Variations Des Lipides Au Cours De La Métamorphose De Tribolium Confusum Duval (ColéoptÈre: Tenebrionidae)

Abstract

1. Variations in lipid content of Tribolium confusum during metamorphosis has been studied. 2. Free lipids (petroleum ether soluble) is the primary source of transformation. An important decrease of low molecular weight fatty acids occurs with the prepupal molting. Pupation is characterized primarily by a decrease in the high molecular weight saturated fatty acids wich are metabolized gradually and lineary, while unsaturated fatty acids are utilized at a smaller rate and, free fatty acids accumulate. Adult molting results in a decrease of fatty acids of low molecular weight. 3. Bound lipids increase from prepupa to pupa, fall during the first two days of pupal stage then increase gradually to reach a value slightly exceeding that of the first day old pupa and decrease slightly in one day old adult. 4. There is an exchange between bound lipids and free lipids specially from larva to prepupa and from three days old pupa to the newly emerged adult. 5. the utilization of lipids during metamorphosis equal 76 per cent of the loss in dry matter and a small percentage is transformed into other substances.