Geographic variation and plasticity in climate stress resistance among southern African populations of Ceratitis capitata (Wiedemann) (Diptera: Tephritidae)

Abstract

Traits of thermal sensitivity or performance are typically the focus of species distribution modelling. Among-population trait variation, trait plasticity, population connectedness and the possible climatic covariation thereof are seldom accounted for. Here, we examine multiple climate stress resistance traits, and the plasticity thereof, for a globally invasive agricultural pest insect, the Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae). We also accounted for body size and population genetic connectivity among distinct populations from diverse bioclimatic regions across southern Africa. Desiccation resistance, starvation resistance, and critical thermal minimum (CTmin) and maximum (CTmax) of C. capitata varied between populations. For thermal tolerance traits, patterns of flexibility in response to thermal acclimation were suggestive of beneficial acclimation, but this was not the case for desiccation or starvation resistance. Population differences in measured traits were larger than those associated with acclimation, even though gene flow was high. Desiccation resistance was weakly but positively affected by growing degree-days. There was also a weak positive relationship between CTmin and temperature seasonality, but CTmax was weakly but negatively affected by the same bioclimatic variable. Our results suggest that the invasive potential of C. capitata may be supported by adaptation of tolerance traits to local bioclimatic conditions.

Differential sensitivity of bees to urbanization-driven changes in body temperature and water content

“…Weldon et al . 36 provide evidence that desiccation tolerance varies geographically among populations of Mediterranean fruit flies. Moreover, McCluney et al .…”

Adult diet of a tephritid fruit fly does not compensate for impact of a poor larval diet on stress resistance

“…We predicted that stress resistance would be improved by larval development in a nutrient-rich diet, leading to greater body reserves, but consumption of a nutrient-rich diet as an adult would compensate for poor stress resistance associated with a suboptimal larval diet. C. cosyra was chosen as the focus of this study due to availability of data on its adult nutritional intake targets and life history (Malod et al, 2017), its close phylogenetic relationship to other fruit fly species that have been the subject of water balance studies (Weldon et al, 2016(Weldon et al, , 2018 and because it exhibits relatively high desiccation resistance (Weldon et al, 2016). In addition, C. cosyra is an important quarantine pest across sub-Saharan Africa where it affects production of mangoes (Vayssieres et al, 2009;White and Elson-Harris, 1992).…”

Exploring the role of host specialisation and oxidative stress in interspecific lifespan variation in subtropical tephritid flies

“…To determine how lifespan was influenced by species relatedness, number of hosts, physiological parameters (TAC, protein and lipid oxidation) and body weight, we employed the approach used by Weldon et al 62 . The number of hosts (Table S2) refers to the number of confirmed host plants (i.e.…”