Visual Scanning in the Desert Locust Schistocerca Gregaria Forskål

1959 ◽  
Vol 36 (3) ◽  
pp. 512-525 ◽  
Author(s):  
G. K. WALLACE
Keyword(s):  
Visual Field ◽  
Opposite Direction ◽  
Schistocerca Gregaria ◽  
Distance Estimation ◽  
The Body ◽  
Desert Locust ◽  
Visual Scanning

1. This paper describes a lateral swaying movement performed by desert locust nymphs. This movement is called ‘peering’. 2. The angle through which the body moves is influenced by the position of objects in the visual field, showing that the movement is related to vision. 3. When given a choice of two objects at different distances the nymphs show a preference for the nearer one. The estimation of the relative distances of the two objects is not achieved by a binocular method nor is it based on the angle subtended by the objects. 4. An experiment is described in which an object is moved while the insect is peering. If the object is moved in the opposite direction to the insect's motion the insect jumps short of the object. This seems to support the hypothesis that one of the functions of peering is to estimate distance by the extent of the movement over the retina of an object's image. 5. This method of distance estimation is discussed with relation to the binocular method. 6. It is suggested that in some cases the peering observed may represent a preliminary scanning of the visual field and may provide information about the finer details of the field.

The Histology and Histochemistry of Development and Resorption in the Terminal Oocytes of the Desert Locust, Schistocerca Gregaria

1963 ◽  
Vol s3-104 (65) ◽  
pp. 57-68
Author(s):  
O. LUSIS
Keyword(s):  
Corpus Luteum ◽  
Schistocerca Gregaria ◽  
The Body ◽  
Active Part ◽  
Desert Locust ◽  
Lipid Bodies ◽  
Follicular Cells ◽  
The Third ◽  
Postovulatory Follicle ◽  
Β Carotene

During vitellogenesis the follicular cells play an active part in the synthesis of yolk. The term ‘corpus luteum’ as applied to the ovary of the locust is invalid and two terms ‘white’ and ‘yellow’ follicle have been introduced to describe the separate identities of the normal and pathological postovulatory follicle. The protein yolk is a proteincarbohydrate compound, presumably a glycoprotein. Three kinds of lipid bodies are present; the first is a phospholipid, the second a combined phospholipid and triglyceride, and the third triglyceride. Lipids are coloured by dissolved β-carotene. Concentration or absorption of the lipids causes the crystallization of carotene and the formation of the pigment body. During resorption the follicular cells act as lecitholytic cells, first breaking down the protein and then the lipid yolk, and finally degenerating themselves. It is suggested that the oocytes have an inherent potential for resorption, the realization of which depends on various factors within the body.

The Role of Certain Optomotor Reactions in Regulating Stability in the Rolling Plane During Flight in the Desert Locust, Schistocerca Gregaria

1965 ◽  
Vol 42 (3) ◽  
pp. 385-407 ◽  
Author(s):  
LESLEY J. GOODMAN
Keyword(s):  
Visual Field ◽  
Schistocerca Gregaria ◽  
Longitudinal Axis ◽  
Rolling Plane ◽  
The Body ◽  
Head Movements ◽  
Light Reaction ◽  
The Central Nervous System ◽  
Control Stability

1. Locusts given freedom of movement in the rolling plane show complete lack of stability when flown in darkness, continually rotating about their longitudinal axis. 2. Stability in this plane appears to be controlled by two optomotor reactions, a dorsal light reaction and a reaction to the position of the horizon in the visual field. 3. Locusts behave as if there is a spatial representation of the visual area in the central nervous system and always turn so that the horizon is horizontal and the brighter half of the visual field uppermost in this representation. 4. The optomotor reactions control stability in the rolling plane indirectly through head movements, the head being orientated first and the body aligned with it by differential wing movements. 5. Relative head and body movements appear to be registered by two sets of proprioceptors, hair plates borne on the first cervical sclerites where they articulate with the head and a row of tactile hairs on the under edge of the prothorax. 6. The reactions described are operative in light intensities down to 0.1 ft.-lamberts, approximately comparable to tropical twilight conditions.

scholarly journals XXVII. On the nature of the force producing the motion of a body exposed to rays of heat and light

1876 ◽  
Vol 166 ◽  
pp. 715-724 ◽  
Keyword(s):  
Opposite Direction ◽  
Mechanical Action ◽  
The Body

Mr . Crookes has lately drawn attention to the mechanical action of a source of light on delicately suspended bodies in vacuo . I have made a few experiments which will, I think, throw some light on the cause of these phenomena, and assist us in the explanation of the manifold and striking experiments made by Mr. Crookes. Whenever we observe a force tending to drive a body in a certain direction we are sure to find a force equal in amount acting in the opposite direction on the body or on the bodies from which the force emanates. It was with the view of finding the seat of this reaction that I have made the experiments described in these pages.

THE HISTOLOGY OF THE GIANT FIBRE SYSTEM IN THE ABDOMINAL VENTRAL NERVE CORD OF THE DESERT LOCUST

1970 ◽  
Vol 102 (9) ◽  
pp. 1163-1168 ◽  
Author(s):  
W. D. Seabrook
Keyword(s):  
Single Cell ◽  
Nerve Cord ◽  
Ventral Nerve Cord ◽  
Schistocerca Gregaria ◽  
Desert Locust ◽  
Giant Fibre ◽  
Metathoracic Ganglion ◽  
Giant Fibres ◽  
Giant Fibre System

AbstractSchistocerca gregaria possess four neurones of giant fibre proportions within the abdominal ventral nerve cord. These fibres arise from single cell bodies in the terminal ganglionic mass and pass without interruption to the metathoracic ganglion. Fibres become reduced in diameter when passing through a ganglion. Branching of the giant fibres occurs in abdominal ganglia 6 and 7.

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