Potency of Alhagi maurorum plant extracts as phytoacaricidal against Panonychus citri (Acari: Tetranychidae)

Abstract

Recently, botanical insecticides have more alertness in pest control programs for its various advantages. Alhagi maurorum plant (camel thorn) one of the important medicinal plants in Fabaceae. The phytoacaricidal activity of A. maurorum plant extracts was evaluated against Panonychus citri. The aerial part of A. maurorum was extracted by methanol, petroleum ether, and water separately using the soaking and Soxhlet extraction. The rate of female daily deposited eggs varied considerably according to A. maurorum plant extracts and the sublethal concentrations. A few numbers of eggs laid were observed with the methanol extract (0.73 eggs), petroleum ether (2.16 eggs), and aqueous (4.31 eggs) at LC 75 , while the high number observed in the untreated female groups (29.37 eggs) and Selecron insecticide (6.99 eggs). The same pattern was occurred in the hatchability with the tested bio-acaricides compared with Selecron insecticide and untreated ones. Based on sublethal dose LC 25 , LC 50, and LC 75 , the tested acaricides was significantly reduced the number of hatched eggs, where it reached (30.7, 13, 5.6%), (37.6, 21.6, 15%) and (44.3, 30.8, 23.8%) for methanol, petroleum ether, and aqueous plant extract, respectively compared with untreated groups (91.2%). Concurrently, data showed that methanol extract has a significantly impacted on the reduction of viability (58.16%) and reproductive process while the effect was less with the aqueous plant extracts (46.21%). Gas chromatography/mass spectrometry (GC-MS) analysis identified various bioactive complexes (phenols, tannins, and fatty acids) with insecticidal activity. The peak of compounds was higher in Benzene, (1-butylhebtyl)-undecane, 5-phenyl (8.75 %), Maltol 4H-pyran-4-one,3-hydroxy-2-methyl(2.74%) 9,12,15-Octadecatrienoic acid, linolenic acid (2.45%) in petroleum ether extract and 4H-pyran-4one,2,3-dihydro-3,5-dihydroxy-6-methyl (3.66%), 2-Furancarboxaldehyde, 5-(hydroxymethyl) (3.33%), Bis(2-ethylhexyl) phthalatehalic acid, bis(2-ethylhexyl)ester (5.58%) in methanol extract. 2,3-Dimethylpenzene-1,4-dicarbonitrile (20.26%), 4-Fluoroveratrole, fluorobenzene,3,4-methoxy (19.52%) and Hexadecanoic acid (0.87 %). Finally, we concluded that methanol, petroleum ether, and aqueous extracts screened showed phytoacaricidal activity against mite P. citri.

Palm Red Mite Management with Soursop Seed Plant Residue Extracts

“…As an example of phenolic compounds, tannins play important roles in pest organisms, such as anti-food and food deterrent properties, as they reduce the efficiency of digestion in phytophagous arthropods through their chemical bonds [22]. Mostafa et al [23] studying the allelopathic effect of Alhagi maurorum extract as a phytocaricide against the mite Panonychus citri (Acari: Tetranychidae), found an increase in the mortality rate of individuals due to the presence of tannin compounds. Flavonoid compounds, although observed in smaller amounts in this study, act on insects and mites by altering enzymatic and hormonal activity, blocking biochemical pathways, and consequently reducing the assimilation of essential substances and nutrient storage [20].…”