Effect of Magnetic Field on Metabolism and Enzyme Activity in Some Harmful Insects

Abstract

To investigate the effect of magnetic field on the physiological aspects of some insects, larvae of three insects were reared in laboratory under 22 ±2°C and 60 ±5% RH in a suitable rearing boxes. The three insects were: cotton leaf warm, Spodoptera littoralis, red palm weevil, Rhynchophorus ferrugineus and the greater wax moth, Galleria mellonella. Rearing insects started with a suitable larval instar. Numbers of larvae (form each insect) divided into 2 similar and equal groups, the first reared as a control (without magnetic field), while the second group was exposed to the magnetic field, (MF) along rearing periods. An appropriate numbers of larvae from the control and the treated ones were taken for Bio-chemical analysis and the main parameters were recorded. The measured physiological parameters were: total protein, total carbohydrates, total lipids, invertase enzyme and alkaline phosphatase. Magnetic flux in around the center of the rearing plastic containers for the three insects were prepared and adjusted with similar magnates. Strength of the magnetic flux was measured using millitesta apparatus. It was recorded an average of 0.218, 2.487 and 8.629 ml.t. for the 3 insects respectively.Results showed that each of body weight and growth rate as well as the physiological aspects were affected with the magnetic field. Rate of growth was negatively affected as it decreased in cotton leaf worm and red palm weevil. Results also demonstrated that invertase enzyme decreased in the treated larvae of S. littoralis ans G. mellonella with 40.15% and 28.33% respectively lower than the control. In the same time, magnetic field led to increase the invertase enzyme in R. ferrugineus with 71.6% higher than the control samples. In spite of the strong magnetic flux around the larvae of G. mellonella their influence was limited. This may be due to the special behaviour of the worms as they of internal presence and entrance inside the rearing media for these larvae.