Efficiency of lanthanum nitrate La (NO3)3 on the physiological processes of tomato leaf miners Tuta absoluta (Lepidoptera: Gelechiidae) infesting tomato plants

Abstract

A current study was carried out to evaluate the efficiency of the earth element lanthanum (La) in a form Lanthanum nitrate La (NO3)3 on  controlling the serious pest Tomato leaf miners Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) infesting tomato plants through its effectiveness on the physiological processes of T. absoluta. Experiments were carried out at two different zones (Governorates); Dokki  zone (Giza Governorate) and Tokh zone (Qaliobya Governorate) during season 2022 under plastic greenhouses. Experiments were  conducted on tomato plants Lycopersicon esculentum (var. Lopena) (Spring planting). Data obtained showed that tomato seedlings  which were treated with low concentration of lanthanum nitrate La (NO3)3 (1ppm) had lower infestation by the successive insect T.  absoluta compared to control. While tomato seedlings which are treated with a high concentration of lanthanum nitrate La (NO3)3  (5ppm) had higher infestation by the successive insect T. absoluta compared to the control. Laboratory analysis which was conducted on  T. absoluta insects (Larvae) indicated to the effectiveness of La (NO3)3 on the physiological processes of T. absoluta especially the  important enzymes secreting by that insect; (Alpha Esterase, Beta Esterase, Lipase Enzyme, Kinase Enzyme, Chitinase Enzyme,  Phosphatase Enzyme, Oxidation Enzymes and Digestive Enzymes). And indicated also that the low concentration of La (NO3)3 had a  negative effect on these enzymes and on the other hand the high concentration of La (NO3)3 had a positive effect on these enzymes.  Statistical analyses showed that there were highly significant differences between the effectiveness of La (NO3)3 on the physiological        processes of T. absoluta compared to the control.