Common Inhibitory Motoneurones in Insects

1969 ◽  
Vol 50 (2) ◽  
pp. 445-471 ◽  
Author(s):  
K. G. PEARSON ◽  
S. J. BERGMAN
Keyword(s):  
Periplaneta Americana ◽  
Schistocerca Gregaria ◽  
Locusta Migratoria ◽  
Adductor Muscle ◽  
Dual Function ◽  
Muscle Fibres ◽  
Inhibitory Conditioning ◽  
Innervation Patterns ◽  
Antagonistic Muscles ◽  
Leg Position

1. The innervation patterns of the metathoracic posterior coxal levator muscles of the cockroach, Periplaneta americana, have been investigated, and the mechanical effects produced by activity in the axons to these muscles studied. 2. These muscles are innervated by four excitatory and two inhibitory axons. The three smallest excitatory axons may be classified as slow and the largest as fast. Some single muscle fibres are quintuply innervated by all but the fast axon, and some may be innervated by all six. 3. One of the inhibitory axons is a branch of a common inhibitory neurone. This neurone sends branches out all but one of the ipsilateral nerve trunks to innervate synergic and antagonistic muscles. 4. A similar common inhibitory motoneurone has been found in both the locust species, Locusta migratoria and Schistocerca gregaria. In the locust two branches of this common inhibitory neurone correspond to the inhibitory axon innervating the extensor tibiae muscle and the inhibitory-conditioning axon innervating the anterior coxal adductor muscle. 5. Possible functions of common inhibitory neurones in insects are discussed. In the cockroach this neurone may have a dual function: (a) to regulate leg position when the animal is standing, and (b) to facilitate relaxation of the depressor muscles; this allows a more rapid and stronger leg levation when the animal is walking.

The Action of Iontophoretically Applied Glutamate on Insect Muscle Fibres

1968 ◽  
Vol 49 (1) ◽  
pp. 83-93
Author(s):  
R. BERÁNEK ◽  
P. L. MILLER
Keyword(s):  
Equilibrium Point ◽  
Neuromuscular Junctions ◽  
Schistocerca Gregaria ◽  
Locusta Migratoria ◽  
Extracellular Recording ◽  
Fibre Surface ◽  
Adductor Muscle ◽  
Muscle Fibres ◽  
Glass Capillary ◽  
Insect Muscle

1. Electrophoretic application of L-glutamate from glass capillary micro-pipettes was used to investigate the ‘spot sensitivity’ of the membrane of coxal adductor muscle fibres from adult specimens of Schistocerca gregaria Forskål and Locusta migratoria (L.). 2. Circumscribed spots could be detected on the fibre surface where brief applications of L-glutamate produced transient depolarizations (glutamate potentials). 3. Extracellular recording of excitatory junction potentials revealed that focal points of glutamate sensitivity are closely related to, and probably identical with, neuromuscular junctions. 4. Large doses readily de-sensitized the membrane to L-glutamate for periods greatly exceeding the duration of the glutamate potentials. 5. In chronically denervated muscles peaks of sensitivity could still be detected. 6. Spots sensitive to L-glutamate were not depolarized by D-glutamate. 7. The equilibrium point for glutamate potentials coincides with the equilibrium point of miniature excitatory potentials and lies between -10 and -25 mV.

THE POTENTIAL OF BACTERIA FOR THE MICROBIAL CONTROL OF GRASSHOPPERS AND LOCUSTS

1997 ◽  
Vol 129 (S171) ◽  
pp. 147-156 ◽  
Author(s):  
B. Zelazny ◽  
M.S. Goettel ◽  
B. Keller
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Bacillus Thuringiensis ◽  
Serratia Marcescens ◽  
Schistocerca Gregaria ◽  
Locusta Migratoria ◽  
Microbial Control ◽  
Control Agent ◽  
Promising Agent ◽  
Laboratory Populations ◽  
The Many

AbstractBacteria have been implicated in disease epizootics observed in field populations and laboratory-reared locusts and grasshoppers. Two species [Serratia marcescens Bizio and Pseudomonas aeruginosa (Schroeter) Migula] consistently infect locusts when ingested with food and can spread in laboratory populations. However, research on developing these organisms for microbial control of locusts and grasshoppers begun in the 1950s has not been continued. In recent years strains of Bacillus thuringiensis Berliner have been studied for activity against locusts and grasshoppers. Results of additional trials by the authors are reported. Among 393 B. thuringiensis isolates and 93 preparations of other sporeforming bacteria fed to nymphs of Locusta migratoria (L.) and/or Schistocerca gregaria Forsk., none has shown any pathogenicity to the insects. The recent discovery of novel B. thuringiensis strains active against various diverse pests and the many properties of a sporeforming bacterium that satisfy the requirements for a microbial control agent, and the development of Serratia entomophila as a promising agent for control of grass grubs, provide incentive to continue the search for an orthopteran-active sporeforming bacterium and to re-investigate the potential of non-sporeforming bacterial pathogens as microbial control agents of grasshoppers and locusts.

scholarly journals Screening and potent applicability analysis of commonly used pesticides against desert locust: an integrative entomo-informatics approach

2020 ◽  
Author(s):  
Anik Banik ◽  
Md. Fuad Mondal ◽  
Md. Mostafigur Rahman Khan ◽  
Sheikh Rashel Ahmed ◽  
Md. Mehedi Hasan
Keyword(s):  
Binding Affinity ◽  
Large Scale ◽  
Schistocerca Gregaria ◽  
Indian Subcontinent ◽  
Locusta Migratoria ◽  
Field Trials ◽  
The Other ◽  
List Type ◽  
Agricultural Pesticides ◽  
Global Threat

AbstractThe locust problem is a global threat for food security. Locusts can fly and migrate overseas within a zip and creating a large-scale devastation to the diversified agro-ecosystem. GIS based analysis showed the recent movement of locusts, among them Schistocerca gregaria and Locusta migratoria are predominant in Indian subcontinent and are found more notorious and devastating one. This devastation needs to be stopped to save human race from food deprivation. In our study, we screened some commonly used agricultural pesticides and strongly recommended three of them viz. biphenthrin, diafenthiuron and silafluofen which might be potential to control the desert locusts based on their binding affinity towards the locust’s survival proteins. Our phylogenetic analysis reveals that these three recommended pesticides might also show potency to the other locust species as well as they are also way safer than the other commercially available pesticides. These proposed pesticide’s bioactive analogs from fungus and bacteria may also show efficacy as next generation controlling measures of locust as well as different kind of pests. These recommended pesticides are expected to be highly effective against locusts and needs to bring forward by the entomologists’ by performing experimental field trials.HighlightsGIS map unmasked the 2020 migratory pattern of locusts which now predominant towards Indian subcontinent.Biphenthrin, diafenthiuron and silafluofen showed maximum binding affinity.Biphenthrin and diafenthiuron were relatively safer than silafluofen.Bioactive analogs from fungus and bacteria could be an alternative to control locusts.Pesticides inhibition hotspots for desert locusts were unrevealed.

Memoirs: The Neuro-Muscular Mechanism of the Gill of Pecten

1930 ◽  
Vol s2-73 (291) ◽  
pp. 365-392
Author(s):  
S. B. SETNA
Keyword(s):  
Feeding Habits ◽  
Adductor Muscle ◽  
The Body ◽  
Muscle Fibres ◽  
Direct Stimulation ◽  
Gill Filaments ◽  
Lateral Extent ◽  
Branchial Nerve ◽  
The Individual ◽  
Stimulation Of

Experimental. 1. The contraction of the adductor-muscle which follows stimulation of the palial nerve is preceded by a marked contraction of the ctenidial axis, so that the gill contracts before the adductor-muscle becomes active. This movement of the ctenidium is abolished if the main branchial nerve is cut near its origin. 2. The gills of Pecten possess a neuromuscular mechanism which is to some extent independent of the rest of the body, so that excised gills when stimulated react in the same way as an attached gill. 3. The lamellae of the gill possess two distinct types of movement. (a) When the surface of the gill is stimulated by contact with a glass rod or by carmine particles, the frontal surfaces of the two lamellae approach each other; the movement very often being executed by the lamella which is not actually being stimulated. The lateral extent of these movements (concertina movements) is roughly proportional to the intensity of the stimulus. Such movements normally appear to transfer the bulk of the material on to the mantle. Separation of the main branchial nerve abolishes these movements. (b) Each principal filament is capable of moving the ordinary filaments to which it is attached. This movement (flapping movement) is due to the movements of the interfilamentar junctions which alternatively move up and down at right angles to their length. This motion is independent of the branchial nerve and can be produced by direct stimulation of very tiny pieces of the individual filaments. 4. The significance of gill movements to feeding habits is discussed. The course of food particles depends on the nature of the stimuli affecting the gill. Histological. 5. The ctenidial axis and the principal filaments have a stratum of anastomosing nerve-cells which appear to form a true nerve-net comparable to that of the mantle. 6. The gill receives nerve-fibres from two sources, the brain and the visceral ganglion. The subsidiary branchial nerve is a structure hitherto unknown in the molluscan gill; so far its function is unknown. Each gill has four main longitudinal nerve-trunks. 7. The osphradium of the gill has a much more extensive distribution than has hitherto been supposed. 8. Two sets of muscles exist at the base of the gill-filaments, and these are responsible for movements of the lamellae. The muscle-fibres are non-striated. 9. The principal filaments are connected to the ordinary filaments by processes containing true muscle-cells, and by these cells movements of the filaments are effected.

The Cumulative Toxicity of Diniteo-O-cresol applied in Small Doses to Locusts

1957 ◽  
Vol 48 (2) ◽  
pp. 435-445 ◽  
Author(s):  
R. D. MacCuaig ◽  
K. F. Sawyer
Keyword(s):  
Single Dose ◽  
Schistocerca Gregaria ◽  
Locusta Migratoria ◽  
Lethal Dose ◽  
Cumulative Effect ◽  
Lethal Effect ◽  
Substantial Contribution ◽  
Successful Operation ◽  
Relative Susceptibility ◽  
Lethal Doses

SummaryBy the method of attacking flying swarms of locusts with insecticides sprayed directly into the swarm by relays of light aircraft, a proportion of the swarm receives a sub-lethal dose from each sortie. For successful operation it is essential that a substantial contribution to the final mortality should be produced by the accumulation of these sub-lethal doses on individual insects over a period of time. The object of the present experiments was to determine whether such doses applied at intervals are wholly additive in their effects. The poison used was dinitro-o-cresol (Mk. IV DNC solution) and to shorten the experimental procedure, the locusts, Schistocerca gregaria (Forsk.) and Locusta migratoria migratorioides (R. & F.), were dosed by means of a single drop of poison applied to the ventral surface of the abdomen by a micro-drop syringe.When locusts are given regular daily doses of DNC the doses are not wholly cumulative in their effect. After the second or third day the lethal effect of each dose becomes steadily less, and after the fourth or fifth day it tends to zero, representing a steady state in which the rates of application and loss of insecticidal activity in the survivors are equal.When the dose is applied in two halves with various time intervals between them, the cumulative effect during the first 24 hours is less in S. gregaria than in L. migratoria. In the latter species it is possible that sensitisation occurs. After three days, the first half-dose has fallen to an estimated 20 per cent, of its initial effectiveness in each species.These two species are equally susceptible to a single dose expressed as μg. DNC/g. body weight. The females are more resistant than the males to daily doses (relative susceptibility in S. gregaria, 1·54) but probably not to single doses (relative susceptibility, 1·09).Resistance to a daily dose correlates roughly with resistance to a single dose, the total dose required to produce 50 per cent, mortality in four days being about twice the LD50 for a single dose.If flight activity does not materially alter the present results, it is evident that the non-cumulative effects of sub-lethal doses could cause a serious loss in the efficiency of an air-spray operation if it were unduly prolonged. Thus a quantity of insecticide sufficient to kill over 99 per cent, of the locusts if applied as a single dose would kill less than 40 per cent, if the application were spread over four days.

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