The 2005 ESA Annual Meeting and Exhibition
December 15-18, 2005
Ft. Lauderdale, FL

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Sunday, December 18, 2005

Calorie restriction enhances longevity without reducing lifetime fecundity in female lubber grasshoppers (Romalea microptera)

John D. Hatle,, Sean M. Wells, Iris Cynthia Allen, L. Erin Fuller, Stephen Melnyk, and John Quattrochi. Univ of North Florida, Biology, 4567 St. Johns Bluff Rd S, Jacksonville, FL

Calorie restriction, under eating while avoiding malnutrition, enhances longevity in many organisms, often by allocating to storage, delaying fecundity or lowering hemolymph glucose. There is little information on hemolymph parameters of insects throughout the lifespan on calorie restriction. We tested several diets on longevity of female lubber grasshoppers and tracked hemolymph parameters throughout the lifespan of these same individuals. Constant calorie restriction (59% or 71% of ad libitum) increased longevity (Kaplan-Meier test, P=0.0002), and median adult ages at death were: ad libitum 83 d; 59% ad libitum 135 d; 71% of ad libitum greater than 165 d. These diets lowered body mass but did not reduce lifetime fecundity (ANOVA; P=0.275), hemolymph glucose levels (MANOVA; all P > 0.1) or hemolymph lipid levels (all P > 0.05). Calorie restriction transiently reduced the level of hemolymph storage proteins (i.e., hexamerins) around the time of first oviposition (P < 0.0001). Late-onset calorie restriction (60% of ad libitum after day 50 of adulthood) also increased longevity (median=136 d), but body mass gain did not keep pace with ad libitum grasshoppers during the first 50 d of adulthood when they were fed identically. Enhanced longevity due to calorie restriction likely is due to slowed aging, but this does not appear to result from reduced fecundity, glucose, or lipid, and only slightly from reduced storage.

Species 1: Orthoptera Romaleidae Romalea microptera (Eastern lubber grasshopper)
Keywords: hemolymph glucose, hexamerin storage proteins