Kwang Pum Lee

Modest dietary restriction (DR) prolongs life in a wide range of organisms, spanning single-celled yeast to mammals. Here, we report the use of recent techniques in nutrition research to quantify the detailed relationship between diet, nutrient intake, lifespan, and reproduction in Drosophila melanogaster. Caloric restriction (CR) was not responsible for extending lifespan in our experimental flies. Response surfaces for lifespan and fecundity were maximized at different protein-carbohydrate int

Abstract. The interactive effects of macronutrient balance [protein (P) : carbohydrate (C) ratio] and dietary dilution by cellulose on nutritional regulation and performance were investigated in the generalist caterpillar Spodoptera littoralis (Boisduval). Caterpillars were reared through the final stadium on one of 20 foods varying factorially in macronutrient content (P + C%: 42, 33.6. 25.2 or 16.8%) and P : C ratio (5 : 1, 2 : 1, 1 : 1, 1 : 2 or 1 : 5). The animals compensate by eating more o

Abstract Temperature and nutrition are two prominent environmental variables influencing juvenile growth rate in ectotherms. These two factors interact in complex ways. Here, we present a comprehensive analysis of the interactive effects of temperature and nutrition on various components of fitness (growth rate, survival), food intake, and level of energy storage in an insect herbivore, caterpillars of Spodoptera exigua Hübner (Lepidoptera: Noctuidae). In a factorial experimental design, final‐i

Summary Food limitation is the most common environmental challenge faced by animals and the capacity of animals to survive prolonged periods of starvation is linked to their diet and nutritional status. The fruit flies of the genus D rosophila have been widely used to study the ecology and evolution of starvation resistance (SR), but the nutritional basis of their resistance to starvation has not yet been fully explored. We have taken a nutritionally explicit approach to investigate the quantita

The present study evaluates the interactive effects of protein quality and the ratio of protein to digestible carbohydrate on herbivore performance, various aspects of nutritional homeostasis (feeding and post-ingestive regulation) and food choice. In the first experiment, final-instar caterpillars of generalist-feeding African cotton leafworm Spodoptera littoralis (Boisduval) (Lepidoptera: Noctuidae) were confined to one of 20 diets varying in protein:carbohydrate (P:C) ratio (35:7, 28:14, 21:2

We examined the nutritional correlates of diet breadth in insect herbivores by comparing patterns of diet selection, nutrient balancing, post-ingestive utilization and development in two sister species of caterpillar and a hybrid between them. One species, Heliothis virescens (HV) has a broad host range, feeding on plants in at least 14 families. The other, Heliothis subflexa (HS), is a specialist on plants in the genus Physalis (Solanaceae). Experiments using synthetic foods showed that when th

Most ectotherms mature at a larger body size in colder conditions, a phenomenon known as the temperature-size rule. While a number of hypotheses have been proposed to explain this rule, little work has been done to understand it from a nutritional perspective. We have used the final-instar caterpillars of Spodoptera litura to investigate how dietary protein∶carbohydrate (P∶C) balance influences the relationship between temperature and body size. The strength and direction of the thermal reaction

Abstract Drosophila melanogaster Meigen (Diptera: Drosophilidae) is a key model insect for studying life span and aging. Many laboratory strains of D. melanogaster are currently used by laboratories worldwide, but they are known to vary considerably in their physiology, behavior, and life histories. Although the importance of dietary protein:carbohydrate (P:C) balance as a predominant determinant of life span and other life‐history traits has been highlighted in recent research, it remains unexp