Electrostatic measurement of dischargeable electricity and bioelectric potentials produced by muscular movements in flies (original) (raw)
Related papers
Insects are electrified in an electric field by deprivation of their negative charge
Annals of Applied Biology, 2012
An electric field screen (EF-screen) is a physical device for excluding pest insects from greenhouses and warehouses to protect crops during their production and storage periods. In this study, a simple version of the EF-screen, an insulated conductor iron wire (ICW) paralleled to an earthed net, was constructed to effectively observe the attraction of test insects in relation to their electricity release. The ICW was negatively charged to dielectrically polarise the insulator sleeve of the ICW: negatively on the outer surface and positively on the inner conductor wire surface of the sleeve. The negative surface charge of the ICW caused an electrostatic induction in the earthed net and a resultant positive charge at the ICW-side surface of the net. An electric field formed between the ICW (negative pole) and earthed net (positive pole). Insects were attracted to the ICW when they were placed onto the earthed net. A vital step for the attraction was the creation of a transient bioelectric discharge from an insect. During this discharge, an electric charge of the insect was transferred to the earthed net. Eventually, the insect became net positive and was then attracted to the ICW. The magnitude of the current increased in direct proportion to the increase in voltage applied to the ICW, and the attraction force was directly proportional to the increase in the electric current. Larger voltages were necessary to attract much larger insects because larger insects were stronger and therefore more able to escape from the ICW attraction. Similar results were obtained for a wide range of pest insects belonging to different taxonomic groups (8 orders and 15 families). This study demonstrated that transient bioelectric discharge is common in insects and can be utilised to create an electrostatic force capable of moving insects in a generated electric field.
Analysis of Pole-Ascending–Descending Action by Insects Subjected to High Voltage Electric Fields
Insects
The present study was conducted to establish an electrostatic-based experimental system to enable new investigations of insect behavior. The instrument consists of an insulated conducting copper ring (ICR) linked to a direct current voltage generator to supply a negative charge to an ICR and a grounded aluminum pole (AP) passed vertically through the center of the horizontal ICR. An electric field was formed between the ICR and the AP. Rice weevil (Sitophilus oryzae) was selected as a model insect due to its habit of climbing erect poles. The electric field produced a force that could be imposed on the insect. In fact, the negative electricity (free electrons) was forced out of the insect to polarize its body positively. Eventually, the insect was attracted to the oppositely charged ICR. The force became weaker on the lower regions of the pole; the insects sensed the weaker force with their antennae, quickly stopped climbing, and retraced their steps. These behaviors led to a pole-a...
Static electric fields modify the locomotory behaviour of cockroaches
Journal of Experimental Biology, 2011
Static electric fields are found throughout the environment and there is growing interest in how electric fields influence insect behaviour. Here we have analysed the locomotory behaviour of cockroaches (Periplaneta americana) in response to static electric fields at levels equal to and above those found in the natural environment. Walking behaviour (including velocity, distance moved, turn angle and time spent walking) were analysed as cockroaches approached an electric field boundary in an open arena, and also when continuously exposed to an electric field. On approaching an electric field boundary, the greater the electric field strength the more likely a cockroach would be to turn away from, or be repulsed by, the electric field. Cockroaches completely exposed to electric fields showed significant changes in locomotion by covering less distance, walking slowly and turning more often. This study highlights the importance of electric fields on the normal locomotory behaviour of insects.
Journal of Computational Neuroscience, 1996
The passive membrane properties of the tangential cells in the fly lobula plate (CH, HS, and VS cells, ) were determined by combining compartmental modeling and current injection experiments. As a prerequisite, we built a digital base of the cells by 3D-reconstructingindividual tangential cells from cobalt-stained material including both CH cells (VCH and DCH cells), all three HS cells (HSN, HSE, and HSS cells) and most members of the VS cell family . In a first series of experiments, hyperpolarizing and depolarizing currents were injected to determine steady-state I-V curves ). At potentials more negative than resting, a linear relationship holds, whereas at potentials more positive than resting, an outward rectification is observed. Therefore, in all subsequent experiments, when a sinusoidal current of variable frequency was injected, a negative DC current was superimposed to keep the neurons in a hyperpolarized state. The resulting amplitude and phase spectra revealed an average steady-state input resistance of 4 to 5 Ma and a cut-off frequency between 40 and 80 Hz . To determine the passive membrane parameters R, (specific membrane resistance), Ri (specific internal resistivity), and C, (specific membrane capacitance), the experiments were repeated in computer simulations on compartmental models of the cells . Good fits between experimental and simulation data were obtained for the following values: R, = 2.5 k!&m', Ri = 60 Qcm, and C, = 1.5 pF/cm2 for CH cells; R, = 2.0 kRcm2, Ri = 40 Qcm, and C, = 0.9 pF/cm2 for HS cells; R, = 2.0 kQcm2, Ri = 40 acm, and C, = 0.8 pF/cm2 for VS cells. An error analysis of the fitting procedure revealed an area of confidence in the R,-Ri plane within which the R,-Ri value pairs are still compatible with the experimental data given the statistical fluctuations inherent in the experiments . We also investigated whether there exist characteristic differences between different members of the same cell class and how much the exact placement of the electrode (within *lOO pm along the axon) influences the result of the simulation . The membrane parameters were further examined by injection of a hyperpolarizing current pulse . The resulting compartmental models ) based on the passive membrane parameters determined in this way form the basis of forthcoming studies on dendritic integration and signal propagation in the fly tangential cells (Haag et al.
International Journal of Biometeorology, 1996
An electrohydrodynamic (EHD) system which generated air ions within a strong electric field was used to study responses of stored-product insects Tribolium confusum (du Val) and Plodia interpunctella (Hfibner). Larval mortality of both species generally increased with increased exposure time to ions of either polarity. The larvae and pupae of T. confusum suffered a higher mortality rate than the adults. The insects initially exhibited distinct avoiding motions away from regions of high towards low fluxes of air ions of both polarity. Insects moved vigorously, tumbled, flipped, curled up, and aggregated when the EHD system was turned on. The control insects not exposed to air ions survived and showed a total absence of such behaviour. For bipolar exposures, the insects occupied the neutral zone where the effects were minimal due to cancellation of the fields. Prolonged exposures of more than 20 rain produced a quiescent state. EHD-enhanced mass transfer of the liquid component from physical objects established in fluid mechanics was invoked as a possible cause for insect mortality and avoiding behaviour to ions. Body fluid losses increased linearly with time of exposure (R2>0.97) for all biological stages of insect growth. The larvae and pupae of T. confusum lost 12 and 15% of their body fluids, respectively, after 80 rain of exposure to negative air ions. Fluid losses of such a magnitude are likely to have contributed to insect fatality.
Triboelectrification of houseflies (Musca domestica L.) walking on synthetic dielectric surfaces
Journal of Electrostatics, 2002
Houseflies (Musca domestica L.) have been found to accumulate significant electrostatic charges when walking on uncharged dielectric surfaces. The number of steps taken was found to determine the amount of charge transferred whereas time, on its own, did not play a significant role. After walking only a short distance, typically 30 cm, flies reached saturation charge. The level of this varied according to the position of the surface in the triboelectric series relative to the fly. The rate of charging (pC/footstep) was directly proportional to the difference between the fly's charge and its saturation charge, hence the initial rate of charging for an uncharged fly was directly proportional to the saturation charge. A model has been fitted to the relationship between distance travelled (and hence the number of steps taken) with charge. The reciprocal charge left on the surface has been visualised using photocopier toner. r
Static electric field detection and behavioural avoidance in cockroaches
Journal of Experimental Biology, 2008
Electric fields are pervasively present in the environment and occur both as a result of man-made activities and through natural occurrence. We have analysed the behaviour of cockroaches to static electric fields and determined the physiological mechanisms that underlie their behavioural responses. The behaviour of animals in response to electric fields was tested using a Y-choice chamber with an electric field generated in one arm of the chamber. Locomotory behaviour and avoidance were affected by the magnitude of the electric fields with up to 85% of individuals avoiding the charged arm when the static electric field at the entrance to the arm was above 8-10 kV m -1 . Electric fields were found to cause a deflection of the antennae but when the antennae were surgically ablated, the ability of cockroaches to avoid electric fields was abolished. Fixation of various joints of the antennae indicated that hair plate sensory receptors at the base of the scape were primarily responsible for the detection of electric fields, and when antennal movements about the head-scape joint were prevented cockroaches failed to avoid electric fields. To overcome the technical problem of not being able to carry out electrophysiological analysis in the presence of electric fields, we developed a procedure using magnetic fields combined with the application of iron particles to the antennae to deflect the antennae and analyse the role of thoracic interneurones in signalling this deflection. The avoidance of electric fields in the context of high voltage power lines is discussed.
Proceedings. Biological sciences / The Royal Society, 2015
Natural and anthropogenic static electric fields are commonly found in the environment and can have both beneficial and harmful effects on many animals. Here, we asked how the fruitfly responds to these fields and what the consequences of exposure are on the levels of biogenic amines in the brain. When given a choice in a Y-tube bioassay Drosophila avoided electric fields, and the greater the field strength the more likely Drosophila were to avoid it. By comparing wild-type flies, flies with wings surgically removed and vestigial winged flies we found that the presence of intact wings was necessary to produce avoidance behaviour. We also show that Coulomb forces produced by electric fields physically lift excised wings, with the smaller wings of males being raised by lower field strengths than larger female wings. An analysis of neurochemical changes in the brains showed that a suite of changes in biogenic amine levels occurs following chronic exposure. Taken together we conclude th...
Mechanical and electrical activity in the indirect flight muscles of the honey bee
Zeitschrift f�r Vergleichende Physiologie, 1968
1. Recordings were made from single elements in the indirect flight muscles of the honey bee with the usual insulated metal electrodes uninsulated at the tip. With the "indifferent" electrode in the head few neighboring elements showed up. All recorded elements had random phase differences. 2. In the dorsoventral (DV) muscles about 80% of the spikes are not followed by striking junctional components, 20% are. Practically all spikes from the dorsolongitudinal (DL) muscles have a junctional component following. 3. The DV-muscles in the intact animal shorten linearily with increasing action potential frequency (Fig. 6). The DL-musclcs are stretched slightly. 4. Approximately 50 to 100 msec before the onset of oscillations the action potential frequency in both groups of muscles (DV and DL) increases to 30-60 Ilz for 2 to 4 action potentials. The DV-muscles shorten (evidently isotonieally) about 20 to 40 tz and start oscillations with a lengthening. An experiment performed by BOETTIGER (p. 438) might explain the events that start the oscillations. The oscillations end about 180 to 200 msec after the ending of the action potentials. The DV-muscles return to their resting length in the next 200 to 1,000 msec. 5. The duration of the action potentials depends strongly on the temperature (Fig. 4). 6. The wingbeat frequency increases with the action potential frequency (Fig. 1O). Zusammen/assung. 1. Bei Ableitung yon Einzelelementen aus den indirekten * Supported by tile National Science Foundation, grant GB 6528.