Interaction of Static Magnetic Fields (SMF) with Biology of Tetranychus urticae Koch (Acari)

Abstract

A laboratory experiment was conducted to study the effects of Bio-assay of the economic mit9' Tetranychus urticae Koch by the levels oi static magnetic field forces. Completely randomized experiment with three replicates was designed' Similar groups of egg s of T. Lrticae were exposed to the odd numbers of magnets ; 1,3 and 5 units ( 0.14-4.0 ml.t. ) and even numbers of magnets; 2,4 arld6 (2.6-4.24 ml.t. ) . Check was left without magnetizing. The observations included, egg hatchability percentage, incubation period, life cycle, longevity, life span, survivability, mean number of eggs / female urd r"* ratio of the 1 ,t generation. Results showed that there was a linear negative relationship between the force of magnetic field and the percentage of egg hatchability. Hatching eggs were decreased from 100 Yo h the check to 90'3% in 6 magnet unit's treatment. Also mean number of eggs and longevity decreased from 4.0 eggs &16.9 days to 2.3 eggs & ll.4 days; while incubation period and life cycle were prolonged depending on the number of magnet pieces from 7'0 & 15.7 days to 8.4 & 12.0 days, respectively of the above-mentioned magnets exposure.