Physiological and biochemical effects of Olea europaea leaf extracts from four phenological growth stages on the oogenesis of female locust Locusta migratoria

Abstract

The effects of olive leaf extract (OLE) are studied on several reproductive variables and the ovarian biochemical composition of Locusta migratoria (Orthoptera: Acrididae) adult females. The methanolic extracts are prepared from the leaves sampled during four phenological growth stages of olive tree: cluster formation (Cf), swelling inflorescence buds (Sib), full flowering (Ff) and endocarp hardening (Eh). When applied to adult females during the pre-ovipositional phase, the treatment elicites a significant adverse effect on their reproductive potential. Indeed, OLE significantly reduces both fecundity and fertility and affects oocyte growth during the first gonadotrophic cycle, as indicated by measurements of ovarian weight, length of terminal oocytes and ovarian index. Furthermore, OLE is examined with respect to ovarian biochemical components. Biochemical analyses reveal a significant reduction of ovarian contents of proteins, lipids and carbohydrates, suggesting a disruption in the incorporation of the haemolymph metabolites in the oocytes and an interference of OLE with the vitellogenesis process. The antigonadotrophic effect is confirmed by a histological study of the ovaries, which clearly shows a delay in ovarian development and in yolk accumulation in the basal oocytes of treated females. The most effect is noted with the extract prepared from the leaves collected at the swelling inflorescence buds for all measured parameters, which appears to be related to its high content of polyphenols. Acrididae) comprise the two major species. These species exhibit phenotypic plasticity, known as density-dependent phase polyphenism, where individuals can exist anywhere between two extreme forms (solitarious versus gregarious) that differ in their morphology, physiology, behaviour, ecology and propensity to cause agricultural damage (Lazar et al., 2016;Cullen et al., 2017). Locusts at the solitarious form cause little damage to agricultural crops but, in the gregarious phase, they are responsible for substantial damage to crops and grazing, as

Effects of Pergularia tomentosa active fraction on the oogenesis of the desert locust, Schistocerca gregaria: ovarian biochemical composition, and effects on the ecdysteroid pathway

“…Adult fecundity and fertility (egg hatchability or viability) are very important reproductive parameters for investigating the effects of some plant compounds (Shaalan et al ., 2005; Acheuk et al ., 2012). Likewise, their interaction with reproduction and its hormonal regulation represent potential targets for the development of botanical insecticides (Abdellaoui et al ., 2018). The analysis of the result for several variables measured here, revealed that the treatment of S. gregaria females during the previtellogenic period with AFPt, significantly reduced both fecundity and fertility and increased the duration between emergence and first oviposition.…”

“…Similarly, Abdellaoui et al . (2018) reported that treatment of adult females during the pre‐ovipositional phase with olive leaf extract elicited a significant adverse effect on the reproductive potential of L. migratoria by significantly reducing both fecundity and fertility.…”

Status and Prospects of Botanical Biopesticides in Europe and Mediterranean Countries

“…For example, a decrease in oviposition of Damalinia limbata was detected in neem-exposed female lice. Abdellaoui et al [ 123 ] reported that the application of olive leaf extract (OLE) resulted in decreased fecundity and fertility and limited oocyte growth during the first gonadotropic cycle. Furthermore, OLE reduced the protein, lipid and carbohydrate content of ovaries, indicating a disruption in the embodiment of the haemolymph substrates in the oocytes and interference with the vitellogenic process.…”

The Effect of Abamectin on Locusta Migratoria Neurosecretory Cells and Mid Gut, Using Ultrastructure Examination, Oxidative Stress Study, and In-Silico Molecular Docking

“…The emergence of insecticide-resistant strains and a desire to reduce the use of synthetic chemicals in the environment has led to alternative control methods being investigated. Interest has grown in using plant extracts that have a low toxicity to mammals and other locust predators, as well as a high rate of bio-degradation in the environment [11][12][13].…”

“…Alkaloids, terpenoids, phenols, flavonoids, steroids, and other allelochemicals produced by the secondary metabolism of plants may provide a safer source of pesticides as a substitution for persistent synthetic insecticides [14,15]. More than 200 plant species have been identified as having insecticidal characteristics, but only a small fraction of these have undergone adequate evaluation [11]. For example, experiments were carried out to determine the impact of a crude methanolic extract from the endemic Tunisian plant Pergularia tomentosa on the development and physiology of L. migratoria nymphs.…”