Changes in the Blood Potassium Concentration of the African Migratory Locust (Locusta Migratoria Migratorioides R. & F.) During Food Deprivation, and the Effect on Neuromuscular Activity

1954 ◽  
Vol 31 (2) ◽  
pp. 260-270 ◽  
Author(s):  
G. HOYLE

1. The concentrations of sodium and potassium in the haemolymph of the locust Locusta migratoria migratorioides R. & F. have been determined by flame photometry. The molar ratio of sodium to potassium is normally about 5 : 1. 2. During a short period of starvation the potassium content of the haemolymph decreases by as much as 50 %. 3. The change in potassium is adequate to account for observed differences in muscle membrane resting potentials and for variations in the mechanical responses of the muscles to nerve stimulation. 4. The ability of 5th-instar hoppers to respond to stimulation by hopping or jumping is increased after a short period of starvation owing to the increased mechanical responses of the muscles. 5. It is suggested that changes in diet potassium will be found to influence behaviour of locusts by the direct effect of the potassium on muscle fibre activity.

1954 ◽  
Vol 31 (2) ◽  
pp. 271-279
Author(s):  
PEGGY E. ELLIS ◽  
G. HOYLE

1. Hoppers of the locust Locusta migratoria migratorioides R. & F., which have been reared crowded, exhibit characteristic marching behaviour in the laboratory in foodless cages under standard conditions. 2. The rate of attainment of maximum marching by a given group of hoppers is greatest following a short period of starvation immediately preceding transfer to these conditions. 3. A meal of filter-paper soaked in sugar solution only, exerts no retarding effect on the rate of attainment of full marching, whilst if an adequate concentration of potassium salt is added in addition a definite retardation is observed. 4. In locusts actively feeding on grass the potassium content of the blood is relatively high, and it is suggested that this causes a reduced muscular efficiency which may explain retardation in attainment of full marching. 5. The marching pattern is the result of the activity of particular nerve centres which require a period of activation by a combination of factors before full expression is achieved. Two final factors are essential for the maintenance of the marching state, a low concentration of blood potassium and mutual stimulation by other marching hoppers.


Author(s):  
A.B. Gerus ◽  
◽  
Y.S. Tokarev ◽  
G.R. Lednev ◽  
M.B. Levchenko ◽  
...  

In this article we studied the conditions for keeping two species of gregarious locusts: the African migratory locust (Locusta migratoria migratorioides) and the Asian migratory locust (Locusta migratoria migratoria) in open and shaded areas. Based on the data obtained, it is shown that the survival rate of insects of the non-diapausal subspecies was higher in comparison with the obligate monovoltine.


1966 ◽  
Vol 70 (672) ◽  
pp. 1077-1081
Author(s):  
D. Yeo

The crops of every continent of the world have been devastated from time to time by locusts or grasshoppers. To mention three major locust species, the Desert Locust (Schistocerca gregaria Forsk.) has caused havoc in a broad band of the world stretching from East Pakistan to Senegal and from the Mediterranean to Central Africa, the Red Locust (Nomadacris septemfasciata Serv.) has infested East, Central and Southern Africa, and the African Migratory Locust (Locusta migratoria migratorioides Rch. and Frm.) has plagued most of Africa south of the Sahara.What happens in one part of a plague area can significantly affect the situation in others and locust control is therefore an international problem, requiring international co-operation. Many of the threatened areas are countries where standards of living are not high and local agriculture is a mainstay of the economy; the regions are often inhospitable and lack modern roads, aerodromes and lines of communication.


This paper completes the account of the embryology of Locusta migratoria migratorioides R. and F., which is referred to for brevity as Locusta migratoria , and describes the development of the principal organs of the body. In Part I (Roonwal, 1936, a ) of the present contribution, the early development up to the differentiation of the inner layer and the beginning of the definitive body segmentation was traced in detail. No special technique was employed beyond that already described in the earlier paper.


1952 ◽  
Vol 43 (1) ◽  
pp. 101-109 ◽  
Author(s):  
S. P. Cheu

The process of build-up of reserve substances in Locusta migratoria migratorioides (R. & F.) is very closely correlated with the feeding activity of the insect. Locusts attain their maximum body weight in the initial period before maturation. In the females there is one minor build-up period after each laying.As measured by the weight of faeces produced, the gregaria female consumes more food than the solitaria during development. It also has a lower rate of increase in body weight, maturation and oviposition.Locusts start to build up fat soon after the final ecdysis. The fat content reaches its maximum in the early part of adult life, and then begins to decline in both sexes of both phases.By far the greater part of the fat reserve thus built up in the gregaria female is used up before oviposition, and only a small amount goes to the making of the first egg-pod. The fat of the subsequent egg-pods (of both phases) is derived from the fat built up each time after a new egg-pod is laid.The solitaria females may mature their eggs at various stages in the development of the fat body. Those which have a longer pre-maturation period have a higher fat content.


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