MOHAMAD M. A. KHEDR*, HEND M. SABRY AND REHAB M. EL-GENDY
Plant Protection Research Institute, Agricultural Research Center, Giza, Egypt
*(e-mail : m1khedr@yahoo.com; mobile : +2 01145493942)
(Received : January 14, 2022; Accepted : March, 21, 2022)
ABSTRACT
One integrated pest management strategy to control Spodoptera littoralis (Lipedoptera : Noctudiae) includes
the application of naturally originating insecticides. For the first time the mode of action of a fraction
isolated from the aerial parts of Zygophyllum album plant as an ethanolic extract against S. littoralis has
been reported. The fraction was separated using column chromatography and recognized with gas
chromatography–Mass spectrometry (GC-MS). Scanning and transmission electron microscopes were
used for further analysis, the structural and biochemical changes that occurred in S. littoralis larvae due
to the fraction application were assessed as biomarkers. GC-MS technique showed that pinocarvone
(13.67%) and E-15-heptadecenal (11.47%) were the principal compounds of the Z. album fraction. Also,
such fraction had ovicidal and larvicidal activities against S. littoralis. Compared with control larvae,
abnormalities in the head capsule, antennae, spiracles and integument were observed in the treated
larvae. Moreover, the treated larvae showed significant inhibition of some biochemical activities e. g.
amino acid transferases (AST and ALT), chitinase enzymes, and total soluble protein content. Additionally,
the tested fraction affected some biological parameters such as the incubation period of eggs, larval
mortality, duration of larvae and pupae and weight of pupae. The Z. album fraction proved to be a promising
naturally derived agent for the control of S. littoralis larvae and eggs.
Key words : Zygophyllum album, Spodoptera littoralis, larvicide, ovicide, ultrastructure