The date, palm, Phoenix dactylifera is the most significant agricultural product in the Middle East region, in which Saudi Arabia is ranked as the top producing country. One of the most critical problems facing date production is insect infestation. Ephestia cautella is one of the most harmful insects to date, causing significant damage. Different techniques have been used against E. cautella through the use of synthetic chemical pesticides, but they have a negative impact on the environment. Recently, research has been directed towards seeking alternatives to these methods.In the current study, a biological system using Salvadora persica shoot extract for the control of E.cautellahas been evaluated. To this end, mortality rates LD50 and LD90 were determined when the different concentrations of the plant extract were applied at different developmental stages (larvae, pupa, and adult male/female) over a period of three days. Furthermore, some chemical constituents of the plant extract were determined by preliminary chemical tests and by using Gas chromatography–mass spectrometry (GC-MS). Results from current investigation have displayed that the mortality rate was dependent on both the developmental stage and concentrations of the plant extract. Total phenolics and the saponin content of the plant extract were detected. GC-MS analysis identified the potential chemical agents in the plant extract that may possess the insecticidal ability. In light of the current findings, it is clear that infestation of date palms by E.cautella can be controlled by using S. persica shoot extract. To optimize the implementation of this technique, we recommend that future research focus on testing other organic solvents and other plant parts so that the most biologically active biomolecules responsible for the control of E. cautella under date storage conditions can be accurately determined.

Entomopathogenic fungi (EPF) are considered effective methods for investigating insects’ immunity in response to infection. Insects have a variety of defense mechanisms against infectious diseases, namely phenoloxidase, hemocytes, detoxification and antioxidant enzymes.The instinctive immune system of insects is highly advanced and depends on humoral and cellular elements. In this study, five haemocytes types were found in fifth nymphal instar and adults of green bug, Nezara viridula (Heteroptera: Pentatomidae) namely; prohaemocyte (pr),granulocyte (gr), spherulocyte (sp), plasmatocyte (pl), coagulate cells (co) and oenocytoid (oe). Infection with Beauveria bassiana significantly decreased the different haemocytes count in both fifth nymphal instar and adults, especially after 72h post-infection. The haemocytes’ response against fungi was also investigated. A significant increase in Alpha esterase (EST), Acid phosphatise (ACP) and Alkaline phosphatise (ALP) were observed after 72h post infection in the haemolymph of N. viridula adults. In contrast, phenoloxidase activity significantly decreased in adults’ hemolymph after the same period of infection. Results indicated that infection with B. bassania affects the number of circulating haemocytes and decreases phenoloxidase activity. 

Aflatoxins have great significance due to health hazards to men and other useful animals. The aflatoxins are produced by Aspergillus flavus and A. parasiticus. Recently, the use of natural products like cinnamon and clove oil has also been suggested for the inhibition of aflatoxin production as well as growth of A. parasiticus. In view of the known antifungal properties of plant extracts, an attempt has been made in the present investigation to explore the Antifungal Activity of Plant extracts against growth of A. flavus by some wild plants of family Asteraceae, viz., Ageratum conyzoides, Carthamus oxycantha, Eclipta alba, Echinops echinatus, Launea nudicaulis, Lactuca dissecta, Parthenium hysterophorus, Sonchus aspera, Vernonia cinerea and Xanthium strumarium have been studied against growth of toxigenic strain of A. flavus by standard cup method on solid medium. The diameter of zone of inhibition was measured in mm and percent inhibition in growth was calculated. Out of three concentrations viz., 10, 15 and 20 per cent of leaf extracts, the 20 per cent concentration was found most effective. Further, hot water extract of leaf was adjudged more inhibitory as compared to cold water extract of plants. The maximum inhibition (70%) in growth of test fungus was caused by hot water leaf extract of A. conyzoides. It also can be concluded that leaf extract of different experimental plants have antifungal activity to varying extents.

Ethanol extracts of Alpinia galanga (L.)Willd. (rhizome), Coscinium fenestratum (Goetgh.) Colebr. (stem), Piper betle Linn. (leave), Piper longum L. (fruit), Zingiber cassumunar Roxb.(rhizome) and chitosan were evaluated for their fungicidal activities in controlling Alternaria leaf spot of Chinese kale, caused by Alternaria brassicicola, under field conditions. The results showed that the application of these plant extracts resulted in reduction of disease severity in a concentration-dependent manner. Among the five plant extracts tested, the extracts of P. betle and C. fenestratum at a concentration of 10,000 ppm displayed potent fungicidal activity in the suppression of disease severity, causing 43% and 41% disease reduction, respectively. The extracts of Z. cassumunar and A. galanga at 10,000 ppm showed moderate effectiveness in controlling the disease, causing 28% and 25% disease reduction, respectively, whereas the extract of P. longum at the same concentration possessed the lowest antifungal activity, reducing the disease severity by less than 20% at the highest dosed tested. The application of chitosan at 2% had a moderate effect; it reduced the disease severity by 30%. However, the application of the systemic fungicide, iprodione, displayed the greatest fungicidal activity in suppression disease severity, causing 65% disease reduction. The results in this study indicated that the P. betle and C. fenestratum may be promising eco-friendly candidates for controlling Alternaria leaf spot disease in Chinese kale production.