JH biosynthesis by corpora allata in locusts on artificial diet: Schistocerca gregaria vs Locusta migratoria migratorioides

1999 ◽  
Vol 124 ◽  
pp. S108
Author(s):  
Takashi Okuda ◽  
Satoshi Nakamura
Keyword(s):  
Artificial Diet ◽  
Schistocerca Gregaria ◽  
Locusta Migratoria ◽  
Corpora Allata ◽  
Locusta Migratoria Migratorioides

Observations on the effects of carotene on the growth and pigmentation of locusts

1961 ◽  
Vol 52 (1) ◽  
pp. 63-81 ◽  
Author(s):  
R. H. Dadd
Keyword(s):  
Artificial Diet ◽  
Schistocerca Gregaria ◽  
Locusta Migratoria ◽  
Corpora Allata ◽  
Blue Colour ◽  
Green Pigment ◽  
Nymphal Growth ◽  
Solitary Phase ◽  
Humoral Regulation ◽  
Dietary Deficiency

A method of obtaining locust eggs which could be expected to be deficient in carotene is described. It involved rearing a parental generation on an artificial diet which, because of certain pigmentation abnormalities it induced, was probably itself deficient in carotene.Using crowded hatchlings of Locusta migratoria (L.) from eggs thus modified, it was shown that they were sensitive to dietary carotene, whereas hatchlings from normal eggs were indifferent. The absence of carotene was marked by inferior growth, lessened activity and most notably by an extremely different coloration in both hoppers and adults. Without carotene, melanisation was absent or greatly reduced and in many cases the integument developed a greenish-blue colour. With carotene, heavy melanisation occurred in the hoppers, and the colour of the adults was characteristically gregarious.It was concluded that in normal eggs the amount of carotene present is usually sufficient to mask the expression of a dietary deficiency during nymphal growth, but that with normal eggs having low amounts of carotene, a dietary deficiency might become apparent as it did with modified eggs.It is suggested that the blue colour of modified Locusta hoppers reared without carotene is due to mesobiliverdin, a prochromogen of insectoverdin, the green pigment of the solitaria phase of locusts. Insectoverdin itself could not be formed because it contains carotenoids, and these were absent from the diet. The effect of extreme deprivation of carotene is therefore to induce solitaroid tendencies, notably in regard to colour (suppression of melanin and production of mesobiliverdin) but also in regard to activity.Crowded hoppers of Schistocerca gregaria (Forsk.) reared on synthetic diets lacking carotene usually had turquoise-blue blood by the fifth instar. It was shown, by the electrophoresis of yellow, green and blue bloods in parallel, that the blue chromoprotein of blue blood is the same as the blue chromoprotein of green blood. Its prosthetic pigment must therefore be mesobiliverdin.The abnormalities of coloration which arise in crowded Locusta and Schistocerca when deprived of carotene are normal in the solitary phase. Moreover, they resemble those abnormalities of coloration consequent upon the implantation of additional corpora allata into gregarious hoppers. The implications of this are discussed in relation to the validity of phase criteria, and an attempt is made to relate these findings to hypotheses on the humoral regulation of phase.

Operational Aspects of Locust Control

1966 ◽  
Vol 70 (672) ◽  
pp. 1077-1081
Author(s):  
D. Yeo
Keyword(s):  
Schistocerca Gregaria ◽  
Locusta Migratoria ◽  
Broad Band ◽  
Central Africa ◽  
Nomadacris Septemfasciata ◽  
Red Locust ◽  
Migratory Locust ◽  
Locusta Migratoria Migratorioides ◽  
The World ◽  
Locust Control

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.

The inhibitory effect of seedling grasses on feeding and survival of Acridids (Orthoptera)

1974 ◽  
Vol 64 (3) ◽  
pp. 413-420 ◽  
Author(s):  
E. A. Bernays ◽  
R. F. Chapman ◽  
J. Horsey ◽  
E. M. Leather
Keyword(s):  
Schistocerca Gregaria ◽  
Locusta Migratoria ◽  
Time Lapse ◽  
Inhibitory Effect ◽  
Nomadacris Septemfasciata ◽  
Activity Levels ◽  
Locusta Migratoria Migratorioides ◽  
Mature Leaves ◽  
Time Spent Feeding ◽  
Survival Studies

AbstractThe amounts eaten by Locusta migratoria migratorioides (R. & F.) on seedling grasses was less than on mature grasses in four other Acridids, Nomadacris septemfasciata (Serv.), Chortoicetes terminifera (Wlk.), Melanoplus sanguinipes (F.) and Schistocerca gregaria (Forsk.). Palatability of the young grasses increases with age, becoming maximal 6–10 weeks from the time of germination. Similar preferences were shown by other Acridids. Time-lapse film studies on Locusta showed that not only is less time spent feeding on seedling grasses, but that locomotor activity levels are considerably higher. Survival studies on the same species showed higher mortality on the seedlings as compared with the mature leaves at all stages of nymphal development, while on seedlings no individuals survived to the adult stage. Lipid-soluble materials were removed from seedling leaves with chloroform or acetone and this rendered them more acceptable, while the extract applied to mature leaves resulted in reduced palatability.

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