Larval and adult diet affect phenotypic plasticity in thermal tolerance of the marula fly, Ceratitis cosyra (Walker) (Diptera: Tephritidae)

Abstract

IntroductionTemperature fluctuations are important for the distribution and survival of insects. Rapid hardening, a type of phenotypic plasticity, is an adaptation that can help individuals better tolerate lethal temperatures because of earlier exposure to a sublethal but stressful temperature. Nutrition and sex are also known to influence a species ability to tolerate thermal stress. This study determined the effects of larval diet, adult diet, sex and hardening on the thermal tolerance of Ceratitis cosyra (Walker) (Diptera: Tephritidae) at lower and upper lethal temperatures.MethodsLarvae were raised on either an 8% torula yeast (high) or a 1% torula yeast (low) larval diet and then introduced to one of three dietary regimes as adults for thermal tolerance and hardening assays: no adult diet, sugar only, or sugar and hydrolysed yeast diet. Flies of known weight were then either heat- or cold-hardened for 2 hours before being exposed to a potentially lethal high or low temperature, respectively.ResultsBoth nutrition and hardening as well as their interaction affected C. cosyra tolerance of stressful temperatures. However, this interaction was dependent on the type of stress, with nutrient restriction and possible adult dietary compensation resulting in improved cold temperature resistance only.DiscussionThe ability of the insect to both compensate for a low protein larval diet and undergo rapid cold hardening after a brief exposure to sublethal cold temperatures even when both the larva and the subsequent adult fed on low protein diets indicates that C. cosyra have a better chance of survival in environments with extreme temperature variability, particularly at low temperatures. However, there appears to be limitations to the ability of C. cosyra to cold harden and the species may be more at risk from long term chronic effects than from any exposure to acute thermal stress.

Developmental diet, life stage and thermal acclimation affect thermal tolerance of the fall armyworm, Spodoptera frugiperda

“…It also appears that this effect continues to the adult stage. A high protein larval diet has also been observed to improve adult thermal tolerance in D. melanogaster (Andersen et al, 2010) and newly emerged Ceratitis cosyra (Pullock et al, 2023). In the case of first instar larvae, where CT max was high but not affected by diet, it may be that high heat stress tolerance is aided by the emerging neonates consuming the protein‐rich egg shells (Capinera, 2017; Sparks, 1979), thereby adding protein to the diet.…”

Differential Cold Tolerance on Immature Stages of Geographically Divergent Ceratitis capitata Populations

“…Thermal biology of the adults of some tephritids including Bactrocera dorsalis (Hendel) [1,55], Bactrocera zonata (Saunders) [56], Bactrocera tryoni (Froggatt) [57,58], Bactrocera oleae (Rossi) [59], Bactrocera tau (Walker) [60], Ceratitis cosyra (Walker) [61], Ceratitis rosa (Karsch) [62], Ceratitis quilicii (De Meyer, Mwatawala and Virgilio) [63], Eurosta solidaginis (Fitch) [64][65][66][67], Rhagoletis cerasi (Linnaeus) [68] and Rhagoletis indifferens (Curran) [69] has already been investigated. Regarding medfly, its broader distribution may justify its great cold tolerance, which might determine the establishment of populations and their invasion success [13,70,71].…”