biostudies-literatureUnknown3Pullock DA<h4>Introduction</h4>Temperature 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 <i>Ceratitis cosyra</i> (Walker) (Diptera: Tephritidae) at lower and upper lethal temperatures.<h4>Methods</h4>Larvae 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.<h4>Results</h4>Both nutrition and hardening as well as their interaction affected <i>C. cosyra</i> 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.<h4>Discussion</h4>The 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 <i>C. cosyra</i> 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 <i>C. cosyra</i> to cold harden and the species may be more at risk from long term chronic effects than from any exposure to acute thermal stress.Frontiers in insect science1122161https://www.ebi.ac.uk/biostudies/studies/S-EPMC10926529biostudies-literatureLarval and adult diet affect phenotypic plasticity in thermal tolerance of the marula fly, <i>Ceratitis cosyra</i> (Walker) (Diptera: Tephritidae).PMC10926529Manrakhan APullock DAMalod KWeldon CWfalseLarval and adult diet affect phenotypic plasticity in thermal tolerance of the marula fly, <i>Ceratitis cosyra</i> (Walker) (Diptera: Tephritidae).<h4>Introduction</h4>Temperature 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 <i>Ceratitis cosyra</i> (Walker) (Diptera: Tephritidae) at lower and upper lethal temperatures.<h4>Methods</h4>Larvae 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.<h4>Results</h4>Both nutrition and hardening as well as their interaction affected <i>C. cosyra</i> 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.<h4>Discussion</h4>The 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 <i>C. cosyra</i> 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 <i>C. cosyra</i> to cold harden and the species may be more at risk from long term chronic effects than from any exposure to acute thermal stress.2023-01-01T00:00:00Z20232026-06-23T03:18:53.733Z2025-04-04T21:31:15.197ZS-EPMC109265293846950410.3389/finsc.2023.1122161