CAN NUTRITIONAL GEOMETRY MODULATE THE EFFECTS OF DIETARY RESTRICTION IN ACHETA DOMESTICUS?

Abstract

<p>This study was performed to better understand the physiological responses of the cricket <em>Acheta domesticus</em> to dietary restriction and nutritional geometry (relative nutritional balance). Dietary restriction in crickets decreases the growth rate, survivorship, maturation mass and delays maturation, but it has the benefit of increasing their maximum longevity. Measurements of maturation mass, maturation age and longevity were obtained and used to calculate adult duration, growth rate and survivorship. This experiment combined both dietary restriction and nutritional geometry. Treatments were dietary restricted and provided with one of three macronutrients: lipid, carbohydrate or protein. The macronutrients were predicted to modulate the effects of dietary restriction while still producing an increase in maximum longevity. The lifetime restricted males and females obtained the highest maximum longevity of all treatments. The females of the carbohydrate treatment experienced significant increases in survivorship when compared to the lifetime restricted treatment. The males of the carbohydrate treatment achieved the second highest maximum longevity as well as a significant increase in longevity when compared to the lipid and protein males. A significantly earlier maturation age was obtained by the carbohydrate males when compared to the lifetime restricted treatment. The protein females had a significantly higher maximum longevity than the control treatment. The lipid treatment had an extremely low survivorship, a decreased adult duration as well as a low maturation mass. In summary, carbohydrates decreased the maturation age and increased the survivorship of the female crickets and increased the longevity of the male crickets. The protein treatment did not obtain the expected increases in growth rates or maturation mass associated with high protein diets. Therefore, different high protein diets should be tested in conjunction with the carbohydrate diet, in order to offset the negative effects of dietary restriction.</p>