Dose-response relationship between abamectin and mortality of Panonychus ulmi (Acari: Tetranychidae)

60-65In this study, the dose-response relationship between abamectin and mortality of larval and adult forms of Panonychus ulmi (Koch) was established. Abamectin was investigated at a dilution series of 1/1, 1/1.15, 1/1.35, 1/1.6, 1/2, 1/2.55, 1/4, 1/8 and 1/16 of its field recommended concentration, in order to calculate the ECi – values. Results showed that the lowest ECi – values were observed on larvae, which showed high sensitivity to abamectin than adults. Both statistical models led to satisfactory findings and the linear model was ranked as the best model for describing the dose-response relationship. This research highlighted the importance of toxicity risk assessments to obtain a more accurate estimation of the compatibility of abamectin in the integrated pest management (IPM) programs

L’effet de quatre variétés de pommier sur la biologie et la démographie de l’acarien rouge: Table de vie à deux sexes de Panonychus ulmi (Acari: Tetranychidae)

The effect of four apple varieties on the development and reproduction of the European red spider mite Panonychus ulmi (Koch, 1836) (Prostigmata: Tetranychidae) was studied under the controlled conditions of 25 ± 1 °C, Relative Humidity of 65 ± 5 % and photoperiod of 16:8 (L:D). The age-stage two-sex life tables of P. ulmi on Golden Delicious, Red Shief, Jeromine and Gala varieties were constructed. Based on higher values of fecundities (38.5 and 35.1 eggs / female) and the intrinsic rates of increase (rm) of 0.1643 and 0.1521 day-1, Panonychus ulmi developed better on Golden Delicious and Red Shief among the varieties tested. Results show that the developmental time of female adults was shorter on Golden delicious and (11.2 days). Immature survival of P. ulmi was significantly higher on Golden delicious, Jeromine and Red Shief (79.1, 76.5 and 72.3 %,respectively), and lower on the Gala variety (64.5 %). In the light of these results, Panonychus ulmi develop and reproduce quickly on Golden Delicious and Red Shief varieties among the four varieties tested. Establishment of two-sex life tables of P. ulmi on apple varieties facilitates the rational management of this phytophagous mite according to the principles of integrated management. Keywords: Panonychus ulmi, life table, apple, fecundity, Development, ReproductionL’effet de quatre variétés de pommier sur le développement et la reproduction de Tétranyque rouge de pommier Panonychus ulmi (Koch, 1836) (Prostigmata: Tetranychidae) a été étudié sous conditions contrôlées de 25 ± 1 °C, humidité relative de 65 ± 5% et photopériode de 16:8 (L:D). Les tables de vie à deux sexes de P. ulmi sur Golden delicious, Red Shief, Jeromine et la variété Gala ont été construites. En se basant sur les valeurs élevées de fécondités (38,5 et 35,1 œufs/femelle) et les taux intrinsèques de croissance (rm) de 0,1643 et 0,1521 jour-1, Panonychus ulmi s’est mieux développé sur Golden delicious et Red Shief que les autres variétés testées. Les résultats montrent aussi que le temps de développement total des femelles immatures était plus court sur Golden delicious (11,2 jours). La survie des immatures a été significativement élevée sur Golden Delicious, Jeromine et Red Shief (79,1; 76,5 et 72,3 %, respectivement) et faible sur la variété Gala (64,5 %). A la lumière de ces résultats, Panonychus ulmi se développe et se reproduit rapidement sur les variétés de Golden Delicious et Red Shief parmi les quatre variétés testées. L’établissement des tables de vie à deux sexes de P. ulmi sur les variétés de pommier facilite la gestion raisonnée de cet acarien phytophage conformément aux principes de la gestion intégrée. Mots clés: Panonychus ulmi, table de vie, pommier, fécondité, développement, reproductio

Dose-response relationship between abamectin and mortality of Panonychus ulmi (Acari: Tetranychidae)

In this study, the dose-response relationship between abamectin and mortality of larval and adult forms of Panonychus ulmi (Koch) was established. Abamectin was investigated at a dilution series of 1/1, 1/1.15, 1/1.35, 1/1.6, 1/2, 1/2.55, 1/4, 1/8 and 1/16 of its field recommended concentration, in order to calculate the ECi – values. Results showed that the lowest ECi – values were observed on larvae, which showed high sensitivity to abamectin than adults. Both statistical models led to satisfactory findings and the linear model was ranked as the best model for describing the dose-response relationship. This research highlighted the importance of toxicity risk assessments to obtain a more accurate estimation of the compatibility of abamectin in the integrated pest management (IPM) program

The psychological properties of the Arabic BDI-II and the psychological state of the general Moroccan population during the mandatory quarantine due to the COVID-19 pandemic

The main objective of this work is to study the psychological impact (stress and depression) of the mandatory quarantine applied on the Moroccan population in order to limit the spread of the new coronavirus (COVID-19), then the study of the psychometric properties of the Arab BDI-II in the general Moroccan population. 263 respondents were asked to respond to a BDI-II and PSS-10 socio-demographic questionnaire conducted during the first month of quarantine. 55.9% of the respondents were in a normal state of stress and 36.1% in a moderate state. However, 38.4% and 27.8% exhibited minimal and severe depression respectively. The results of factor analysis with the varimax rotation method revealed three factors predicting 55.56% of the total variance of BDI-II, while two factors predicting 60.97% of the total variance of PSS-10. Cronbach's alpha values for BDI and PSS-10 were α = 0.93 and α = 0.58 respectively. In conclusion, the BDI-II is a reliable and valid assessment for measuring symptoms of depression in the general Moroccan population and also very important to pay more attention to the side effects of mandatory quarantine

Repercussion du stress repete par la chaleur et de l'administration de faibles doses de corticosterone pendant la deuxieme semaine post-natale sur la formation des cellules dans le cervelet du jeune Rat

SIGLET 55270 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc