Exposure to extremely low frequency electromagnetic fields alters the behaviour, physiology and stress protein levels of desert locusts

Abstract

Electromagnetic fields (EMFs) are present throughout the modern world and are derived from many man-made sources including overhead transmission lines. The risks of extremely-low frequency (ELF) electromagnetic fields are particularly poorly understood especially at high field strengths as they are rarely encountered at ground level. Flying insects, however, can approach close to high field strength transmission lines prompting the question as to how these high levels of exposure affect behaviour and physiology. Here we utilise the accessible nervous system of the locust to ask how exposure to high levels of ELF EMF impact at multiple levels. We show that exposure to ELF EMFs above 4 mT leads to reduced walking. Moreover, intracellular recordings from an identified motor neuron, the fast extensor tibiae motor neuron, show increased spike latency and a broadening of its spike in exposed animals. In addition, hind leg kick force, produced by stimulating the extensor tibiae muscle, was reduced following exposure, while stress-protein levels (Hsp70) increased. Together these results suggest that ELF EMF exposure has the capacity to cause dramatic effects from behaviour to physiology and protein expression, and this study lays the foundation to explore the ecological significance of these effects in other flying insects.

Extremely Low Frequency Electromagnetic Fields impair the Cognitive and Motor Abilities of Honey Bees

“…At ground level ELF EMFs generated under 400 kV transmission lines can reach magnetic flux densities of 100 µT 10 but flying insects could be exposed to even higher levels closer to the conductor, for example 0.6 mT at 1 m, and 14 mT at 1 cm 16 . Recent studies on the desert locust highlight the potential impact of ELF EMFs on insects, where high levels lead to physiological and behavioural changes as well as increased levels of stress proteins 17 .…”

“…Thus, the area around power lines where pollinators may be affected by acute EMF exposure may, therefore, be high. Given what we already know of the effects of EMFs on insects 17 the opportunity is within our grasp to determine the impact of acute ELF EMFs on important pollinators. Here we focus on the commercially important honey bee and ask how ELF EMFs, at strengths found in the environment, affect their motor, cognitive and feeding abilities.…”

Electromagnetic field exposure (50 Hz) impairs response to noxious heat in American cockroach

“…There are also reports showing that EMF affects heat shock protein (HSP) accumulation in cells (Tokalov and Gutzeit 2004 ; Alfieri et al 2006 ; Bernardini et al 2007 ; Li et al 2013 ; Wyszkowska et al 2016 ). Thus, the increase in latency to escape from heat in the examined cockroaches may be a result of heat shock proteins accumulation, which act as molecular chaperones and help denaturated proteins to refold.…”

“…The effects of EMF exposure on insect morphology, physiology and behavior have been proved previously. The EMF exposure induced changes in: mosquito egg hatching (Pan and Liu 2004 ), ovipositon in Drosophila (Gonet et al 2009 ), locomotor activity of desert locust and American cockroach (Wyszkowska et al 2006 , 2016 ) or antioxidant defense in Baculum extradentatum (Todorović et al 2012 ). EMF exposure has been also shown to induce a release of octopamine—an insect ‘stress hormone’ in American cockroach (Wyszkowska et al 2006 ), whereas the static electric field exposure elevated octopamine levels in Drosophila brain (Newland et al 2015 ).…”

Effect of Electromagnetic Field (EMF) and Electric Field (EF) on Some Behavior of Honeybees (Apis melliferaL.)

“…Studies have shown that ELF and EMF cause some physiological and behavioral changes on insects and increase stress protein levels. (Wyszkowska et al2006; Wyszkowska et al 2016). In another study carried out by Rooder (1999), they found that there was a significant increase in the motor activity of insects as EMF increased octopamine levels in insects.…”