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

Abstract

in herbivorous insects, the degree of host specialisation may be one ecological factor that shapes lifespan. Because host specialists can only exploit a limited number of plants, their lifecycle should be synchronised with host phenology to allow reproduction when suitable hosts are available. for species not undergoing diapause or dormancy, one strategy to achieve this could be evolving long lifespans. from a physiological perspective, oxidative stress could explain how lifespan is related to degree of host specialisation. oxidative stress caused by Reactive oxygen Species (RoS) might help underpin ageing (the Free Radical Theory of Aging (FRTA)) and mediate differences in lifespan. Here, we investigated how lifespan is shaped by the degree of host specialisation, phylogeny, oxidative damage accumulation and antioxidant protection in eight species of true fruit flies (Diptera: Tephritidae). We found that lifespan was not constrained by species relatedness or oxidative damage (arguing against the fRtA); nevertheless, average lifespan was positively associated with antioxidant protection. there was no lifespan difference between generalist and specialist species, but most of the tephritids studied had long lifespans in comparison with other dipterans. Long lifespan may be a trait under selection in fruitfeeding insects that do not use diapause.

Selecting on age of female reproduction affects lifespan in both sexes and age-dependent reproductive effort in female (but not male) Ceratitis cosyra

“…As the species does not undergo diapause, it would be advantageous if a fraction of the population, both females and males, survive until the next fruiting season. A previous study supports this idea, showing that C. cosyra has a particularly long lifespan among other tephritid flies (Malod et al 2020a). Nevertheless, in C. capitata courting has a direct cost on male lifespan (Papadopoulos et al 2010), and in D. melanogaster reproductive activity alters gene expression in males, which then results in reduced lifespan (Branco et al 2017).…”

“…Here, we used experimental evolution to examine the trade-off between lifespan and reproduction in females and males of the marula fruit fly, Ceratitis cosyra (Walker) (Diptera: Tephritidae). Several studies have documented the trade-off between lifespan and fecundity in females of various species of tephritids (Miyatake 1997;Carey et al 2005;Carey et al 2008a;Carey et al 2008b;Fanson et al 2009;Carey and Molleman 2010;Papadopoulos et al 2010;Carey 2011;Chen et al 2013;Papanastasiou et al 2013;Yap et al 2015;Malod et al 2017;Roets et al 2018;Carey et al 2020;Malod et al 2020a;Malod et al 2020b). Among these species, C. cosyra is one of the longest-lived (on average 104 to 161 days) (Roets et al 2018;Malod et al 2020a) and thus provides an interesting comparison to the much shorter-lived (ca., 30 to 60 days at 25°C; Mołoń et al 2020) model organism, D. melanogaster.…”

“…Several studies have documented the trade-off between lifespan and fecundity in females of various species of tephritids (Miyatake 1997;Carey et al 2005;Carey et al 2008a;Carey et al 2008b;Fanson et al 2009;Carey and Molleman 2010;Papadopoulos et al 2010;Carey 2011;Chen et al 2013;Papanastasiou et al 2013;Yap et al 2015;Malod et al 2017;Roets et al 2018;Carey et al 2020;Malod et al 2020a;Malod et al 2020b). Among these species, C. cosyra is one of the longest-lived (on average 104 to 161 days) (Roets et al 2018;Malod et al 2020a) and thus provides an interesting comparison to the much shorter-lived (ca., 30 to 60 days at 25°C; Mołoń et al 2020) model organism, D. melanogaster. We utilised selection regimes similar to those seen in classical Drosophila studies: we selected on age of oviposition such that only females that survived up to egg collection contributed to the next generation in the upward selected regime (Rose 1984;Arking 1987).…”

Role of the mtDNA Mutations and Mitophagy in Inflammaging

“…Similarly, the reduction of antioxidant enzymes increased MtDNA damage but did not influence lifespan [86][87][88]. Also, a high level of oxidative stress was noticed in some long-living species [89,90]. Altogether, this suggests that a mild level of oxidative stress could be beneficial for organisms, while, in the broader scope, the ROS-mediated theory of ageing requires further research to update [91].…”