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COMPETING ENERGY DEMANDS IN THE HAWKMOTH MANDUCA SEXTA
Author(s) -
Contreras Heidy Lorena,
Davidowitz Goggy
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.886.13
Subject(s) - manduca sexta , respirometry , specific dynamic action , manduca , biology , sphingidae , digestion (alchemy) , nectar , metabolic rate , energy expenditure , sucrose , insect , metabolic cost , zoology , ecology , food science , biochemistry , chemistry , endocrinology , pollen , chromatography , medicine , physical medicine and rehabilitation
In this study we used the hawkmoth, Manduca sexta, to investigate the effects that feeding status and activity level had on the metabolic rates of insects. Overall our interest lie in understanding how these organisms prioritizes and resolves the demand for energy from two simultaneous competing demands (digestion and activity). To determine the effect of feeding on the metabolic rate of M. sexta, we measured resting metabolic rates in unfed and fed individuals. Twenty moths (10 male and 10 female) were fed one of 5 treatments (water, 5, 15, 25, 35% sucrose) at random, and their metabolic rate was measured within an hour after feeding. The energetic cost of flight for unfed and fed individuals was measured by placing individual moths in a flight mill while a flow‐through respirometry system sampled air from the mill on a second‐by‐second basis. We found that the metabolic cost of activity and digestion are independent of each other and that there is an additive effect of digesting to the metabolic cost of activity. Furthermore, we found a significant increase in the cost of processing nectar containing 15% sucrose and above, which was observed when both resting and flight metabolic rates were measured. This is the first study addressing how insects resolve the conflict between competing energy demands.