Ecological and Toxicological Studies on Date Palm Scale Fiorinia phoenicis Balachowsky (Hemiptera-Diaspididae) Infesting Three Date Palm Cultivars with Reference to Anatomical and Chemical Analysis of Palm Cultivars Leaflets

Abstract: Abstract: One of the most significant fruits in the Middle East is the date palm. Dates are vulnerable to
infestation by a variety of pests, including, Fiorinia date scale, Fiorinia phoenicis Balachowsky (Hemiptera-
Diaspididae), which infests the palm fronds and sucks the sap and the infestation extends to the date fruits in
the case of severe infestation and leads to making the fruits unacceptable for consumption. This experiment
aimed to study the population density of date palm scale F. phoenicis on three different date palm cultivars,
they represent the three main groups of date palm cultivars in Egypt to determine the proper time to be
controlled and evaluation of some pesticides and their alternatives. Furthermore, the levels of several chemical
substances (including total phenols, proline, total indoles, amino acids, total protein, peroxidase, polyphenol
oxidase, chlorophyll a and chlorophyll b) in the leaves of both infested and healthy tested date palm cultivars
were quantified. The difference in the anatomical structure of the leaflet was also studied in the three tested
palm cultivars. The results showed that the population density of the F. phoenicis recorded three peaks of the
three insect stages for each year of the two studied years 2021/2022 and 2022/2023. The three peaks resulted
in three overlapping generations during each year of the two studied years as follows: early summer, late
summer and fall generations. The results also showed that there was no significant difference between the
insect population in the two years of the study, while there were significant differences between the insects
population on the tested date palm cultivars, where the Siwi cultivar recorded the highest number, followed
by the Bartamoda cultivar and then the lowest number of insects was the Samani cultivar. Obtained pest
dynamics over the three date palm cultivars showed as three intervals of activity per year regardless palm
cultivar. Effect of maximum, minimum temperature and % RH was evaluated over each interval (as partial
regression) as well as plant ages (as third degree of polynomial) were determined. Both models were significant
with superiority to plant age model. The results of the control experiment on the most affected date palm
cultivar, Siwi showed that average reduction rate for the three checks after 2 , 4 and 6 weeks, in case of the
mixture of (New oil 95% EC + Kimithrene 25% SC) showed the highest efficiency in reducing the insects
population with an average of 88.58%, followed by Palmito gold 25% EC with an average of 81.43%, then
Admiral with an average of 80.89%, while the effect of the moderate reduction of the insect population of the
pesticides Kemithrene 25% SC, New oil 95% EC and Prev-AM 6% (W/V) with averages of 76.74, 75.02 and
73.78% respectively, it had the least effect on reducing the number of Fresh oil 95% EC with an average of
65.23%. F. phoenicis' responses to the tested treatments at various life stages revealed that the nymphal stage
was the most vulnerable, followed by adults and gravid females. Obtained data indicated that the infested date
palm tree leaves contained high significant quantity of proline, total phenols, peroxidase and polyphenol
oxidase in leaves, whereas total indoles, amino acids, total protein, chlorophyll a and chlorophyll b contents
Publication year 2023
Organization Name
Author(s) from ARC
Publication Type Journal