Population Fluctuations of the Major Lepidopteran Insect Pests of Date Palm at Al-Wahat Al-Baharia Region, Egypt.

<b>Background and Objective:</b> Several insect pests infest the date palm and its fruit in the field and storage causing economic damage and affecting the tree productivity from one year to another and from one location to another due to the pest's status in the field. Therefore, this study aimed to estimate the seasonal fluctuation of the important insect pests, <i>Arenipses sabella</i>, <i>Batrachedra amydraula</i> and <i>Ephestia</i> sp. during the 3 successive years in the date palm fields at Al-Wahat Al-Bahareia region in Egypt. <b>Materials and Methods:</b> Three light traps were used to capture insects for 3 years, 2018, 2019 and 2020. The survey was done every 2 weeks for the three above-mentioned insects. Each year was divided into five periods according to the production of date palms. Also, the correlation coefficient was estimated between the population fluctuations and meteorological data. <b>Results:</b> In all three seasons, the number of all these insects increased gradually from the beginning of January till the fruiting period (end of July). Then, the numbers decreased gradually starting from August till the end of the year. The correlation coefficient for all estimated pests was more than R = 0.7 except for <i>Ephestia</i> sp. with the humidity (R = 0.6049). <b>Conclusion:</b> All studied lepidopteran insects are presented during the whole year and fluctuated with the highest peak at the fruiting period. Moreover, the increase in temperature and decrease in humidity is correlated with the high numbers of these insects. This study could help control these pests with different methods according to their estimated populations of them.

Field Evaluation of Native Fungus, Beauveria bassiana (Bals.) Vuillemin Against some Piercing-Sucking Insects on the Grapevine.

BACKGROUND AND OBJECTIVE: The Taify cultivar of grapevine (Vitis vinifera L.) is the second important economical fruit after pomegranate at high altitudes of the Taif region in Saudi Arabia. The grapevine trees are infested with different piercing-sucking insect pests especially aphids, whiteflies and thrips. The purpose of this study was to evaluate the ability of an indigenous endophytic entomopathogenic fungus, Beauveria bassiana to control the important piercing-sucking insect pests on grapevines. MATERIALS AND METHODS: This investigation was carried out through 5, 10 and 15 day intervals between sprays for controlling Aphis illinoisensis, Bemisia tabaci and Frankliniella occidentalis with a concentration of 6×106 conidia mL-1 under field conditions. RESULTS: The higher infestation in the untreated control was by aphids followed by whitefly and thrips. At the end of the experiment in the treated trees, aphid and whitefly reduction percentages with 5 day intervals of sprays (98.5 and 96.12%, respectively) were not significantly different from 10 day intervals (95.17 and 91.81%, respectively) while these reductions were significantly higher than the reduction occurred by 15 day intervals of sprays (65.93 and 44.51%, respectively). Meanwhile, the 3 intervals of sprays did not differ significantly in the thrips reduction occurred by them with a range from 93.62-96.46%. CONCLUSION: This indigenous B. bassiana as 6×106 conidia mL-1 with 10 day intervals of the spray-on grapevine can suppress the piercing-sucking insect pests. This also will participate in grapevine organic production and furthermore, it could replace the chemical treatment.