Determining the electromagnetic field parameters to kill flies at livestock facilities

Abstract

We have considered the electromagnetic method to kill the larvae of flies ‒ agricultural pests. To address the task, a problem on the distribution of electromagnetic fields in their body was solved. The solution is based on the Maxwell's equations in the integral form, which automatically take into consideration the boundary conditions at the surface of the larvae. Since we propose the electromagnetic radiation whose wavelength is much larger than the linear sizes of insects, the derived integral equations were solved in the approximation of quasi-statics. That made it possible to convert them into a system of inhomogeneous linear algebraic equations whose solution is the components of electric field inside the larvae of flies. The study was conducted for the single-layer and two-layer insects of an ellipsoidal shape. The obtained fields provide a possibility to determine the magnitudes of potentials that occur at the larva cover, as well as to find out which of these values lead to breaking this cover with the ensuing death of the fly larva.To construct a dependence that would relate the number of imago from the larvae of flies to the parameters of electromagnetic radiation in the presence of an additive disturbance of a random character, we employed a full-factorial second-order planning. Electromagnetic radiation was applied to the fly larvae at the end of the second age. The exposure of fly larvae to the electromagnetic radiation was carried out in a frequency range of 10.2–9.8 GHz, a power flux density of 0.62‒038 mW/cm2 and an exposure of 2‒12 s. The development of larvae was observed until the formation and release of an adult insect.Based on a multifactor experiment, we derived the optimal values for the frequencies of radiation, power flux density, and exposure. To suppress insects at livestock facilities, starting from the larval stage and up until the release of imago, the electromagnetic radiation is needed with the following parameters: frequency is 10.2 GHz; power flux density is 0.37 mW/cm2; relative instability of the generator frequency is 10-8, exposure is 6 s. The release of imago from the pupae of fly larvae at livestock premises, irradiated with electromagnetic radiation, was less than 5 %.The experiment with piglets showed that when the chemical method for treating the premises was applied, a gain in the live weight amounted to 7.2 %; when the electromagnetic method was used, it was 9.2 %. A smaller increase in the live weight upon chemical treatment is due to the fact that a chemical solution exerts a negative impact not only on flies and their larvae, but also on animals. The study that we conducted could be used to create industrial installations to kill the larvae of flies at livestock facilities.