stage of Tuta absoluta is very sensitive to all of the chemicals tested. Stage L2 is sensitive to Spinosad, indoxacarb and emactin, while Bacillus thuringiensis, martine do not cause 50% mortality. L3 stage mortality fluctuates between 20% and 80% mortality. The L4 stage is more affected by the treatment with Bacillus thuringiensis which can go to 100%. Based on these results, chemical treatments should be directed according to the dominant larval stage in the plants

Glyphosate adsorption onto porous clay heterostructure (PCH): kinetic and thermodynamic studies

The synthesis of PCH from natural bentonite produces a porous heterostructure material effective for the adsorption of glyphosate from water. The adsorption process takes place through an interaction between the silanol group of montmorillonite and/or the PCH adsorbent with the functional groups of glyphosate. The glyphosate adsorption isotherms, recorded for all the studied samples, have been established to be of Langmuir type. The kinetic of the herbicide adsorption on the PCH was best described by the pseudo-second-order model. With the increase in temperature from 25 to 50 °C, the sorption capacities of the materials studied towards glyphosate increased. The process of glyphosate adsorption was found to be endothermic and spontaneous in nature, as indicated by positive values of ΔH and negative values of ΔG. According to the results obtained, the herbicide sorption was more effective in a basic environment. The maximum amount of adsorbed glyphosate is almost doubled with PCH from 13.5 mg/g of natural clay to 27.5 mg/g of PCH.This study was partially funded by project RTI2018-099668-BC22 of Ministerio de Ciencia, Innovación y Universidades, and project UMA18-FEDERJA-126 of Junta de Andalucía and FEDER funds. Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature and Funding for open access charge: Universidad de Málaga / CBUA

Effectiveness of Flonicamid 50 wg against Bemisia tabaci (Genn.) under greenhouse conditions in Tunisia.

Flonicamid is a systemic insecticide that acts as a feed blocker with potential use against whiteflies in an IPM program. The efficacy of flonicamid against populations of Bemisia tabaci in geothermal greenhouses in southern Tunisia. Flonicamid was tested in irrigation and foliar spraying on a greenhouse tomato crop. The use of the insecticide in irrigation or foliar spraying showed significant insecticidal activity on eggs, larvae and adults of B. tabaci. They are comparable to those caused by the reference insecticide confidor and different from those of the control on the different stages of development of B. tabaci. It is advisable to use flonicamid in an integrated pest management program in a heated greenhouse

Dynamics of three phytophagous mites Tetranychus urticae, Panonychus citri and Eutetranychus orientalis (Acari, Tetranychidae) on citrus in Tunisia

Phytophagous mites of the family Tetranychidae are important pests of citrus in Tunisia, reducing the quality of the product in marketing value every year. In this study, the population dynamics of Tetranychus urticae, Panonychus citri and Eutetranychus orientalis were studied in the nursery and in the field from the beginning of February until the end of May. The results showed that the population dynamics of these three mites varied with temperature. The evolution of the T. urticae population showed three peaks in February, mid-March and April. In addition, the population of E. orientalis showed four peaks in February, March, April and May. For P. citri, this mite is active in winter and spring when climatic conditions are favourable for its development. Field monitoring has shown that the fauna of predatory mites linked to these three plant pests is diverse. Three species (Neoseiulus californicus, Phytoseiulus persimilis, Euseius stipulatus) of the phytoseiid family have been identified. Given the diversification of predatory mites and their importance in the regulation of phytophagous mites, it is necessary to favor biological control by conserving these species, for which it is important to reason chemical control

Efficacy of Emamectin benzoate, Spinosad and Tolfenpyrad on Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) infesting a tomato crop under geothermal greenhouses in Southern Tunisia

The tomato leaf miner, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), is considered one of the most devastating pests of tomato crops in geothermal greenhouses. It leads to crop losses reaching 100% among farmers and major tomato exporters. In this research, three insecticides, Emamectin benzoate, Spinosad and Tolfenpyrad were evaluated for their efficacy in the control of T. absoluta larvae in heated greenhouses. These three treatments resulted in a significant reduction in the number of T. absoluta larvae compared to an untreated control. The Emamectin Benzoate, Spinosad and Tolfenpyrad used were effective in controlling this leafminer with efficacy percentages above 60% against young larvae and above 50% against old larvae

Comparison of the effectiveness of the most used chemicals against Tuta absoluta in Tunisia

Control failures with several chemicals have prompted research into the resistance status of Tuta absoluta and the effectiveness of certain active ingredients against this pest. In this context, a comparison was made of the effectiveness of the most widely used chemicals against T. absoluta in Tunisia. The results show that the L1 larval stage of Tuta absoluta is very sensitive to all of the chemicals tested. Stage L2 is sensitive to Spinosad, indoxacarb and emactin, while Bacillus thuringiensis, martine do not cause 50% mortality. L3 stage mortality fluctuates between 20% and 80% mortality. The L4 stage is more affected by the treatment with Bacillus thuringiensis which can go to 100%. Based on these results, chemical treatments should be directed according to the dominant larval stage in the plants