Oxidative Damage Is Influenced by Diet But Unaffected by Selection for Early Age of Oviposition in the Marula Fly, Ceratitis cosyra (Diptera: Tephritidae)

Abstract

The expression of life-history traits, such as lifespan or reproductive effort, is tightly correlated with the amount and blend of macronutrients that individuals consume. In a range of herbivorous insects, consuming high protein to carbohydrate ratios (P:C) decreases lifespan but increases female fecundity. In other words, females face a resource-based trade-off between lifespan and fecundity. Redox metabolism may help mediate this trade-off, if oxidative damage is elevated by reproductive investment and if this damage, in turn, reduces lifespan. Here, we test how diets varying in P:C ratio affect oxidative damage and antioxidant protection in female and male of the marula fly, Ceratitis cosyra (Diptera: Tephritidae). We use replicated lines that have been subjected to experimental evolution and differ in their lifespan and reproductive scheduling. We predicted that high fecundity would be associated with high oxidative damage and reduced antioxidant defences, while longer lived flies would show reduced damage and elevated antioxidant defences. However, higher levels of oxidative damage were observed in long-lived control lines than selection lines, but only when fed the diet promoting lifespan. Flies fed diets promoting female fecundity (1:4 and 1:2 P:C) suffered greater oxidative damage to lipids than flies fed the best diet (0:1 P:C) for lifespan. Total antioxidant capacity was not affected by the selection regime or nutrition. Our results reiterate the importance of nutrition in affecting life-history traits, but suggest that in C. cosyra, reactive oxygen species play a minimal role in mediating dietary trade-offs between lifespan and reproduction.

Changes in Biologically Active Compounds in Pinus sylvestris Needles after Lymantria monacha Outbreaks and Treatment with Foray 76B

“…For instance, insect defoliators partially destroy the photosynthetic apparatus resulting in excess energy storage and elevated concentration of reactive oxygen species (ROS) by causing photo-oxidative stress and activating photoprotective and antioxidative defense systems [ 21 ]. In response to oxidative stress plants undergo a process known as lipid peroxidation, which leads to alterations in the protein and nucleic acid composition of the cell membrane system [ 20 , 22 , 23 , 24 , 25 ]. Malondialdehyde (MDA) is a substance produced by membrane lipids whose higher levels in plant tissues signify a higher degree of damage [ 22 ].…”